Model 707A Switching Matrix Instruction Manual

Model 707A
Switching Matrix
Instruction Manual
Contains Operating and Servicing Information
707A-901-01 Rev. A / 9-98
WARRANTY
Keithley Instruments, Inc. warrants this product to be free from defects in material and workmanship for a period of 1 year from date of
shipment.
Keithley Instruments, Inc. warrants the following items for 90 days from the date of shipment: probes, cables, rechargeable batteries,
diskettes, and documentation.
During the warranty period, we will, at our option, either repair or replace any product that proves to be defective.
To exercise this warranty, write or call your local Keithley representative, or contact Keithley headquarters in Cleveland, Ohio. You will
be given prompt assistance and return instructions. Send the product, transportation prepaid, to the indicated service facility. Repairs
will be made and the product returned, transportation prepaid. Repaired or replaced products are warranted for the balance of the original warranty period, or at least 90 days.
LIMITATION OF WARRANTY
This warranty does not apply to defects resulting from product modification without Keithley’s express written consent, or misuse of
any product or part. This warranty also does not apply to fuses, software, non-rechargeable batteries, damage from battery leakage, or
problems arising from normal wear or failure to follow instructions.
THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING ANY IMPLIED
WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. THE REMEDIES PROVIDED HEREIN ARE
BUYER’S SOLE AND EXCLUSIVE REMEDIES.
NEITHER KEITHLEY INSTRUMENTS, INC. NOR ANY OF ITS EMPLOYEES SHALL BE LIABLE FOR ANY DIRECT, INDIRECT, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF ITS INSTRUMENTS AND
SOFTWARE EVEN IF KEITHLEY INSTRUMENTS, INC., HAS BEEN ADVISED IN ADVANCE OF THE POSSIBILITY OF
SUCH DAMAGES. SUCH EXCLUDED DAMAGES SHALL INCLUDE, BUT ARE NOT LIMITED TO: COSTS OF REMOVAL
AND INSTALLATION, LOSSES SUSTAINED AS THE RESULT OF INJURY TO ANY PERSON, OR DAMAGE TO PROPERTY.
Keithley Instruments, Inc. • 28775 Aurora Road • Cleveland, OH 44139 • 440-248-0400 • Fax: 440-248-6168 • http://www.keithley.com
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Model 707A Switching Matrix
Instruction Manual
©1998, Keithley Instruments, Inc.
All rights reserved.
Cleveland, Ohio, U.S.A.
First Printing, September 1998
Document Number: 707A-901-01 Rev. A
Manual Print History
The print history shown below lists the printing dates of all Revisions and Addenda created for this manual. The Revision
Level letter increases alphabetically as the manual undergoes subsequent updates. Addenda, which are released between Revisions, contain important change information that the user should incorporate immediately into the manual. Addenda are numbered sequentially. When a new Revision is created, all Addenda associated with the previous Revision of the manual are
incorporated into the new Revision of the manual. Each new Revision includes a revised copy of this print history page.
Revision A (Document Number 707A-901-01) ............................................................................ September 1998
All Keithley product names are trademarks or registered trademarks of Keithley Instruments, Inc.
Other brand and product names are trademarks or registered trademarks of their respective holders.
Safety Precautions
The following safety precautions should be observed before using
this product and any associated instrumentation. Although some instruments and accessories would normally be used with non-hazardous voltages, there are situations where hazardous conditions
may be present.
This product is intended for use by qualified personnel who recognize shock hazards and are familiar with the safety precautions required to avoid possible injury. Read the operating information
carefully before using the product.
The types of product users are:
Responsible body is the individual or group responsible for the use
and maintenance of equipment, and for ensuring that operators are
adequately trained.
Operators use the product for its intended function. They must be
trained in electrical safety procedures and proper use of the instrument. They must be protected from electric shock and contact with
hazardous live circuits.
Maintenance personnel perform routine procedures on the product
to keep it operating, for example, setting the line voltage or replacing consumable materials. Maintenance procedures are described in
the manual. The procedures explicitly state if the operator may perform them. Otherwise, they should be performed only by service
personnel.
Service personnel are trained to work on live circuits, and perform
safe installations and repairs of products. Only properly trained service personnel may perform installation and service procedures.
Exercise extreme caution when a shock hazard is present. Lethal
voltage may be present on cable connector jacks or test fixtures. The
American National Standards Institute (ANSI) states that a shock
hazard exists when voltage levels greater than 30V RMS, 42.4V
peak, or 60VDC are present. A good safety practice is to expect
that hazardous voltage is present in any unknown circuit before
measuring.
Users of this product must be protected from electric shock at all
times. The responsible body must ensure that users are prevented
access and/or insulated from every connection point. In some cases,
connections must be exposed to potential human contact. Product
users in these circumstances must be trained to protect themselves
from the risk of electric shock. If the circuit is capable of operating
at or above 1000 volts, no conductive part of the circuit may be
exposed.
As described in the International Electrotechnical Commission
(IEC) Standard IEC 664, digital multimeter measuring circuits
(e.g., Keithley Models 175A, 199, 2000, 2001, 2002, and 2010)
measuring circuits are Installation Category II. All other instruments’ signal terminals are Installation Category I and must not be
connected to mains.
Do not connect switching cards directly to unlimited power circuits.
They are intended to be used with impedance limited sources.
NEVER connect switching cards directly to AC mains. When connecting sources to switching cards, install protective devices to limit fault current and voltage to the card.
Before operating an instrument, make sure the line cord is connected to a properly grounded power receptacle. Inspect the connecting
cables, test leads, and jumpers for possible wear, cracks, or breaks
before each use.
For maximum safety, do not touch the product, test cables, or any
other instruments while power is applied to the circuit under test.
ALWAYS remove power from the entire test system and discharge
any capacitors before: connecting or disconnecting cables or jumpers, installing or removing switching cards, or making internal
changes, such as installing or removing jumpers.
Do not touch any object that could provide a current path to the
common side of the circuit under test or power line (earth) ground.
Always make measurements with dry hands while standing on a
dry, insulated surface capable of withstanding the voltage being
measured.
Do not exceed the maximum signal levels of the instruments and accessories, as defined in the specifications and operating information, and as shown on the instrument or test fixture panels, or
switching card.
When fuses are used in a product, replace with same type and rating
for continued protection against fire hazard.
Chassis connections must only be used as shield connections for
measuring circuits, NOT as safety earth ground connections.
If you are using a test fixture, keep the lid closed while power is applied to the device under test. Safe operation requires the use of a
lid interlock.
If a
screw is present, connect it to safety earth ground using the
wire recommended in the user documentation.
The ! symbol on an instrument indicates that the user should refer to the operating instructions located in the manual.
The
symbol on an instrument shows that it can source or measure 1000 volts or more, including the combined effect of normal
and common mode voltages. Use standard safety precautions to
avoid personal contact with these voltages.
The WARNING heading in a manual explains dangers that might
result in personal injury or death. Always read the associated information very carefully before performing the indicated procedure.
The CAUTION heading in a manual explains hazards that could
damage the instrument. Such damage may invalidate the warranty.
Instrumentation and accessories shall not be connected to humans.
Before performing any maintenance, disconnect the line cord and
all test cables.
To maintain protection from electric shock and fire, replacement
components in mains circuits, including the power transformer, test
leads, and input jacks, must be purchased from Keithley Instruments. Standard fuses, with applicable national safety approvals,
may be used if the rating and type are the same. Other components
that are not safety related may be purchased from other suppliers as
long as they are equivalent to the original component. (Note that selected parts should be purchased only through Keithley Instruments
to maintain accuracy and functionality of the product.) If you are
unsure about the applicability of a replacement component, call a
Keithley Instruments office for information.
To clean the instrument, use a damp cloth or mild, water based
cleaner. Clean the exterior of the instrument only. Do not apply
cleaner directly to the instrument or allow liquids to enter or spill
on the instrument.
707A Switching Matrix Specifications
Overview
CAPACITY: Six plug-in cards per mainframe.
EXPANSION CAPACITY: Daisy-chain expansion of up to four Slave units with one
Master unit.
ANALOG BACKPLANES: Backplanes provide automatic row expansion between
similar cards within one mainframe.
DISPLAY: 14-segment alphanumeric LED display, plus individual status LEDs.
MEMORY: Storage for 100 matrix setups, lithium battery backup.
PROGRAMMED SETTING TIME: 0 to 65 seconds in 1ms increments.
FRONT PANEL MENU: Digital I/O; External Trigger edge; Matrix Ready level; Master/
Slave operation; IEEE-488 address; Relay Settling Time; Self Test; Card Identify;
factory defaults.
TRIGGER SOURCES: External Trigger (TTL compatible, programmable edge, 600ns
minimum pulse width); IEEE-488 bus (TALK, GET, “X”); manual.
STATUS OUTPUT: Matrix Ready (TTL compatible, programmable high or low true):
goes false when relays are switched, true at end of Programmed Settling Time.
MAKE BEFORE BREAK, BREAK BEFORE MAKE: Programmable by row.
LIGHT PEN OPTION: Controls crosspoints, memories, make before break and break
before make. One light pen controls Master and all Slaves.
Execution Speed
MAXIMUM TRIGGER RATE: 200 setups per second (stepping through previously
stored setups with make-before-break and break-before-make disabled).
TRIGGER RESPONSE TIME:
External Trigger: <1ms.
IEEE-488 GET: <1ms.
RESPONSE TO IEEE-488 COMMAND (to close a single relay, excluding relay settling
time):
Stand Alone: <15ms.
Master and Four Slaves: <55ms.
DOWNLOAD TIME (one setup to 707A):
Stand Alone: 60ms typical.
IEEE-488 BUS IMPLEMENTATION
MULTILINE COMMANDS: DCL, LLO, SDC, GET, GTL, UNT, UNL, SPE, SPD
UNILINE COMMANDS: IFC, REN, EOI, SRQ, ATN.
INTERFACE FUNCTIONS: SH1, AH1, T6, TE0, L4, LE0, SR1, RL1, PP0, DC1, DT1, C0, E1.
PROGRAMMABLE PARAMETERS: All parameters programmable except for IEEE488 bus address and Master/Slave operating mode.
GENERAL
DIGITAL I/O (TTL compatible):
Data: 8 inputs, 8 outputs.
Control: Input Latch, Output Strobe.
REAR PANEL CONNECTORS:
Two BNC: External Trigger, Matrix Ready.
One DB-25: Digital I/O.
Two 8-pin DIN: Mater/Slave In, Mater/Slave Out.
One 6-pin Screw Terminal Plug: Relay Test.
ENVIRONMENTAL:
Operating: 0 to 50 C.
Storage: –25 to 65 C.
POWER: 100 to 240 VAC, 50–60Hz, 250VA maximum.
RELAY DRIVE: 5A minimum per card (slot).
EMC: Conforms with European Union Directive 89/336/EEC EN 55011,
EN 50082-1, EN 61000-3-3, FCC part 15 class B.
SAFETY: Conforms with European Union Directive 73/23/EEC EN 61010-1.
PHYSICAL: 356mm high × 432mm wide × 574mm deep (14 in × 17 in × 22.6 in). Net
weight without cards 16.5kg (36 lbs).
ACCESSORIES SUPPLIED: Instruction manual, power line cord, relay test
connector, fixed rack mounting hardware.
ACCESSORIES AVAILABLE:
Model 7078-PEN: Programming Light Pen (includes holder)
Model 7079:
Slide Rack Mounting Kit
Model 7078-DIN: 8-pin DIN cable (Master/Slave), 1.8m (6ft.)
Specifications are subject to change without notice.
Table of Contents
1
General Information
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.7.1
1.7.2
1.8
1.9
Introduction ........................................................................................................................................................
Features ..............................................................................................................................................................
Warranty information .........................................................................................................................................
Manual addenda .................................................................................................................................................
Safety symbols and terms ..................................................................................................................................
Specifications .....................................................................................................................................................
Unpacking and inspection . .................................................................................................................................
Inspection for damage ..............................................................................................................................
Shipment contents .....................................................................................................................................
Repacking for shipment .....................................................................................................................................
Optional accessories ...........................................................................................................................................
2
Card Installation
2.1
Installing and removing cards ............................................................................................................................ 2-1
3
Getting Started
3.1
3.2
3.3
3.4
3.5
3.5.1
3.5.2
3.5.3
3.5.4
3.6
3.6.1
3.6.2
3.6.3
3.6.4
Introduction ........................................................................................................................................................ 3-1
Front panel familiarization ................................................................................................................................. 3-1
Rear panel familiarization .................................................................................................................................. 3-6
Card connections ................................................................................................................................................ 3-8
Expanding matrix size ...................................................................................................................................... 3-10
Single unit expansion ............................................................................................................................. 3-10
Multiple unit expansion ......................................................................................................................... 3-16
System expansion issues ........................................................................................................................ 3-20
Documenting system configuration ....................................................................................................... 3-20
Basic switching operation ................................................................................................................................ 3-22
Power-up ................................................................................................................................................ 3-22
Selecting make/break and break/make rows .......................................................................................... 3-22
Modifying a relay setup ......................................................................................................................... 3-22
Storing setup and sending to relays ........................................................................................................ 3-23
1-1
1-1
1-1
1-1
1-2
1-2
1-2
1-2
1-2
1-2
1-2
i
4
Operation
4.1
4.2
4.3
4.3.1
4.3.2
4.3.3
4.3.4
4.3.5
4.3.6
4.4
4.4.1
4.4.2
4.4.3
4.4.4
4.4.5
4.4.6
4.5
4.6
4.7
4.8
4.9
4.9.1
4.9.2
4.9.3
4.9.4
4.9.5
4.9.6
4.9.7
4.9.8
4.9.9
4.10
4.10.1
4.10.2
4.11
4.11.1
4.11.2
4.11.3
4.11.4
4.11.5
4.11.6
4.12
Introduction ........................................................................................................................................................ 4-1
Setup data paths ................................................................................................................................................. 4-1
Power-up procedure ........................................................................................................................................... 4-2
Line voltage selection .............................................................................................................................. 4-2
Line power connections ........................................................................................................................... 4-2
Power switch ............................................................................................................................................ 4-2
Power-up self-test and messages ............................................................................................................. 4-2
Power-up configuration ........................................................................................................................... 4-3
Master/slave power-up ............................................................................................................................. 4-4
Displays and messages ...................................................................................................................................... 4-4
Alphanumeric display .............................................................................................................................. 4-4
Display messages ..................................................................................................................................... 4-5
IEEE-488 status indicators ...................................................................................................................... 4-6
Crosspoint display LEDs ......................................................................................................................... 4-6
Make/break and break/make LEDs ......................................................................................................... 4-8
Light pen .................................................................................................................................................. 4-8
Selecting crosspoint display ............................................................................................................................ 4-10
Modifying crosspoint display .......................................................................................................................... 4-10
Copying crosspoint display .............................................................................................................................. 4-11
Inserting and deleting stored setups ................................................................................................................. 4-12
Menu operations .............................................................................................................................................. 4-12
Digital I/O .............................................................................................................................................. 4-14
External trigger ...................................................................................................................................... 4-14
Matrix ready ........................................................................................................................................... 4-15
Stand-alone and master/slave ................................................................................................................ 4-16
IEEE-488 bus address ............................................................................................................................ 4-17
Relay (hardware) settling times ............................................................................................................. 4-18
Card labels ............................................................................................................................................. 4-18
Self-test .................................................................................................................................................. 4-18
Factory defaults ..................................................................................................................................... 4-18
Selecting switching parameters ....................................................................................................................... 4-19
Programmed settling time ...................................................................................................................... 4-19
Make/break and break/make rows ......................................................................................................... 4-19
Triggering ........................................................................................................................................................ 4-20
Trigger sources ...................................................................................................................................... 4-20
Front panel triggering ............................................................................................................................ 4-21
Trigger overrun conditions .................................................................................................................... 4-21
External trigger input ............................................................................................................................. 4-25
Matrix ready output ............................................................................................................................... 4-25
IEEE-488 bus triggering ........................................................................................................................ 4-25
Resetting .......................................................................................................................................................... 4-25
ii
5
IEEE-488 Programming
5.1
5.2
5.3
5.4
5.5
5.6
5.7
5.7.1
5.7.2
5.7.3
5.7.4
5.8
5.8.1
5.8.2
5.8.3
5.8.4
5.8.5
5.8.6
5.8.7
5.8.8
5.8.9
5.9
5.9.1
5.9.2
5.9.3
5.9.4
5.9.5
5.9.6
5.9.7
5.9.8
5.9.9
5.9.10
5.9.11
5.9.12
5.9.13
5.9.14
5.9.15
5.9.16
5.9.17
5.9.18
5.9.19
5.9.20
5.9.21
5.9.22
5.9.23
5.9.24
5.9.25
5.9.26
5.9.27
5.10
5.11
Introduction ........................................................................................................................................................ 5-1
IEEE-488 quick start .......................................................................................................................................... 5-1
Bus cable connections ........................................................................................................................................ 5-3
Interface function codes ..................................................................................................................................... 5-5
Primary address programming ........................................................................................................................... 5-6
QuickBASIC programming ............................................................................................................................... 5-7
Front panel aspects of IEEE-488 operation ....................................................................................................... 5-8
Front panel error messages ...................................................................................................................... 5-8
Status indicators ....................................................................................................................................... 5-9
Local key ................................................................................................................................................ 5-10
Concurrent front panel and bus operation .............................................................................................. 5-10
General bus command programming ............................................................................................................... 5-10
Overview ................................................................................................................................................ 5-10
REN (remote enable) ............................................................................................................................. 5-10
IFC (interface clear) ............................................................................................................................... 5-11
LLO (local lockout) ............................................................................................................................... 5-11
GTL (go to local) ................................................................................................................................... 5-11
DCL (device clear) ................................................................................................................................. 5-11
SDC (selective device clear) .................................................................................................................. 5-11
GET (group executive trigger) ............................................................................................................... 5-11
SPE, SPD ( serial polling) ...................................................................................................................... 5-11
Device-dependent command (DDC) programming ......................................................................................... 5-12
Overview ................................................................................................................................................ 5-12
A — External trigger .............................................................................................................................. 5-16
B — Matrix ready .................................................................................................................................. 5-17
C — Close crosspoint ............................................................................................................................ 5-18
D — Display .......................................................................................................................................... 5-18
E — Edit pointer .................................................................................................................................... 5-19
F — Enable/disable triggers ................................................................................................................... 5-19
G — Data format .................................................................................................................................... 5-20
H — Hit key ........................................................................................................................................... 5-25
I — Insert blank setup ............................................................................................................................ 5-26
J — Self-test ........................................................................................................................................... 5-26
K — EOI and hold-off ........................................................................................................................... 5-26
L — Download setups ............................................................................................................................ 5-27
M — SRQ and serial poll byte ............................................................................................................... 5-28
N — Open crosspoint ............................................................................................................................. 5-30
O — Digital output ................................................................................................................................ 5-30
P — Clear crosspoints ............................................................................................................................ 5-31
Q — Delete setup ................................................................................................................................... 5-31
R — Restore defaults ............................................................................................................................. 5-32
S — Programmed settling time .............................................................................................................. 5-32
T — Trigger ........................................................................................................................................... 5-33
U — Status ............................................................................................................................................. 5-34
V — Make/break .................................................................................................................................... 5-39
W — Break/make ................................................................................................................................... 5-39
X — Execute .......................................................................................................................................... 5-40
Y — Terminator ..................................................................................................................................... 5-41
Z — Copy setup ..................................................................................................................................... 5-41
Relay command combinations ......................................................................................................................... 5-42
Timing considerations ...................................................................................................................................... 5-43
iii
6
Principles of Operation
6.1
6.2
6.3
6.3.1
6.3.2
6.3.3
6.4
6.4.1
6.4.2
6.5
6.5.1
6.5.2
6.5.3
6.5.4
6.6
6.7
6.7.1
6.7.2
6.8
6.9
6.10
Introduction ........................................................................................................................................................ 6-1
Overall function description .............................................................................................................................. 6-1
Microcomputer .................................................................................................................................................. 6-1
Reset circuit ............................................................................................................................................. 6-1
Address decoding ..................................................................................................................................... 6-2
Memory .................................................................................................................................................... 6-4
Relay control circuitry ....................................................................................................................................... 6-4
Switching card interface .......................................................................................................................... 6-6
Switching card logic ................................................................................................................................ 6-6
Display circuitry .............................................................................................................................................. 6-10
Display data ........................................................................................................................................... 6-13
Front panel keys ..................................................................................................................................... 6-13
Display interface .................................................................................................................................... 6-13
Refresh display/read keyboard .............................................................................................................. 6-14
Light pen interface............................................................................................................................................ 6-14
Master/slave circuitry ...................................................................................................................................... 6-15
Serial communication ............................................................................................................................ 6-15
Control signals ....................................................................................................................................... 6-17
Digital I/O ........................................................................................................................................................ 6-17
IEEE-488 bus interface .................................................................................................................................... 6-17
Power supply ................................................................................................................................................... 6-19
7
Maintenance
7.1
7.2
7.3
7.4
7.5
7.6
7.7
7.8
7.9
7.9.1
7.9.2
7.9.3
7.9.4
7.9.5
7.10
7.11
7.11.1
7.11.2
Introduction ........................................................................................................................................................ 7-1
Line voltage sensing .......................................................................................................................................... 7-1
Fuse replacement ............................................................................................................................................... 7-2
Fixed rack installation ........................................................................................................................................ 7-2
Disassembly ....................................................................................................................................................... 7-5
Backplane jumpers ............................................................................................................................................. 7-7
Battery replacement ........................................................................................................................................... 7-9
Static-sensitive devices ...................................................................................................................................... 7-9
Mainframe troubleshooting ............................................................................................................................... 7-9
Recommended test equipment ............................................................................................................... 7-10
Power-up self-test .................................................................................................................................. 7-10
Power supply checks .............................................................................................................................. 7-10
Digital board checks .............................................................................................................................. 7-10
Display board checks ............................................................................................................................. 7-14
Using an extender card .................................................................................................................................... 7-16
Cleaning ........................................................................................................................................................... 7-16
Backplane .............................................................................................................................................. 7-16
Fan filter ................................................................................................................................................. 7-16
8
Replaceable Parts
8.1
8.2
8.3
8.4
8.5
Introduction ........................................................................................................................................................
Parts lists ............................................................................................................................................................
Ordering information .........................................................................................................................................
Factory service ...................................................................................................................................................
Component layouts and schematics ...................................................................................................................
iv
8-1
8-1
8-1
8-1
8-1
A
Card Configuration Worksheet
B
IEEE-488 Bus Overview
B.1
B.2
B.3
B.3.1
B.3.2
B.3.3
B.4
B.4.1
B.4.2
B.4.3
B.4.4
B.4.5
B.4.6
B.4.7
B.4.8
B.5
Introduction .......................................................................................................................................................
Bus description ..................................................................................................................................................
Bus lines ............................................................................................................................................................
Data lines .................................................................................................................................................
Bus management lines ............................................................................................................................
Handshake lines ......................................................................................................................................
Bus commands ..................................................................................................................................................
Uniline commands ..................................................................................................................................
Universal multiline commands ...............................................................................................................
Addressed multiline commands ..............................................................................................................
Address commands .................................................................................................................................
Unaddress commands .............................................................................................................................
Command codes ......................................................................................................................................
Typical command sequences ..................................................................................................................
IEEE command groups ...........................................................................................................................
Interface function codes ....................................................................................................................................
B-1
B-1
B-3
B-3
B-3
B-3
B-4
B-4
B-5
B-5
B-5
B-5
B-5
B-7
B-7
B-8
v
List of Illustrations
2
Card Installation
Figure 2-1
Installing a matrix card .............................................................................................................................. 2-2
3
Getting Started
Figure 3-1
Figure 3-2
Figure 3-3
Figure 3-4
Figure 3-5
Figure 3-6
Figure 3-7
Figure 3-8
Figure 3-9
Figure 3-10
Figure 3-11
Figure 3-12
Figure 3-13
Figure 3-14
Figure 3-15
Model 707A front panel ............................................................................................................................. 3-2
Setup data transfers .................................................................................................................................... 3-3
Model 707A rear panel .............................................................................................................................. 3-7
Connecting instruments to rows ................................................................................................................. 3-8
Connecting instruments to columns ........................................................................................................... 3-9
Backplane buses ....................................................................................................................................... 3-10
Backplane expansion of analog bus #1 .................................................................................................... 3-11
Backplane expansion of analog bus #2 .................................................................................................... 3-12
Backplane expansion of analog bus #3 .................................................................................................... 3-13
Row connection examples ....................................................................................................................... 3-14
Example of partial matrix expansion ....................................................................................................... 3-15
Model 7071 row connections of stand-alone units .................................................................................. 3-16
Example of master/slave interconnect cables .......................................................................................... 3-17
Master/slave column locations ................................................................................................................. 3-18
Example of master/slave row expansion .................................................................................................. 3-19
4
Operation
Figure 4-1
Figure 4-2
Figure 4-3
Figure 4-4
Figure 4-5
Figure 4-6
Figure 4-7
Figure 4-8
Figure 4-9
Figure 4-10
Figure 4-11
Figure 4-12
Figure 4-13
Figure 4-14
Figure 4-15
Figure 4-16
Figure 4-17
Figure 4-18
Paths for relay setup data ........................................................................................................................... 4-1
Alphanumeric display ................................................................................................................................ 4-4
Crosspoint display ...................................................................................................................................... 4-7
Light pen .................................................................................................................................................... 4-9
Crosspoint display keys ........................................................................................................................... 4-10
Data entry keys ......................................................................................................................................... 4-11
Memory keys ............................................................................................................................................ 4-12
Digital I/O port ......................................................................................................................................... 4-14
Rear panel BNC jacks .............................................................................................................................. 4-14
Sample external trigger pulses ................................................................................................................. 4-15
Sample matrix ready pulses ..................................................................................................................... 4-15
Master/slave connectors ........................................................................................................................... 4-16
IEEE-488 bus connector .......................................................................................................................... 4-17
Switching keys ......................................................................................................................................... 4-19
Trigger keys ............................................................................................................................................. 4-20
Timing without make/break or break/make rows .................................................................................... 4-22
Timing with either make/break or break/make rows ............................................................................... 4-23
Timing with both make/break and break/make rows ............................................................................... 4-24
vii
5
IEEE-488 Programming
Figure 5-1
Figure 5-2
Figure 5-3
Figure 5-4
Figure 5-5
Figure 5-6
Figure 5-7
Figure 5-8
Figure 5-9
Figure 5-10
Figure 5-11
Figure 5-12
Figure 5-13
Figure 5-14
Figure 5-15
Figure 5-16
Figure 5-17
Figure 5-18
Figure 5-19
Figure 5-20
Figure 5-21
Figure 5-22
Figure 5-23
Flowchart of example program .................................................................................................................. 5-2
IEEE-488 connector ................................................................................................................................... 5-3
IEEE-488 connections ............................................................................................................................... 5-3
IEEE-488 connector location ..................................................................................................................... 5-4
Contact assignments .................................................................................................................................. 5-5
IEEE-488 indicators ................................................................................................................................... 5-9
LOCAL key ............................................................................................................................................. 5-10
External trigger pulse ............................................................................................................................... 5-16
Matrix ready pulse ................................................................................................................................... 5-17
G0 and G1 full output formats ................................................................................................................. 5-22
G2 and G3 inspect output formats ........................................................................................................... 5-23
G4 and G5 condensed output formats ..................................................................................................... 5-23
G6 and G7 binary output formats ............................................................................................................ 5-24
SRQ mask and serial poll byte format ..................................................................................................... 5-28
READY and MATRIX READY signal timing ....................................................................................... 5-33
U0 machine status word ........................................................................................................................... 5-35
U1 error status word ................................................................................................................................ 5-35
U3 relay step pointer ................................................................................................................................ 5-36
U4 number of slaves ................................................................................................................................ 5-37
U5 card identification .............................................................................................................................. 5-37
U6 relay settling time ............................................................................................................................... 5-37
U7 digital input ........................................................................................................................................ 5-38
U8 relay test input .................................................................................................................................... 5-38
6
Principles of Operation
Figure 6-1
Figure 6-2
Figure 6-3
Figure 6-4
Figure 6-5
Figure 6-6
Figure 6-7
Figure 6-8
Figure 6-9
Figure 6-10
Figure 6-11
Figure 6-12
Model 707A block diagram ....................................................................................................................... 6-2
Digital board block diagram ...................................................................................................................... 6-3
RAM and battery backup ........................................................................................................................... 6-5
Switching card interface simplified schematic .......................................................................................... 6-7
Switching card interface timing diagram ................................................................................................... 6-8
Typical switching card logic block diagram .............................................................................................. 6-8
IDDATA timing diagram .......................................................................................................................... 6-9
Display board diagram ............................................................................................................................. 6-11
Display interface simplified schematic .................................................................................................... 6-13
Light pen interface simplified schematic ................................................................................................. 6-14
Master/slave interface simplified schematic ............................................................................................. 6-16
Digital I/O interface simplified schematic ............................................................................................... 6-18
7
Maintenance
Figure 7-1
Figure 7-2
Figure 7-3
Figure 7-4
Figure 7-5
Figure 7-6
Figure 7-7
Figure 7-8
Figure 7-9
Figure 7-10
Captive nut installation .............................................................................................................................. 7-3
Nut bar on flange ....................................................................................................................................... 7-3
Chassis support sizing ................................................................................................................................ 7-4
Chassis support assembly .......................................................................................................................... 7-4
Right side view of disassembly ................................................................................................................. 7-5
Front view of disassembly ......................................................................................................................... 7-6
Backplane jumpers ..................................................................................................................................... 7-8
Troubleshooting programs ....................................................................................................................... 7-14
Relay control waveforms ......................................................................................................................... 7-15
Display interface waveforms ................................................................................................................... 7-15
viii
B
IEEE-488 Bus Overview
Figure B-1
Figure B-2
Figure B-3
IEEE-488 bus configuration ...................................................................................................................... B-2
IEEE-488 handshake sequence ................................................................................................................. B-3
Command codes ........................................................................................................................................ B-6
ix
List of Tables
3
Getting Started
Table 3-1
Table 3-2
Table 3-3
Table 3-4
Table 3-5
Row-column and column-column paths .................................................................................................... 3-9
Matrix and multiplexer cards ................................................................................................................... 3-13
Model 707A external expansion cables ................................................................................................... 3-15
Response time comparisons ..................................................................................................................... 3-20
Model 707A card configuration ............................................................................................................... 3-21
4
Operation
Table 4-l
Table 4-2
Table 4-3
Table 4-4
Table 4-5
Table 4-6
Table 4-7
Table 4-8
Setup data paths ......................................................................................................................................... 4-2
Power-up, reset, and factory defaults ......................................................................................................... 4-3
Error messages ........................................................................................................................................... 4-5
Information messages ................................................................................................................................ 4-6
Menu operations ....................................................................................................................................... 4-13
Status of slave unit controls ..................................................................................................................... 4-17
Make/break and break/make front panel operation .................................................................................. 4-20
Front panel messages for trigger sources ................................................................................................. 4-20
5
IEEE-488 Programming
Table 5-1
Table 5-2
Table 5-3
Table 5-4
Table 5-5
Table 5-6
Table 5-7
Table 5-8
Table 5-9
Table 5-10
Table 5-11
Table 5-12
Table 5-13
Sample strings ............................................................................................................................................ 5-2
Contact assignments ................................................................................................................................... 5-5
Model 707A interface function codes ........................................................................................................ 5-6
Basic IEEE-488 statements ........................................................................................................................ 5-7
Front panel IEEE-488 error messages ........................................................................................................ 5-8
General bus commands/BASIC statements ............................................................................................. 5-11
Factory default, power-up, and DCL/SDC conditions ............................................................................. 5-12
Order of command execution ................................................................................................................... 5-13
DDC summary ......................................................................................................................................... 5-14
Master/slave setup example ..................................................................................................................... 5-21
Byte counts for data format ...................................................................................................................... 5-22
Typical transmission and hold-off times — stand-alone ......................................................................... 5-44
Typical transmission and hold-off times — master and one slave .......................................................... 5-45
6
Principles of Operation
Table 6-1
Display segment assignments .................................................................................................................. 6-12
xi
7
Maintenance
Table 7-1
Table 7-2
Table 7-3
Table 7-4
Table 7-5
Table 7-6
Table 7-7
Table 7-8
Table 7-9
Table 7-10
Table 7-11
Line fuse values ......................................................................................................................................... 7-2
Fixed rack parts .......................................................................................................................................... 7-2
Recommended troubleshooting equipment ............................................................................................. 7-10
Power supply checks ................................................................................................................................ 7-10
Microcomputer checks ............................................................................................................................. 7-11
Relay control checks ................................................................................................................................ 7-11
Display interface checks .......................................................................................................................... 7-12
Digital I/O checks .................................................................................................................................... 7-12
Light pen checks ...................................................................................................................................... 7-13
Master/slave checks ................................................................................................................................. 7-13
Display board checks ............................................................................................................................... 7-14
8
Replaceable Parts
Table 8-1
Table 8-2
Table 8-3
Table 8-4
Table 8-5
Table 8-6
Digital board assembly ..............................................................................................................................
Display board assembly .............................................................................................................................
Backplane assembly ...................................................................................................................................
Voltage regulator assembly .......................................................................................................................
Chassis assembly .......................................................................................................................................
Miscellaneous ............................................................................................................................................
8-2
8-3
8-3
8-3
8-4
8-4
B
Table B-1
Table B-2
Table B-3
Table B-4
Table B-5
Table B-6
xii
IEEE-488 bus command summary ............................................................................................................ B-4
Hexadecimal and decimal command codes ............................................................................................... B-5
Typical addressed command sequence ...................................................................................................... B-7
Typical common command sequence ........................................................................................................ B-7
IEEE command groups .............................................................................................................................. B-7
Model 707A interface function codes ........................................................................................................ B-8
1
General Information
1.1
Introduction
• An active front panel LED display shows the current
relay status, a stored setup, or an editing scratchpad.
This section contains general information about the Model
707A Switching Matrix. The Model 707A is designed as a
programmable switch for connecting signal paths in a matrix
topology. It is for applications requiring a large-scale matrix
(up to 576 crosspoints per mainframe and 2880 crosspoints
per master/slave configuration). Plug-in cards are available
for general and special purpose switching applications.
• High-speed triggering of stored setups.
Section 1 is arranged as follows:
• An optional light pen is available for interactive controlling of relay states, editing stored relay setups, and
selecting make/break and break/make rows.
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
1.2
Features
Warranty Information
Manual Addenda
Safety Symbols and Terms
Specifications
Unpacking and Inspection
Repacking for Shipment
Optional Accessories
Features
• Make/break and break/make switching are programmable by rows. Operation is transparent to the user and
independent of the relay setup.
• With five units connected in a master/slave configuration, the maximum matrix size is eight rows by 360 columns (2880 crosspoints on one IEEE-488 address).
1.3
Warranty information
Warranty information is located at the front of this instruction manual. Should your Model 707A require warranty service, contact the Keithley representative or authorized repair
facility in your area for further information. When returning
the mainframe for repair be sure to fill out and include the
service form at the back of this manual to provide the repair
facility with the necessary information.
Key features of the Model 707A Switching Matrix include:
• The six-slot mainframe accepts any mix of 8-row by
12-column matrix cards.
• Rows are extended within the mainframe to minimize
system wiring and interconnect requirements.
• Storage of 100 sets of relay setups, which can be
uploaded or downloaded through the IEEE-488 interface.
1.4
Manual addenda
Any improvements or changes concerning the mainframe or
manual will be explained in an addendum included with the
unit. Be sure to note these changes and incorporate them into
the manual before using or servicing the unit.
1-1
General Information
1.5
Safety symbols and terms
The following symbols and terms may be found on an instrument or used in this manual:
The ! symbol on an instrument indicates that the user
should refer to the operating instructions located in the
instruction manual.
The
symbol on an instrument shows that high voltage
may be present on the terminal(s). Use standard safety precautions to avoid personal contact with these voltages.
The WARNING heading used in this manual explains dangers that could result in personal injury or death. Always read
the associated information very carefully before performing
the indicated procedure.
The CAUTION heading used in this manual explains hazards that could damage the instrument. Such damage might
invalidate the warranty.
1.6
Specifications
Model 707A specifications can be found at the front of this
manual. These specifications are exclusive of the matrix card
specifications, which are located in their appropriate instruction manual.
1.7
Unpacking and inspection
1.7.1 Inspection for damage
Upon receiving the Model 707A, carefully unpack it from its
shipping carton and inspect the unit for any obvious signs of
physical damage. Report any damage to the shipping agent
immediately. Save the original packing carton for possible
future reshipment.
1.7.2 Shipment contents
The following items are included with every Model 707A
order:
• Model 707A Switching Matrix
• Model 707A Instruction Manual
• Power line cord
• Relay test connector
• Fixed rack mounting hardware
• Additional accessories as ordered
1-2
1.8
Repacking for shipment
Should it become necessary to return the Model 707A for
repair, carefully pack the unit in its original packing carton
or the equivalent, and include the following information:
• Call the repair department at 1-800-552-1115 for a
Repair Authorization (RMA) number.
• Advise as to the warranty status of the mainframe.
• Write ATTENTION REPAIR DEPARTMENT and the
RMA number on the shipping label.
• Fill out and include the service form located at the back
of this manual.
1.9
Optional accessories
The following accessories are available for the Model 707A:
Model 7070 Universal Adapter Card — The Model 7070
card installs in the Model 707A and is jumper-selectable for
use either as a backplane extender or a breadboard. It has
quick disconnect screw terminals and 10-ft. ribbon cables.
Model 7071 General Purpose Matrix Card — The Model
7071 card has 8 rows by 12 columns of 3-pole Form A
switching for general purpose applications. It installs in the
Model 707A and has mass terminated connectors in addition
to quick-disconnect screw terminals.
Model 7071-4 General Purpose Matrix Card — The Model
7071-4 card has dual 4 rows by 12 columns of 3-pole Form
A, which is also configurable as 8 rows by 12 columns of 3pole Form A or 4 rows by 24 columns of 3-pole Form A. It
installs in the Model 707A and has 38 pin quick disconnect
connectors.
Model 7072 Semiconductor Matrix Card — The Model 7072
card has 2 rows by 12 columns of 2-pole Form A for low current switching, 4 rows by 12 columns of 2-pole Form A for
general purpose switching, and 2 rows by12 columns of
1-pole Form A for C-V switching. It installs in the Model
707A and has 3-lug triaxial connectors.
Model 7072-HV Semiconductor Matrix Card — The Model
7072-HV card has 2 rows by 12 columns of 2-pole Form A
for low current paths to jumpers, 4 rows by 12 columns of 2pole Form A for general purpose paths to the backplane, and
2 rows by 12 columns of 1-pole Form A for C-V paths to
jumpers. It installs in the Model 707A and has 3-lug triaxial
connectors.
General Information
Model 7073 Coaxial Matrix Card — The Model 7073 card
has 8 rows by 12 columns of 1-pole Form A switching (up to
30MHz) for applications with single-ended instruments. It
installs in the Model 707A and has BNC connectors.
Model 7079 Slide Rack Mounting Kit — The Model 7079
kit consists of two sets of support brackets, equipment slides,
and hardware for mounting the Model 707A in a standard
19-inch equipment rack or cabinet.
Model 7074-D General Purpose Multiplexer Card — The
Model 7074-D card has eight banks of 1 row by 12 columns
of 3-pole Form A. Adjacent banks can be connected together
or jumpers can be removed to isolate any bank from the
backplane. It installs in the Model 707A and has four 75 pin
bank connections and one 38 pin connector for row connections.
Model 7007 Shielded IEEE-488 Cables — The Model 7007
connects the Model 707A to the IEEE-488 bus using
shielded cables to reduce electromagnetic interference
(EMI). The Model 7007-1 is one meter (3.3 ft.) long and has
an EMI shielded IEEE-488 connector at each end. The
Model 7007-2 cable is identical to the Model 7007-1, but is
2m (6.6 ft.) long.
Model 7075 2-Pole Multiplexer Card — The Model 7075
card has eight banks of 1 row by 12 columns of 2-pole Form
A. Adjacent banks can be connected together or jumpers can
be removed to isolate any bank from the backplane. It installs
in the Model 707A and has nine 25 pin subminiature D connectors, eight for bank connections and one for row connection.
Model 7051 BNC to BNC Cables — The Model 7051 cables
are for making connections to External Trigger and Matrix
Ready on the Model 707A rear panel. The Model 7051-2 is
a 50Ω BNC to BNC cable (RG-58C), which is 0.6m (2 ft.)
long. The Model 7051-5 cable is identical to the Model
7051-2, but is 1.5m (5 ft.) long.
Model 7076 Dual 2-Pole Matrix Card — The Model 7076
card has dual 4 rows by 12 columns of 2-pole Form A, which
is also configurable as 8 rows by 12 columns of 2-pole Form
A. Jumpers can be removed to isolate any bank from the
backplane. It installs in the Model 707A and has three 25 pin
subminiature D connectors, two for column connection and
one for row connection.
Model 7077 Isolated Coaxial Matrix Card — The Model
7077 card has 8 rows by 12 columns of 2-pole Form A. It
installs in the Model 707A and has BNC connectors.
Model 7078-DIN 8-pin DIN Cable — The Model 7078-DIN
cable has two 8-pin circular (DIN) connectors and is 1.8m (6
ft.) long. Multiple cables are used for connecting Model
707A units in a master/slave configuration through the rear
panel master/slave connectors.
Model 7078-PEN Programming Light Pen — The Model
7078-PEN connects to the Model 707A front panel. It is used
to toggle the states of crosspoint LEDs, make/break LEDs,
and break/make LEDs. A pen holder is included.
Model 7172 Low Current Matrix Card — The Model 7172
card has 8 rows by 12 columns of 2-pole Form A. Expanding
the columns can be done internally by connecting the rows
of multiple 7172 cards together with coax jumpers. It installs
in the Model 707A and has 3-lug triaxial connectors.
Model 7173-50 High Frequency 2-Pole Matrix Card — The
Model 7173-50 card has 4 rows by 12 columns of 2-pole
Form C with row isolators. It installs in the Model 707A and
has BNC connectors.
Model 7174A Low Current Matrix Card — The Model
7174A card has 8 rows by 12 columns of 2-pole Form A.
Expanding the columns can be done internally by connecting
the rows of multiple 7174A cards together with coax jumpers. It installs in the Model 707A and has 3-lug triaxial connectors.
Model 8000-14 Enclosures — The Model 8000-14 is a
19”-wide by 14”-high open-backed steel enclosure. It is supplied with hardware to mount a bench-top Model 707A The
top cover of the enclosure can be removed to access jumpers
between cards installed in a Model 707A.
1-3
2
Card Installation
2.1
Installing and removing cards
Before operating the Model 707A in a test environment,
matrix cards (up to six per mainframe) must be installed into
the mainframe. Note that matrix cards are not necessary to
program setups. Setups for master/slave configurations can
be programmed as long as the MASTER/SLAVE OUT to
MASTER/SLAVE IN loop connections are present. (See
paragraph 3.5.2.)
2. Remove the slot cover from the desired slot.
3. With one hand grasping the card's handle, and the other
supporting its weight, line up the card with the card
guides in the slot. Ensure that the component side is facing the fan of the mainframe.
4. Slide the card into the mainframe until it is fully seated
in the backplane connectors. Finger-tighten the springloaded mounting screws at the back of the card to lock
it in place.
WARNING
WARNING
Before installing/removing cards or
making card connections, turn off mainframe power and disconnect the line
cord. Also, ensure that no power is
applied from the user's circuit.
The mounting screws must be secured to
ensure a proper chassis ground connection between the card and the mainframe. Failure to properly secure this
ground connection may result in personal injury or death due to electric
shock.
Install a card in the Model 707A as follows, using Figure 2-1
as a guide. Instructions specific to each card can be found in
the appropriate card manual.
CAUTION
Do not touch the card surfaces, connectors, or components to avoid contamination that could degrade card
performance.
NOTE
Some cards have connectors that are inaccessible once the card is fully inserted into
the mainframe (e.g., the quick disconnect
terminal blocks on Model 7071 cards). In
these cases, connect wires to the row and
column terminal blocks before seating it in
the backplane connectors.
1. Ensure that the access door on top of the mainframe is
fully closed and locked down. (The bottom side of the
access door has card guides.)
2-1
Card Installation
NOTE
The SMB coax jumpers used between
Model 7072 cards do not have to be
installed before the cards are inserted. Use
the access door on top of the mainframe
for this purpose. (Because of the access
door, the Model 7079 slide rack kit is recommended for rack-mounted units.)
Figure 2-1
Installing a matrix card
2-2
5. To remove a matrix card, first turn off the mainframe
and disconnect the line cord. Ensure no voltage is
applied from the user's circuit. Remove any internal
cabling between cards through the unit's access door.
Loosen the spring-loaded mounting screws and pull out
the card by its handle.
3
Getting Started
3.1
Introduction
This section contains introductory information on operating
your instrument and is intended to help you get your Model
707A up and running as quickly as possible. It includes a
brief description of operating controls and connections.
Once you are familiar with the material presented here, refer
to Section 4 for more detailed information.
Section 3 is organized as follows:
3.2 Front Panel Familiarization: Briefly describes each
front panel control and outlines display operations.
3.3 Rear Panel Familiarization: Outlines each aspect of
the Model 707A rear panel, including connectors.
3.4 Card Connectors: Describes where to connect instruments and DUTs to the matrix rows and columns.
3.5 Expanding Matrix Size: Discusses methods for
expanding the matrix, both internal to the mainframe
and with multiple units.
3.6 Basic Switching Operation: Provides a general procedure for powering up the Model 707A, choosing make/
break or break/make operation, modifying the crosspoint display, storing the setup, and sending the setup to
the relays.
3.2
Front panel familiarization
An overview of the Model 707A operation is given in the following paragraphs. The front panel of the instrument is
shown in Figure 3-1. Figure 3-2 illustrates setup data transfers within the Model 707A. This pictorial will be helpful in
understanding the operations of individual front panel keys.
All front panel keys except POWER are momentary contact
switches. Some keys have an LED to indicate the selected
function. The keys are color coded into functional groups for
ease of operation.
3-1
Getting Started
Figure 3-1
Model 707A front panel
3-2
Getting Started
Stored
Setup #100
Model 707A
Front Panel
Crosspoint Display
Model 707A
Internal
Memory
Stored
Setup #1
Crosspoint Relays
Model 7X7X
Matrix Cards
Figure 3-2
Setup data transfers
3-3
Getting Started
POWER — AC power switch turns the unit on or off.
DELETE — Deletes the setup at the location shown in the
MEMORY STEP field. Moves higher stored setups down
one memory location.
Crosspoint display group
MEMORY — Displays a stored relay setup (from location
shown in MEMORY STEP field) on the crosspoint display
and lights the MEMORY indicator.
RELAYS — Displays the current relay setup on the crosspoint display and lights the RELAYS indicator.
CROSSPOINT DISPLAY MODIFIED — Lights when
changes are made to the crosspoint display (by front panel
keys or light pen), making it different from the original
configuration.
COPY DISPLAY → MEMORY — Copies the displayed
cross-point configuration to the location shown in the MEMORY STEP field.
COPY DISPLAY → RELAYS — Copies the displayed
cross-point configuration to the relays.
AUTOMATIC (COPY DISPLAY → RELAYS) — When
this LED is lit, any change to the crosspoint display is sent to
the relays at the same time. The pushbutton toggles the LED
on and off.
Scroll group
SCROLL
— If MEMORY indicator is lit, increments
MEMORY STEP field and displays setup on crosspoint
LEDs. If RELAYS indicator is lit, increments RELAY STEP
field, displays setup on crosspoint LEDs, and sends setup to
relays. Also used for scrolling up through a list of multiple
choice parameters.
SCROLL
— Same actions as the SCROLL
except that it increments and scrolls down.
key
Memory group
INSERT — Inserts a blank setup at the location shown in
the MEMORY STEP field. Moves higher stored setups up
one memory location.
3-4
MENU — Steps through the available menu items.
• View digital input, program digital output.
• Select whether rising or falling edge of External Trigger
pulse triggers Model 707A.
• Select an active high or active low Matrix ready output
signal.
• Select master/slave or stand-alone operation.
• Program IEEE-488 address.
• View longest relay setting time of present card
configuration.
• View unit configuration by slot number and card model
number.
• Execute self-test.
• Restore factory defaults (and clear stored setups).
Programmable parameters can be changed with the
SCROLL or data entry keys and then pressing enter.
Switching group
SETTLING TIME — Displays the current value of programmed settling time. (This delay begins after the relay settling time.) To change the value, enter between 0-65000msec
and press ENTER.
MAKE/BREAK — Selects rows to operate as make/break
(make-before-break) for all setups. First enter row designation (A-H), then press MAKE/BREAK to toggle the state for
that row and immediately reprogram the Model 707A for the
new operation.
BREAK/MAKE — Same action as MAKE/BREAK except
that it selects break/make (break-before-make) rows.
(Selecting a row for break/make de-selects it for make/break
and vice versa.)
LOCAL — When in remote (REMOTE on), returns the
Model 707A to local mode (REMOTE off). It restores operation of other front panel controls unless LLO (Local Lockout) is in effect.
Getting Started
Trigger group
ENABLE — Toggles between triggers enabled and triggers
disabled. When triggers are enabled, the LED is lit.
SOURCE — Displays current trigger source. Use SCROLL
keys to display sources, then press ENTER to select the
desired source:
TRIG ON TALK
TRIG ON GET
TRIG ON X
TRIG ON EXT
TRIG ON KEY
-
IEEE talk command
IEEE GET command
IEEE X command
External trigger pulse (rear panel
input)
- Front panel MANUAL key only
MANUAL — Generates a trigger from front panel if triggers are enabled (no matter which trigger source is selected).
If the trigger source is TRIG ON KEY, only the MANUAL
key generates a trigger.
CLOSE — Same action as OPEN key except that it turns on
the crosspoint LED and relay.
ALPHANUMERIC DISPLAY — A 14-character display
that can show:
• Error messages.
• Menu item selections.
• Last setup sent from memory to the relays (RELAY
STEP field).
• Last setup recalled from memory to the crosspoint display (MEMORY STEP field).
• Trigger source.
• Programmed settling time.
• Alphanumeric key presses (row/column addresses,
setup locations).
IEEE-488 status indicators
DATA ENTRY (A-H, 0-9) — These keys are for entering
row/column addresses and setup locations, selecting make/
break and break/make rows, and entering various numeric
values.
CANCEL — If the value in the alphanumeric display has
been modified, this key restores the current parameter value.
If the value in the alphanumeric display has not been modified, this key returns the Model 707A to the previous display.
CANCEL also exits from menu mode if no changes have
been made.
ENTER — If the value in the alphanumeric display has been
modified, pressing this key stores the parameter value. Also
invokes immediate action items from the menu and exits
menu mode (except when digital I/O is displayed).
RESET — Performs the same functions as cycling power
(all relays are opened, triggers are disabled, RELAY STEP to
000, MEMORY STEP to 001, etc.), except powerup selfchecking and master/slave loop initialization.
CLEAR — Turns off all crosspoint display LEDs. If the
AUTOMATIC (COPY DISPLAY → RELAYS) indicator is
lit, all relays are opened immediately.
OPEN — Turns off crosspoint LED of row/column shown
on alphanumeric display. If the AUTOMATIC (COPY DISPLAY → RELAYS) indicator is lit, the corresponding relay
opens immediately.
TALK, LISTEN, REMOTE — These three LED indicators
apply to instrument operation over the IEEE-488 bus. The
TALK and LISTEN indicators show when the unit has been
addressed to talk or listen. REMOTE turns on to show when
the unit is in the IEEE-488 remote state. See Section 4 for
detailed information on operation over the bus.
CROSSPOINT DISPLAY LEDs — Show open and closed
crosspoints of the current relay setup, a stored relay setup, or
an edited relay setup. Each LED block of 8 rows by 12 columns shows on/off states of one card. States can be changed
by front panel keys, triggers, or optional light pen. Crosspoint configurations can be stored in memory or sent to
relays.
MAKE/BREAK ROW LEDs — Show which rows are
selected for make/break operation. The LEDs can be turned
on or off by the MAKE/BREAK, BREAK/MAKE keys or by
an optional light pen.
BREAK/MAKE ROW LEDs — Same function as MAKE/
BREAK row LEDs except for showing which rows are
selected for break/make operation. Note that selecting a row
for break/make de-selects it for make/break and vice versa.
LIGHT PEN — An optional input device for toggling the
on/off state of the Crosspoint Display LEDs, MAKE/
BREAK row LEDs, and BREAK/MAKE row LEDs. One
light pen is used. to control the LEDs of up to five Model
707A mainframes.
3-5
Getting Started
3.3
Rear panel familiarization
An overview of the rear panel of the Model 707A is in the
paragraphs that follow. The rear panel is shown in Figure
3-3. In addition to the various connectors, a column locator
diagram for a master or stand-alone unit is provided on the
rear panel.
RELAY TEST — A 6-pin quick-disconnect terminal block
with logic ground and four logic inputs for testing crosspoint relay closures. Wiring between this terminal block and
rows A and B of any card in the group of cards to be tested is
necessary for the test.
CARD SLOTS — The Model 707A accepts up to six plugin matrix cards (8 rows by 12 columns) per mainframe.
DIGITAL I/O — A DB-25 connector for the TTL-compatible digital I/O with data lines for eight inputs and eight outputs. It also contains control lines for handshaking (Input
Latch and Output Strobe). Input lines are viewed and output
lines are programmed through a menu item.
MASTER/SLAVE OUT — An 8-pin DIN connector for
connecting a cable to the next mainframe in a master/slave
daisy chain configuration.
IEEE-488 INTERFACE — This connector interfaces the
Model 707A to the IEEE-488 bus. IEEE interface function
codes are marked adjacent to the connector.
MASTER/SLAVE IN — An 8-pin DIN connector for connecting a cable from the previous mainframe in a master/
slave daisy chain configuration.
AC RECEPTACLE — Power is applied through the supplied power cord to the 3-terminal AC receptacle.
EXTERNAL TRIGGER INPUT — A BNC jack for
applying a trigger pulse to change to the next relay setup, if
triggers are enabled and TRIG ON EXT is selected as the
source. Pulses must be TTL-compatible, negative-or
positive-going (selected by a menu item), with a duration
greater than 600nsec.
MATRIX READY OUTPUT — A BNC jack providing a
TTL-compatible, high- or low-true level (selected by a menu
item). It goes false when relays are switched and goes true
after the sum of the relay setting time and the programmed
settling time.
3-6
LINE FUSE — The line fuse provides protection for the AC
power line input. The fuse rating must match the line voltage
setting.
FAN FILTER — The fan filter keeps dirt from being drawn
into the instrument by the internal cooling fan. The filter
should be kept clean to ensure proper instrument cooling.
Getting Started
Figure 3-3
Model 707A rear panel
3-7
Getting Started
3.4
Card connections
Each card designed for the Model 707A is configured as an
8-row by 12-column matrix. The rows are lengthened by
adding columns from other cards (of the same model number). Connections for row expansion are usually internal to
the mainframe, either through the analog backplane buses or
with user-installed jumpers, depending on the card model.
Rows can also be expanded across mainframe boundaries,
either in a master/slave or stand-alone/stand-alone configuration. In a master/slave configuration of up to five mainframes, the rows are extended to 360 columns maximum.
(Paragraph 3.5 describes master/slave expansion.)
Expansion of rows leads to a long, narrow matrix. If your
application requires few instruments and many DUTs, connect the instruments to rows (up to 8) and the DUTs to columns (up to 72 with 6 cards). This connection scheme is
optimum because the row-column path has only one crosspoint, as shown in Figure 3-4.
Selecting the row connections for instruments is important
with cards designed for multiple applications. Using the
Model 7072 as an example, the recommended connections
are as follows:
• Rows A and B (1ow current) — Picoammeters,
electrometers.
• Rows C through F (general purpose) — DMMs,
sources.
• Rows G and H (C-V characteristics) — C-V analyzers.
An alternate connection scheme of the long, narrow matrix
has all connections on the columns, both instruments and
DUTs. This is done when the series of tests requires a large
number of instruments and DUTs, with only a few signals for
each test. As seen in Figure 3-5, with two cards, two crosspoint relays must be closed to complete a path from columncolumn (a safety benefit when sourcing). Paths with multiple
crosspoints have additional path resistance and contact
potential than single crosspoint paths.
DUT
Source
A
Source
B
Measure
C
Measure
D
E
F
G
H
1
2
3
4
5
6
7
8
9
10
11 12
Note : One crosspoint closure yields a row-column path.
Figure 3-4
Connecting instruments to rows
3-8
Crosspoint programming becomes more complex with
column-column paths because of the number of possible
paths for large matrices and the choice of rows to complete
the path. (See Table 3-1.)
The row completion choice for column-column paths on
multiple application cards follows the recommendations
given previously for row-column paths. That is, with a
Model 7072 card, close a crosspoint relay in row A or B for
low current applications, row C, D, E, or F for general purpose switching, and row F or G for C-V switching.
Getting Started
DUT Test
Fixture
BNC cables connect to row terminals
of both cards.
BNC Cable - Columns
Ribbon Cable - Rows
Instrumentation
Simplified
Equivalent Circuit
DUTs
(14 connections)
1
2
3
4
5
6
7
8
9
10 11
Instrumentation
(10 connections)
12
1
2
3
4
5
6
7
8
9
10 11
12
A
B
C
D
E
F
G
H
Master
Slave
Note: BNC matrix cards shown. Other card connections similar.
Figure 3-5
Connecting instruments to columns
Table 3-1
Row-column and column-column paths
Connection scheme
Crosspoints per path
Possible paths for
Possible paths for
8 rows by 12 columns 8 rows by 72 columns
Row-column
1
96
576
Column-column
2
66
2556
Notes:
1. The crosspoints per path do not take into account any isolator relays that may be present on a card.
2. Each column-column path can be through one of eight rows (e.g., connect column 1 to column 2 by closing A1 and A2,
or close B1 and B2, etc.)
3-9
Getting Started
3.5
Expanding matrix size
The 8-row by 12-column matrix cards of the Model 707A
mainframe are building blocks for larger matrices. Matrix
expansion is accomplished by two methods:
• Internal to the mainframe — The Model 707A backplane automatically extends rows from other like cards.
Special purpose rows (not extended by the backplane)
are extended by user-installed jumpers between adjacent cards.
The third analog bus expands eight rows of a signal HI path
and a common ground (chassis). The common ground surrounds the HI path and separates adjacent rows, as shown in
Figure 3-9. These rows are for 1-pole switching in common
ground (high frequency) systems or floating signals (with an
additional row for switching low).
J101
• External to the mainframe — A master/slave connection of up to five mainframes is an extension of the rows
(up to 8 rows by 360 columns). Also, individual rows
and columns can be connected between cards or
between mainframes.
J106
Analog Bus #1
J101 - J106, Pins 1 - 22
4 Rows - HI and LO
The paragraphs that follow explain matrix expansion in
detail.
Analog Bus #2
3.5.1 Single unit expansion
Expansions to a single unit are either connections internal to
the mainframe or external connections of the cards in the
same mainframe.
J101 - J106, Pins 23 - 86
8 Rows - HI, LO, Guard
Analog
Buses
Internal expansion and isolation
Internal expansion is done automatically through the Model
707A backplane. Each of the six mainframe slots has three
card edge connectors, as shown in Figure 3-6 and described
below:
J112
J107
Analog Bus #3
• Upper connectors (J101-J106) — Consists of two analog buses (pins 1-22 and pins 23-86) to expand card
rows.
J107 - J112, Pins 1 - 34
8 Rows - HI, and Chassis Ground
• Middle connectors (J107-J112, 34-pin connectors) —
Consists of a third analog bus to expand card rows.
• Lower connectors (J113-J118, 30-pin connectors) —
This is a digital bus for mainframe control of the matrix
cards.
The first analog bus expands signals HI and LO of four
rows. The LO of an individual row surrounds the HI path and
is between the adjacent rows, as shown in Figure 3-7. These
rows are used for 2-pole, general purpose switching.
The second analog bus expands signals HI, LO, and
GUARD of eight rows. The GUARD of each row surrounds
the HI and LO paths and separates adjacent rows. See Figure
3-8. These rows are used for 3-pole, general purpose switching and when the guard signal needs to be switched.
3-10
J113
J118
J113 - J118, Pins 1 - 30
Digital
Bus
Slot 1
Figure 3-6
Backplane buses
Slots 2 - 5
Slot 6
Getting Started
HI
Row
Row
1
Row
HI
2
1
HI
1
2
HI
LO
LO
LO
LO
LO
LO
LO
HI
HI
HI
HI
LO
LO
LO
LO
Row
2
LO
J101
J102
LO
LO
LO
J103 - J105
J106
LO
HI
HI
HI
HI
LO
LO
LO
LO
LO
LO
LO
LO
HI
HI
HI
HI
22 LO
LO 21
Slot 1
21
22 LO
Slot 2
21
Slots 3 - 5
22
LO
Slot 6
Figure 3-7
Backplane expansion of analog bus #1
3-11
Getting Started
Guard
23
24
HI
Row
Row
Row
Row
Row
Row
Guard
23
24
HI
Guard
HI
LO
LO
LO
LO
Guard
Guard
Guard
Guard
Guard
Guard
HI
HI
HI
Guard
HI
LO
LO
LO
LO
Guard
Guard
Guard
Guard
Guard
Guard
Guard
HI
HI
HI
Guard
HI
LO
LO
LO
LO
Guard
Guard
Guard
Guard
Guard
Guard
Guard
HI
HI
HI
Guard
HI
LO
LO
LO
LO
Guard
Guard
Guard
Guard
J101
J102
Guard
Guard
HI
J103 - J105
J106
Guard
HI
HI
LO
LO
LO
LO
Guard
Guard
Guard
Guard
Guard
Guard
Guard
HI
HI
HI
Guard
HI
LO
LO
LO
LO
Guard
Guard
Guard
Guard
Guard
Guard
Guard
HI
HI
HI
Guard
HI
LO
LO
LO
LO
Guard
Guard
Guard
Guard
Guard
Guard
Guard
HI
HI
HI
Guard
HI
LO
Guard
LO
85
86
Guard
Slot 1
Figure 3-8
Backplane expansion of analog bus #2
3-12
24
Guard
HI
Row
23
HI
Guard
Row
Guard
LO
85
86
Slot 2
LO
Guard
85
Slots 3 - 5
86
Slot 6
Guard
Getting Started
1
Row
Row
Row
Row
Row
Row
Row
Row
2
1
2
1
2
HI
HI
HI
HI
HI
HI
HI
HI
HI
HI
HI
HI
HI
HI
HI
HI
J107
HI
J108
HI
HI
J112
J109 - J111
HI
HI
HI
HI
HI
HI
HI
HI
HI
HI
HI
33
34
Slot 1
HI
33
HI
34
33
Slot 2
Slots 3 - 5
34
Slot 6
Chassis
Figure 3-9
Backplane expansion of analog bus #3
Matrix cards for use in the Model 707A have different edge
connectors, depending on the signal path configuration of
each card model. The multiplexer cards are summarized in
Table 3-2. All cards have a connector for the digital bus.
Note that rows A, B, C, and H of Model 7072 cards, for
example, are expanded with SMB coax jumpers between
adjacent cards to lessen signal losses of the low current and
C-V rows. The jumpers are internal to the mainframe.
When a mainframe contains different card models, instruments must be connected to each card type because of the
differing analog bus usage. An example of this is shown in
Figure 3-10.
Table 3-2
Matrix and multiplexer cards
Card family
Model
Form
Universal
7070
96 Open Collector Drivers
General
purpose
7071
7071-4
7074-D
7074-M
7075
7076
8 × 12 Matrix
Dual 4 × 12 Matrix Card
Eight 1 × 12 Multiplexer Card
Eight 1 × 12 Multiplexer Card
Eight 1 × 12 Multiplexer Card
Dual 4 × 12 Matrix Card
Semiconductor 7072
7072-HV
7172
7174
8 × 12 Matrix Card
8 × 12 Matrix Card
8 × 12 Matrix Card
8 × 12 Matrix Card
Coaxial
8 × 12 Matrix Card
8 × 12 Matrix Card
4× 12 Matrix Card
7073
7077
7173-50
3-13
Getting Started
Devices Under Test
1
A
External
Row
Connections H
12
13
24
A
7071
Slot 1
Instruments
Internal
Row
Connections H
25
A
7071
7072
Slot 2
Slot 3
H
36
37
A
Internal
Row
Connections H
48
49
60
A
7072
7073
Slot 4
Slot 5
H
A
Internal
Row
Connections H
61
72
7073
Slot 6
External
Row
Connections
External
Row
Connections
Figure 3-10
Row connection examples
In addition to expanding rows in a mainframe, it is also possible to isolate card rows to some extent. There are factoryinstalled jumpers on the backplane that can be removed to
separate the general purpose rows. These jumpers, which are
behind the Model 707A front panel, are between slots 3 and
4 of analog bus #1 and analog bus #2. Removing these jumpers effectively separates the mainframe into two 3-slot units.
(Jumper removal is described in paragraph 7.6.)
Another isolation method is simply to disconnect the SMB
coax jumpers between adjacent Model 7072 cards, for example. These jumpers (for rows A, B, G, and H) are accessed
through a door on top of the mainframe.
As an example, jumpers on the Model 7073 card let you
selectively expand rows on the backplane to slots on either or
both sides, or completely isolate rows from the backplane.
External expansion
External expansion within a single mainframe is possible
with user-installed wiring between rows and columns of like
cards. The available accessory cables for external connections are listed in Table 3-3.
3-14
CAUTION
Connecting dissimilar cards together
often degrades performance of both
cards. For example, connecting a Model
7072 to a Model 7073 would degrade
low current switching on the 7072 and
high frequency switching done with the
7073.
An example of external expansion uses the mainframe as one
6-slot unit and, for some applications, as two 3-slot units.
After removing the backplane jumpers, just use external row
jumpers between the cards in slots 3 and 4 to select the
desired configuration.
External expansion of the cards can also be used to implement a partial matrix. As shown in Figure 3-11 for Model
7071 cards, a column connection is made between the two
isolated general purpose backplanes. With the example connections shown, three crosspoints must be closed to source
(increasing the safety factor), but only one cross-point closure is needed to measure (recommended for sensitive
instruments).
Getting Started
Table 3-3
Model 707A external expansion cables
Model no.
Description
Expansion
7078-KIT
7078-MTC
Mass Terminated Cable Kit
Mass Terminated Cable (20 ft.)
7071, 7071-4 rows/columns,
7074 rows
7078-TRX-3
7078-TRX-10
3-lug Triax-Triax Cable (3 ft.)
3-lug Triax-Triax Cable (10 ft.)
7072, 7072-HV, 7172, 7174
rows/columns
7051-2
7051-5
BNC-BNC Cable (2 ft.)
BNC-BNC Cable (5 ft.)
7073, 7173-50 rows/columns
7074-KIT
7074-MTC
Mass Terminated Cable Kit
Mass Terminated Cable (20 ft.)
7074 banks
7075-MTC
Mass Terminated Cable (10 ft.)
7075, 7076 rows/columns
External Columns
(DUT's)
1
External Columns
(DUT's)
12
13
A
24
Backplane Row
Expansion Cable
7071
A
7071
Model 707A
Unit 1
A
7071
Model 707A
Unit 2
H
Backplane Row
Expansion Cable
External Rows
( Measure)
Model 707A
Unit 3
H
H
External
Columns
A
7071
External Rows
(Source)
Model 707A
Unit 4
H
Figure 3-11
Example of partial matrix expansion
3-15
Getting Started
3.5.2 Multiple unit expansion
Analog expansion
One method to expand a matrix across mainframe boundaries is to connect cards of separate stand-alone units, either
by rows or columns. Each unit has a different IEEE-488 bus
address and is programmed independently. The additional
digital I/O ports are available for programming.
The analog backplane buses can be expanded between separate mainframes. As seen in Figure 3-12, a mass terminated
cable can be used to extend Model 7071 card rows (J101J106, pins 23-86). This configuration of two stand-alone
units is an 8-row by 144-column general purpose matrix,
with each mainframe programmed independently.
As an example of expansion by columns, consider a 16-row
by 72-column matrix of Model 7072 cards. This can be done
by connecting all columns of card #1 in one unit to all columns of card #1 in another unit, and so on for all cards.
(Triax T-adapters are used in this example to connect instruments or devices to the columns.)
Analog expansion and control expansion
Another method of expanding a matrix with multiple mainframes is to connect up to five units in a master/slave configuration. This is done by connecting the rows of like cards in
separate units, as shown previously in Figure 3-12, but also
by connecting the units in a closed loop of DIN cables for
communication and control. A master/slave system configuration appears as one unit with expanded card capacity. That
is, only the master unit is addressed by the IEEE-488 bus
controller.
A master/slave configuration extends matrix rows yielding a
long, narrow matrix. Figure 3-13 shows the connections
between two units having Model 7071 cards. With five units,
the maximum matrix size is 8 rows by 360 columns. Figure
3-14 shows the column assignments for the maximum configuration.
If the mainframes of a master/slave configuration contain
different card models, group like cards as much as possible.
This will reduce the need to extend the analog buses with
external cables.
In some cases, external row expansion is not necessary at all
(e.g., one unit only with Model 7071 cards, the second unit
only with Model 7072 cards).
The example of Figure 3-15 shows the row expansion, but
not the closed loop of DIN cables for master/slave
communication and control. The figure shown is actually
three matrices (one 8-row by 72-column and two 8-row by
144-column) that are programmed as one 8-row by 360column matrix.
Columns
Columns
1
12
61
72
1
12
61
72
A
A
Rows
7071
7071
Slot 1
Slot 6
Rows
H
Rows
Unit 1
Figure 3-12
Model 7071 row connections of stand-alone units
3-16
Unit 2
7071
7071
Slot 1
Slot 6
Rows
H
Getting Started
Mass Terminated Cable
Master
(Columns 1 - 72)
Rows
Slave 1
(Columns 73 - 144)
Rows
M/S Out
M/S In
7071 7071 7071 7071 7071 7071
1
2
3
4
5
M/S Out
M/S In
7071 7071 7071 7071 7071 7071
Cols.
Cols.
6
1
2
3
4
5
6
To
Controller
Model 7007
IEEE Cable
Model 7078 - DIN Cables
Figure 3-13
Example of master/slave interconnect cables
3-17
Getting Started
Master
112
1
1324
2536
3748
4960
6172
2
3
4
5
6
Slave 1
7384
1
Slave 2
85- 97- 109- 121- 13396 108 120 132 144
2
3
4
5
6
145- 157- 169- 181- 193- 205156 168 180 192 204 216
1
2
Slave 3
2
3
Figure 3-14
Master/slave column locations
3-18
4
4
5
6
Slave 4
217- 229- 241- 253- 265- 277228 240 252 264 276 288
1
3
5
6
289- 301- 313- 325- 337- 349300 312 324 336 348 360
1
2
3
4
5
6
Getting Started
H
Columns
1
Columns
12
A
61
72
A
Instruments
7071
7071
Slot 1
Slot 6
Slots 2-5
Master
Master
H
H
Internal
Row
Connections
External
Row
Connections
Master (8 Rows by 72 Columns)
Columns
73
84
A
Columns
133
144
Columns
205
216
A
A
Instruments
Columns
145
156
A
7072
7072
7072
7072
Slot 1
Slot 6
Slot 1
Slot 6
Slave 1
Slave 2
Slot 2-5
Slave 1
H
H
External
Row
Connections
Slot 2-5
Slave 2
H
H
Internal
Row
Connections
Internal
Row
Connections
External
Row
Connections
Slaves 1 and 2 (8 Rows by 144 Columns)
Columns
Columns
217
228
A
227
289
Columns
300
A
A
Instruments
Columns
228
349
360
A
7073
7073
7073
7073
Slot 1
Slot 6
Slot 1
Slot 6
Slave 3
Slave 4
Slot 2-5
Slave 3
H
H
External
Row
Connections
Internal
Row
Connections
H
External
Row
Connections
Slot 2-5
Slave 4
H
Internal
Row
Connections
Slaves 3 and 4 (8 Rows by 144 Columns)
Figure 3-15
Example of master/slave row expansion
3-19
Getting Started
3.5.3 System expansion issues
Matrix expansion by Model 707A mainframes affects system specifications and speed. The extent depends on the size
and configuration of the switching system.
Within a mainframe, internal row expansion decreases isolation among like cards and increases offset current. Isolation
relays (on the Model 7072), backplane jumpers (for general
purpose rows), and SMB coax jumpers (on the Model 7072)
help lessen these effects.
Expansion of units along rows or columns also degrades the
isolation and offset current specifications because of the
number of parallel paths and relays on each signal line.
There are several issues that affect system speed, among
them are:
• Relay settling time — Each matrix card has a predefined relay settling time (for example 3msec for the
7071, 15msec for the 7072 and 7073). When card types
are mixed in a system, the longest settling time is in
effect.
• Bus communication — A master/slave setup responds
slower to bus commands because all communication is
through the master unit and the data transmission
among the units is verified with handshaking. Table 3-4
compares some typical times.
3-20
Table 3-4
Response time comparisons
Action
Stand-alone
Master with
4 slaves
Respond to bus command
to close single relay
<15ms
<55ms
Download one setup to
707A
60ms typical
—
3.5.4 Documenting system configuration
With the connection flexibility of the matrix topology and
the expansion/isolation options of the Model 707A, it is
important to document the system configuration.
An example table for tracking card connections and expansion is shown in Table 3-5. Use the top portion of the table to
note system operation and size, the FROM/TO portion to list
card row and column connections, and the lower portion for
notes concerning expansion and operation (e.g., make/break
and break/make rows).
Getting Started
Table 3-5
Model 707A card configuration
Slot: ___________________________________
Mainframe:
Model: _______________________
Stand-alone _________
Master _____________ Slave 1 _____________ Slave 2 _____________ Slave 3 _____________ Slave 4 ___________
System size:
_______________________ rows __________ columns ___________ IEEE address ___________
FROM
(Instrument connection or DUT pin)
External Card
Connection
TO
(Instrument connection or DUT pin)
Row A
B
C
D
E
F
G
H
Column 1
2
3
4
5
6
7
8
9
10
11
12
Expansion:
___ Backplane bus (rows through ribbon cable)
___ Point to point writing (rows/cols.)
___ BNC coax cable (rows/cols.)
___ SMB coax jumpers (rows)
___ Mass terminated cable (rows/cols.)
___ Triax cable (rows/cols.)
Notes:
3-21
Getting Started
3.6
Basic switching operation
The following paragraphs will take you through a simple,
general, step-by-step procedure to edit a matrix setup, store
it in memory, and send the setup to the relays. Although the
steps are described with front panel operations, the procedure can be performed over the IEEE-488 bus. (An example
program showing this is given in paragraph 5.2.) Even with
no instruments or DUTs connected to the matrix cards, the
procedure will still have instructional benefits.
3.6.2 Selecting make/break and break/make rows
Select make-before-break, break-before-make, or don’t care
operation for the rows. The selections will be in effect for all
relay switching, even if a stored setup is not used. (As a general rule, use make/break operation for current sources and
break/make for voltage sources.)
See Section 4 for more operation details including master/
slave configurations.
Use the data entry keys to select a row, then press MAKE/
BREAK or BREAK/MAKE to toggle the state. (Selecting
one state for a row de-selects it for the other.) This operation
can also be performed with the light pen by using it to turn
on/off the MAKE/BREAK and BREAK/MAKE LEDs.
3.6.1 Power-up
3.6.3 Modifying a relay setup
Check that the instrument is set to correspond to the available
line voltage. The line voltage switch is located on the rear
panel. If the switch is set to the correct position, connect the
instrument to a grounded AC outlet using the supplied power
cable and turn on the unit.
Perform the following steps to edit a matrix setup.
CAUTION
If the switch setting does not correspond
to the available line power, do not
change the switch setting and power up
the unit as the line fuse will probably
blow. Instead, proceed to paragraph 7.2
for the line voltage selection procedure.
Step 1: Select a stored setup
If you want to modify setup #1, just press the MEMORY key.
The MEMORY indicator will light. To select another setup
(up to location 100), use the numeric data entry keys
(1eading zeros are not necessary), then press the MEMORY
key.
Step 2: Modify the displayed setup
Use the data entry keys to select a crosspoint address (Al
through H72), then press the OPEN or CLOSE key. Keystrokes will be shown on the alphanumeric display and the
CROSSPOINT DISPLAY MODIFIED indicator will light.
The Model 707A will perform a powerup self-test to check
ROM, RAM, card configuration, stored setups, master/slave
loop, indicators, and displays. It will then display the software revision level and IEEE-488 bus address.
If you have the optional light pen, toggle the state of a
crosspoint LED by holding the light pen perpendicular to
and touching the front panel overlay and pressing the light
pen button.
When the self-test has completed, the Model 707A is configured with:
Continue editing with the front panel keys or light pen until
the crosspoint display shows the desired configuration.
• All relays opened.
• RELAYS indicator lit (crosspoint display shows current
relay setup).
• RELAY STEP to 000 (a pseudo setup memory that is
cleared at powerup and sent to the relays).
• MEMORY STEP to 001.
Other powerup defaults are detailed in paragraph 4.3.
3-22
Getting Started
3.6.4 Storing setup and sending to relays
Step 2A: Sending setup to relays
The following steps detail front panel operations necessary
to store and use the modified setup data.
To make the newly modified setup the current relay setup,
just press the COPY DISPLAY-RELAYS key. The relay
states will be changed to reflect the modified setup data. If
the MEMORY LED is lit, the RELAY STEP field will be set
equal to the MEMORY STEP field. In effect, this copies a
setup from memory to the relays.
Step 1: Storing setup in memory
To store the modified setup at the location shown in the
MEMORY STEP field, just press the COPY DISPLAYMEMORY key. This action overwrites the old setup data at
that location with the newly modified setup.
To select a different memory location, key in a valid location
number, then press the COPY DISPLAY-MEMORY key.
The MEMORY STEP field is set to the new location.
Step 2B: Triggering setup to relays
If you modified setup #1 and restored it to memory at the
same location, a single trigger will copy the setup to the
relays. Do this by pressing the trigger SOURCE key, scrolling to the “TRIG ON KEY” display and pressing ENTER.
Then press the trigger ENABLE key. Pressing the trigger
MANUAL key will copy setup #1 to the relays and set the
RELAY STEP field to 001.
3-23
4
Operation
4.1
Introduction
This section contains a complete, detailed description of
each front and rear panel aspect of the Model 707A. The section is arranged as follows:
4.2
Setup Data Paths: Describes the paths for setup data
within a Model 707A and to/from a bus controller.
4.3 Power-up Procedure: Details how to connect the
instrument to line power and turn it on, including
power-up self-test and default conditions.
4.4 Displays and Messages: Covers the uses of the
alphanumeric display, crosspoint display, and make/
break and break/make row LEDs. Also lists display
messages that may be encountered during front panel
operations.
4.5 Selecting Crosspoint Display: Describes how to
select the source of relay setup data (current relay
setup or a stored setup).
4.6 Modifying Crosspoint Display: Discusses the operations to open/close crosspoint display LEDs.
4.7 Copying Crosspoint Display: Describes copying a
display to the relays and to memory.
4.8 Inserting and Deleting Stored Setups: Covers how
to insert a blank setup in memory and how to delete a
stored setup from memory.
4.9 Menu Operations: Details menu item selection and
operation, including digital I/O, external trigger,
matrix ready, master/slave, IEEE-488 bus address,
relay settling time, card identification, self-test, and
factory defaults.
4.10 Selecting Switching Parameters: Covers the programmed settling time and make/break, break/make
operations.
4.11 Triggering: Details selecting the trigger source and
describes the operation of the rear panel trigger input
and output jacks.
4.12 Resetting: Discusses the reset operation of the Model
707A.
4.2
Setup data paths
The design of the Model 707A is optimized for high speed
switching of relay setups for matrices with a maximum of 8
rows by 72 columns (one unit) to 8 rows by 360 columns
(five units). If no rows are selected for make/break or break/
make operation, previously stored setups can be switched to
the relays at a rate of up to 200 setups per second.
Besides the triggering of stored setup data to the relays, setup
data can be routed to/from the sources and destinations
shown in Figure 4-1. The data paths are selected by the front
panel or IEEE-488 bus operations listed in Table 4-1.
Crosspoint
Display
Current
Relay Setup
100 Stored
Setups
Model 707
Controller
IEEE-488 Bus
Controller
Figure 4-1
Paths for relay setup data
In addition to other front and rear panel operations, this section describes setup data transfers that are performed from
the Model 707A front panel. Section 5 will describe the bus
operations that transfer setup data.
4-1
Operation
Table 4-1
Setup data paths
Setup data path
Action required
Display-Memory Display- Front panel keystroke Front
Relays
panel keystroke or an automatic copy (Note 1)
Memory-Display
Front panel keystroke or an
automatic operation (Note 2)
Memory-Relays
Bus command or any valid
trigger
Bus command
Memory-Controller
Memory-Memory
Bus command
Relays-Display
Front panel keystroke or an
automatic operation (Note 3)
Relays - Memory
Bus command
Relays-Controller
Bus command
Controller-Memory
Bus command
Controller-Relays
Bus command
Notes:
1. Generation of the automatic copy is selected by a front panel key.
(AUTOMATIC LED is lit.)
2. The automatic operation is generated if the displayed setup has been
changed by a bus command and has not been modified from the front
panel. (MEMORY LED is lit.)
3. The automatic operation is generated if the displayed setup has been
changed by a trigger or bus command and has not been modified
from the front panel. (RELAYS LED is lit.)
4. Controller modifications to setups are reflected on the crosspoint display if the affected setup is currently being displayed.
5. Front panel keystrokes can be generated by bus commands.
4.3
Power-up procedure
The steps in the following paragraphs take you through the
basic procedures for selecting the line voltage, connecting
the instrument to line power, and turning on the instrument.
4.3.1 Line voltage selection
The Model 707A operates from a line voltage in the range of
100 to 240V, at a frequency of 50 or 60Hz. Line voltage and
frequency are automatically sensed, therefore there are no
switches to set. Check to see that the line power in your area
is compatible.
4.3.2 Line power connections
Using the supplied power cord, connect the instrument to an
appropriate 50 or 60Hz ac power source. The female end of
the cord connects to the ac receptacle on the rear panel of the
instrument. The other end of the cord should be connected to
a grounded ac outlet.
4-2
WARNING
The Model 707A must be connected to a
grounded outlet to maintain continued
protection against possible shock hazards. Failure to use a grounded outlet
may result in personal injury or death
due to electric shock.
4.3.3 Power switch
To turn on the power, simply push in the front panel POWER
switch. Power is on when the switch is at the inner (1) position. To turn power off, press POWER a second time.
4.3.4 Power-up self-test and messages
During the power-up cycle, the instrument performs the following tests. The first five operations are transparent to the
user unless an error occurs.
1. A checksum test is performed on ROM and a read/write
test on RAM. If an error is found, the self-test continues
and the unit displays either ROM FAIL or RAM FAlL
when the test has completed. You can override either
type of error with a front panel keypress. The Model
707A will attempt normal operation.
NOTE
If a problem develops while the
instrument is still under warranty (1ess
than one year from shipment date), return
it to Keithley Instruments, Inc. for repair.
For units out of warranty refer to Section
6, Maintenance.
2. The Model 707A reads identity information from each
card and performs a checksum test on the data. If the
checksum test fails on one or more matrix cards, the
instrument displays CARD ID ERROR and lights all
crosspoint LEDs of that card. Any keypress will allow
the unit to continue. An empty slot will not produce an
error.
3. A checksum test is performed on all setups in memory.
If the instrument detects a checksum error in one or
more stored setups, it displays the message SETUP
ERROR and clears the crosspoints bits of the setup(s) in
error. The message remains displayed until a key is
pressed.
NOTE
The SETUP ERROR message may be an
indication of a low battery. Cycle power
off and on. If the message reappears, see
paragraph 7.7 for battery replacement
procedure.
Operation
4. The present card configuration (i.e., which cards are installed in which slots) is compared with the unit's previous configuration. If there is a change, the 100 setups in
memory are reformatted. (The front panel display is
blanked out during this time.) Crosspoint closures are
not affected, just the way a setup is stored for the different cards.
5. If the unit was previously programmed as a stand-alone
or slave unit, it powers up as a stand-alone. If the unit
was programmed as a master the last time it was on, it
checks for additional units in a serial looped configuration and tries to make them slave units. (Refer to paragraph 4.3.6 for information concerning turning on a
master/slave configuration.)
The message M/S ERROR is displayed if there is not a
closed loop (the Model 707A can be looped back to itself). Any keypress or IEEE-488 bus operation will allow the unit to continue as a stand-alone unit.
6. The instrument performs the display test, where it lights
all segments of the alphanumeric display, all crosspoint
LEDs, and all other LED indicators. Then it briefly displays the software revision level and the programmed
primary IEEE-488 address as in this example:
Knowing the software revision level is useful when discussing problems with Keithley Instruments. In this example, the factory default primary IEEE-488 address is
displayed. The actual address depends on the programmed value.
4.3.5 Power-up configuration
After the power-up tests and display messages are completed, the Model 707A assumes specific operating states:
• All relays are opened.
• The RELAYS indicator is lit (crosspoint display shows
current relay setup).
• The RELAY STEP field is set to 000 and the MEMORY
STEP field is set to 001.
• Trigger disabled.
Table 4-2 summarizes the power-up configuration for the
unit. The entire power-up process takes approximately five
seconds to complete.
A01 IEEE 18
Table 4-2
Power-up, reset, and factory defaults
Parameter
Relays
Stored setups
RELAY STEP
MEMORY STEP
Digital output
External trigger
Matrix ready
Master/slave
IEEE-488 address
Programmed settling time
Make/break rows
Break/make rows
Trigger enable
Trigger source
Power-up/reset
default
All opened
Unchanged
000
001
000
Falling edge
Active low
Unchanged
(if successful)
Unchanged
0msec
Unchanged
Unchanged
Disabled
External
Factory default
All opened
All cleared
000
001
000
Falling edge
Active low
Unchanged
18
0msec
None selected
None selected
Disabled
External
4-3
Operation
4.3.6 Master/slave power-up
The power-up sequence for Model 707A mainframes can be
summarized as follows:
power before initializing. Thus, it is not necessary to turn on
the master unit last.
CAUTION
When it is necessary to cycle power on a
slave unit, turn off all units in the
master/slave configuration. This procedure prevents the open communication and control loop from putting the
slave unit in an undesirable state.
Each unit connected in the master/slave loop displays M/S
LOOP DOWN until all units are powered up.
• Units previously programmed as stand-alones or slaves
power up as stand-alones.
• A unit previously programmed as a master powers up as
a master and tries to initiate a loop connection. If it is
successful, other units in the loop become slaves. If it is
not successful, the message M/S ERROR is displayed
and the unit reverts to stand-alone operation.
To connect and power up a master/slave configuration for the
first time, follow these steps:
1. Connect up to five mainframes in a daisy chain (Master/
Slave Out of one unit to Master/Slave In of next unit) as
previously shown in Figure 3-14 for two units.
2. Power up each unit. Since there is no master in the loop
as yet, all units will power up as stand-alones. The units
will display the message M/S LOOP DOWN until all
are turned on.
3. From the front panel of the desired master unit, press the
MENU key until the alphanumeric display shows:
4.4
Displays and messages
4.4.1 Alphanumeric display
The alphanumeric display is a 14-character display that can
show error messages, informational messages (e.g., menu
item parameters), last setup sent to relays, last setup recalled
to crosspoint display, trigger source, programmed settling
time, and alphanumeric key presses. See Figure 4-2.
The 3-digit RELAY STEP field of the alphanumeric display
shows the location of the last setup sent from memory to the
relays. A trigger causes the next setup (RELAY STEP +1) to
be sent to the relays.
STANDALONE
Press one of the SCROLL keys to change the display to
MASTER, then press ENTER. This action initiates a loop
connection, making this unit the master and the other units
slaves, and exits menu mode.
During subsequent power-ups of master/slave configurations, all connected mainframes wait for all units to get
KEITHLEY
The 3-digit MEMORY STEP field of the alphanumeric display shows the location of the last setup recalled from memory to the crosspoint display.
The 6-digit data entry scratchpad field reflects alphanumeric
key presses by the user, such as row and column addresses
and setup locations.
707A SWITCHING MATRIX
TALK
LISTEN
REMOTE
RELAY STEP
Figure 4-2
Alphanumeric display
4-4
MEMORY STEP
Operation
4.4.2 Display messages
During Model 707A operation and programming, you will
encounter a number of front panel messages on the alphanumeric display. Typical messages will be either of error or
informational variety, as discussed in the following paragraphs.
Error Messages
Error messages are divided into two categories: those which
stay on the display until a keypress or some other operation
changes the display, and those which appear for two seconds
and then the display returns to its previous state.
Table 4-3 lists Model 707A error messages. Many of these
messages are also covered in pertinent paragraphs of the
manual. Where applicable, the necessary corrective action is
also given in the table.
Informational messages
Informational messages are included as a programming aid.
No corrective action is necessary, but you still may be
required to enter a parameter at the prompt. Table 4-4 lists
Model 707A informational messages. Again, most of these
are covered in other parts of the manual.
Table 4-3
Error messages
Message
Description
Corrective Action
CARD ID ERROR* Checksum test failed on one or more matrix cards. Remove card identified by all crosspoint LEDs
lit.
IDDC
Invalid device-dependent command.
Send only valid commands (see Section 5).
IDDCO
Invalid device-dependent command option.
Send only valid command options (see
Section 5).
INVALID INPUT
Invalid crosspoint address, setup location, make/
Enter valid data.
break or break/make row, or parameter out of
range.
LIGHT PEN????
Light pen button pressed when pen was not pointed Press button with pen perpendicular to LED.
at crosspoint LED or make/ break or break/make
LED.
Check for a closed loop of MASTER/SLAVE
M/S ERROR*
Error in master/slave communication loop (overOUT to MASTER/SLAVE IN.
run, parity, framing, count imbalance, or time-out).
M/S LOOP DOWN One or more units connected in master/slave loop Turn on all units or reconfigure master/slave loop.
are not powered up.
Put Model 707A in remote.
NOT IN REMOTE “X” character received over IEEE-488 bus but
Model 707A is not in remote.
See troubleshooting in Section 7.
RAM FAIL*
Self-test detected error in RAM.
See troubleshooting in Section 7.
ROM FAIL*
Self-test detected checksum error in ROM.
Affected setup is cleared, then Model 707A proSETUP ERROR*
Self-test detected checksum error in stored setup. ceeds normally.
Battery may be low.
Check the READY bit in the serial poll byte.
TRIG OVERRUN
An additional trigger was received before the
Model 707A asserts the READY signal.
* Message remains displayed until next operation.
4-5
Operation
Table 4-4
Information messages
Message
Key(s)
Description
IN 255 OUT 000
MENU
EXT TRIG FALL
EXT TRIG RISE
MENU
MENU
Digital input status and digital output parameter
(decimal values).
Falling edge external trigger pulse.
Rising edge external trigger pulse.
MATRIX RDY LO
MATRIX RDY HI
STANDALONE
MASTER
IEEE-488 18
HWSETL 015 mS
MENU
MENU
MENU
MENU
MENU
MENU
Matrix Ready pulse active low.
Matrix Ready pulse active high.
Stand-alone operation of Model 707A.
Master unit in master/slave configuration.
IEEE-488 bus address of 18.
Longest relay settling time of present card configuration (Model 7073 is shown).
1 7071
MENU
SELF TEST
FACTORY INIT
SETL 00000 mS
MENU
MENU
SETTLING TIME
TRIG ON EXT
TRIG ON KEY
TRIG ON TALK
TRIG ON GET
TRIG ON X
NOT SETTLED
SOURCE
SOURCE
SOURCE
SOURCE
SOURCE
—
Card configuration by slot and model number
(Model 7071 in slot 1 is shown).
Item to select self-test execution.
Item to select factory defaults (setups cleared).
Programmed settling time (added to relay settling time).
External trigger pulse triggering.
Front panel key triggering.
IEEE talk command triggering.
IEEE GET command triggering.
IEEE X command triggering.
Additional trigger received before programmed
settling time expired (trigger is processed).
4.4.3 IEEE-488 status indicators
4.4.4 Crosspoint display LEDs
The TALK, LISTEN, and REMOTE LEDs (shown in Figure
4-2) indicate these modes when the Model 707A is being
programmed over the IEEE-488 bus. The TALK and LISTEN indicators show when the unit has been addressed to
talk or listen. These talk and listen commands are derived
from the unit’s primary address. REMOTE turns on to show
when the unit is placed in remote by addressing it to listen
with the REN line true. (All front panel controls except
LOCAL and POWER are inoperative when REMOTE is on.)
Local operation is restored by pressing LOCAL unless the
IEEE-488 LLO (Local Lockout) command is in effect. See
Section 5 for details of IEEE-488 bus operation.
As shown in Figure 4-3, the crosspoint display has six blocks
of LEDs (one per card slot). Each block has 8 rows (A-H)
by12 columns (1-12, 13-24, etc.) of LEDs. The display LEDs
can show the current open/closed relay states, the on/off
states of a setup from in memory, or the on/off states of a
setup currently being edited. The on/off states of crosspoint
LEDs can be changed by front panel keys, commands over
the bus, or an optional light pen. Modified displays can be
stored in memory or sent to the relays.
4-6
Operation
Figure 4-3
Crosspoint display
4-7
Operation
4.4.5 Make/break and break/make LEDs
4.4.6 Light pen
The MAKE/BREAK and BREAK/MAKE displays each
have two blocks of LEDs labeled A-H (one for columns
1-36, the other for columns 37-72). Refer to Figure 4-3. Each
block shows which rows have been selected for make/break
or break/make operation. When switching current sources,
use make/break operation to keep current flowing and eliminate switching transients. When switching voltage sources,
use break/make operation to avoid momentary shorting of
two paths together.
The light pen is an optional input device for toggling the on/
off states of crosspoint display LEDs, MAKE/BREAK row
LEDs, and BREAK/MAKE row LEDs. One light pen is used
to control the LEDs of all units in a master/slave system.
The LEDs can be turned on or off by pressing a row letter key
and the MAKE/BREAK or BREAK/MAKE key, or with an
optional light pen. Note that selecting a row for break/make
de-selects it for make/break and vice versa.
4-8
As seen in Figure 4-4, the light pen plugs into the front panel
of stand-alone or master units. Remove the light pen by
pressing the button on the connector plug while pulling out
the plug. Mount the light pen holder on the left handle of the
Model 707A by tightening the allen-head screw shown in
Figure 4-4.
To toggle the state of a crosspoint LED or MAKE/BREAK,
BREAK/MAKE LED with the light pen, follow these steps:
1. Hold the light pen as you would an ordinary pen.
2. With the light pen perpendicular to the front panel
overlay at the desired LED, press the button on the pen's
barrel.
3. Proper usage will toggle the state of the LED. If the button is pressed while not on an LED, the message LIGHT
PEN???? is displayed briefly, then the Model 707A
reverts to its previous display.
Operation
Figure 4-4
Light pen
4-9
Operation
4.5
Selecting crosspoint display
In the CROSSPOINT DISPLAY key group on the front
panel are two keys that are used to bring setups to the crosspoint display. See Figure 4-5. Three LEDs in the group indicate the source of setup data. Only one of these LEDs is lit at
a time:
• MEMORY LED — When lit, the crosspoint display
shows a setup stored in memory.
• RELAYS LED — When lit, the crosspoint display
shows the current relay setup.
• CROSSPOINT DISPLAY MODIFIED LED — When
lit, the crosspoint display shows a modified setup that
was previously from memory or from the relays.
CROSSPOINT DISPLAY
MEMORY
RELAY S
CROSSPOINT
DISPLAY
MODIFIED
DISPLAY
DISPLAY
COPY
MEMORY
COPY
MEMORY
AUTOMATIC
Figure 4-5
Crosspoint display keys
Pressing the MEMORY key displays a stored relay setup
(location shown in MEMORY STEP field) on the crosspoint
display and lights the MEMORY indicator. If a valid location
(1400) is entered first from the data entry keypad, that setup
is displayed on the crosspoints and in the MEMORY STEP
field. (The INVALID INPUT message is displayed briefly
for locations out of range.) The CANCEL key can be used to
remove incorrect entries from the alphanumeric display.
When the MEMORY indicator is lit, a setup can also be displayed by entering a valid location and pressing ENTER, or
by pressing a SCROLL key to display the setup at MEMORY STEP ±1. If you press and hold a SCROLL key, the
MEMORY STEP field is updated continuously. As location
000 is invalid for MEMORY STEP, the SCROLL keys skip
this location when incrementing or decrementing.
If the displayed setup is modified by IEEE-488 commands,
the crosspoint display changes if the MEMORY indicator is
lit. In other words, if you are editing a setup, changes to its
source do not appear.
Pressing the RELAYS key displays the current relay setup on
the crosspoint display and lights the RELAYS indicator. If a
valid location (0400) is entered first, that setup is sent to the
relays and displayed on the crosspoints and in the RELAY
STEP field. When location 000 is selected in this manner, the
relay states do not change.
When the RELAYS indicator is lit, a setup can also be sent
to the relays and displayed by entering a valid location and
pressing ENTER, or by pressing a SCROLL key to send and
display the setup at RELAY STEP ±1. If you press and hold
a SCROLL key, the RELAY STEP field is updated continuously. As the SCROLL keys increment and decrement the
RELAY STEP field through location 000, there is no effect
on the relays. That is, when the RELAY STEP is decremented from 001 to 000, or when incremented from 100 to
000, the relays do not change state.
If the relays change due to a trigger or IEEE-488 commands,
the crosspoint display changes only if the RELAYS indicator
is lit.
4.6
Modifying crosspoint display
After choosing the source of the setup, a crosspoint display
can be modified by turning on/off crosspoint LEDs with
front panel keys or the light pen. As discussed in the next
paragraph, if the AUTOMATIC (COPY DISPLAY→
RELAYS) indicator is lit, these actions open/close relays
immediately.
The alphabetic data entry keys (A-H) are for entering the row
part of a crosspoint address. The numeric keys (0-9) are for
entering column numbers. Use the CANCEL key to remove
incorrect entries from the alphanumeric display. Refer to
Figure 4-6.
4-10
Operation
G
H
7
8
9
E
F
4
5
6
C
D
1
2
3
A
B
0
CANCEL
ENTER
Figure 4-6
Data entry keys
The maximum valid column number with a single unit is 72.
If several mainframes are connected and programmed for
master/slave operation, the maximum column can be up to
360 (with five units).
When a valid crosspoint address (row and column) is in the
alphanumeric display, pressing the OPEN key turns off the
crosspoint display LED. (The message INVALID INPUT is
displayed for addresses out of range.) If the AUTOMATIC
(COPY DISPLAY → RELAYS) indicator is lit, the corresponding relay opens immediately. The CLOSE key performs the same action as the OPEN key except that it turns
on crosspoint display LEDs and relays.
Pressing the CLEAR key turns off all crosspoint display
LEDs. If the AUTOMATIC (COPY DISPLAY → RELAYS)
indicator is lit, all relays are opened immediately.
The CROSSPOINT DISPLAY MODIFIED indicator lights
and the MEMORY or RELAYS indicator go out when
changes are made to the crosspoint display, making it different from the configuration of its source. It also lights when
opening an already open crosspoint and closing an already
closed crosspoint. The SCROLL keys are not active when the
CROSSPOINT DISPLAY MODIFIED indicator is lit.
The optional light pen can also be used to turn on and off
crosspoint LEDs. Just hold it perpendicular to the front panel
overlay at the desired LED and press the button on its barrel.
This action toggles the state of the LED.
The maximum number of simultaneously closed crosspoints depends on the specified drive current per crosspoint
of each card. The total relay drive current required per mainframe cannot exceed 48.5A, since the 6V/50A power supply
also provides 1.5A for the front panel display.
4.7
Copying crosspoint display
The setup data displayed on the crosspoint LEDs can be
stored in non-volatile memory of the Model 707A or can be
sent directly to the relays by pressing either the COPY DISPLAY → MEMORY or the COPY DISPLAY → RELAYS
key, seen previously in Figure 4-5.
With the COPY DISPLAY → MEMORY key, the displayed
crosspoint configuration is stored at the setup location shown
in MEMORY STEP field. It overwrites the present setup data
at that location. If a valid location is keyed in first, pressing
this key stores the crosspoint configuration at that setup and
sets the MEMORY STEP field to that location. If the
CROSSPOINT DISPLAY MODIFIED indicator is lit, it
goes out and the MEMORY LED lights. The INVALID
INPUT message is displayed briefly if you try to copy to a
setup location below one or above 100.
In master/slave configurations, each unit stores its own portion of each stored setup.
When the COPY DISPLAY → RELAYS key is pressed, the
displayed crosspoint configuration is sent to the relays:
• If the MEMORY indicator is lit (i.e., the crosspoint display shows an unmodified setup from memory), the
RELAY STEP field is set to the MEMORY STEP field.
In effect, this copies a setup from memory to the relays.
• If the RELAYS indicator is lit, the RELAY STEP field
is not affected, as it reflects the last stored setup sent to
the relays.
• If CROSSPOINT DISPLAY MODIFIED is lit, it goes
out and the RELAYS LED lights.
4-11
Operation
Copying the crosspoint display to the relays can be performed automatically with the toggle-action AUTOMATIC
(COPY DISPLAY → RELAYS) key. When the AUTOMATIC indicator is lit, any change to the crosspoint display
is also sent to the relays at the same time. This action is
apparent when scrolling through unmodified stored setups,
as the MEMORY STEP and RELAY STEP fields will
sequence together. Changes to the crosspoint display while
the AUTOMATIC LED and RELAY LEDs are lit cause the
CROSSPOINT DISPLAY MODIFIED LED to blink and the
RELAYS LED to remain lit.
If a valid location is keyed in first, the MEMORY STEP field
is set there and then the insert operation takes place.
Pressing the DELETE key removes the stored setup at the
location shown in the MEMORY STEP field. While the
delete is taking place, the alphanumeric display is blank. All
setups higher than the selected setup are moved down one
location. (Setup 100 is cleared.) After the delete operation,
the crosspoint LEDs display the new setup “nnn”, which previously was setup “nnn+1”.
If a valid location is keyed in first, the MEMORY STEP field
is set there and then the deletion takes place.
4.8
Inserting and deleting stored setups
The two keys in the MEMORY group (see Figure 4-7) operate on setups stored in Model 707A memory. These keys are
active only when the MEMORY LED is lit.
In master/slave configurations, the insert blank setup and
delete stored setup operations perform similarly, except on
all units of the system.
4.9
MEMORY
INSERT
DELETE
Figure 4-7
Memory keys
Use the INSERT key to place a blank setup at the memory
location shown in the MEMORY STEP field. While the
insert is taking place, the alphanumeric display is blank. All
setups from the selected setup through 99 are moved up one
location. (Setup 100 is deleted by overwriting it with setup
99.) After the insert operation, the crosspoint LEDs display
a blank setup.
4-12
Menu operations
The Model 707A has several operations that are performed
by front panel menu items. Select the first item by pressing
the MENU key, subsequent presses of MENU display the
remaining items (see Table 4-5). To view all current menu
selections just press and hold the MENU key.
Status items are displayed with no user action. Numeric
items are modified by keying in the desired value with the
data entry keys and pressing ENTER. Multiple choice items
are selected by scrolling through the choices until the desired
one is displayed, then pressing ENTER. Immediate action
items are invoked by pressing ENTER.
If no modifications are made with the SCROLL or data entry
keys, pressing CANCEL exits from the menu without changing any values; otherwise CANCEL restores the current
value of the parameter. Pressing ENTER exits from the menu
(with changes), except when programming the digital output
status.
Operation
Table 4-5
Menu operations
Message
Item Description
Type
IN iii OUT 000
View digital input, program digital output.
status/numeric
EXT TRIG FALL
EXT TRIG RISE
Select which edge of external trigger pulse triggers Model 707A (falling
or rising).
multiple choice
MATRIX RDY LO
MATRIX RDY HI
Select matrix ready output level (active LO or HI).
multiple choice
STANDALONE
MASTER
Select stand-alone or master/slave operation.
multiple choice
IEEE-488 nn
Program IEEE-488 bus address.
numeric
HWSETL nnn mS
View longest relay (hardware) settling time of cards in system.
status
n cccc
View slot number (n) and card label (cccc).
status
SELF TEST
Execute self test.
immediate action
FACTORY INIT
Return to factory defaults. (All stored setups are cleared.)
immediate action
4-13
Operation
4.9.1 Digital I/O
The TTL-compatible DIGITAL I/O port has eight data lines
for inputs, eight data lines for outputs, and two control lines
for handshaking. The pinout for the rear panel DB-25 connector is shown in Figure 4-8. Status of the input lines is
viewed and states of the output lines are programmed
through the first menu item. With no input connections and
power-up default conditions for the output, the alphanumeric
display will read the following decimal values:
IN 255 OUT 000
The digital inputs are logic high with no connections. Use
the control line INLATCH (low true) to latch in the digital
inputs when changing an input state.
To program the digital output states, select the desired decimal value with the data entry keys and press ENTER. You
can now key in another value and press ENTER, or press
CANCEL to exit menu mode, or press MENU to continue to
the next item. Each time the digital outputs are programmed,
even if the states are not changed, the control line OUTPULSE is brought low.
With master/slave configurations, only the DIGITAL I/O
port of the master unit is available for viewing and
programming.
GND
OUT7
24
OUT6
23
OUT5
22
OUT4
21
OUT3
20
OUT2
19
OUT1
18
OUT0
17
GND
16
OUTPULSE
15
GND
Figure 4-8
Digital I/O port
4-14
13
NO CONNECTION
12
GND
11
IN7
10
IN6
9
IN5
8
IN4
7
IN3
6
IN2
5
IN1
4
IN0
3
GND
2
INLATCH
1
GND
25
14
16
4.9.2 External trigger
If triggers are enabled, and external trigger is selected as a
source, a TTL-compatible pulse of at least 600nsec duration
at the rear panel EXTERNAL TRIGGER INPUT jack triggers the Model 707A. The input BNC jack is shown in Figure
4-9.
EXTERNAL
TRIGGER
INPUT
MATRIX
READY
OUTPUT
Figure 4-9
Rear panel BNC jacks
The unit can be programmed with a menu item for which
edge (falling or rising) of the external trigger pulse causes a
transfer of stored setup data to the relays. Sample trigger
pulses are shown in Figure 4-10. To select which pulse edge
triggers, use the MENU key to choose the menu item for
external trigger. The power-up default display will read:
EXT TRIG FALL
Operation
Falling
Edge
4.9.3 Matrix ready
The Model 707A provides a TTL-compatible signal at its
rear panel MATRIX READY OUTPUT jack. The output
BNC jack was shown in Figure 4-9. The MATRIX READY
signal goes false when relays are switched and goes true at
the end of the programmed settling time. (As described in
paragraph 4.11, this is also after the relay settling time.)
TTL High
(3.4V Typical )
TTL Low
( 0.25V Typical )
600nsec
Minimum
A. Falling edge of pulse
Through a menu item, the unit can be programmed for a
high- or low-true MATRIX READY signal, as seen in Figure
4-11. To select the active state of the signal, press the MENU
key until the MATRIX RDY item is displayed. The power-up
default display will read:
Rising
Edge
TTL High
(3.4V Typical )
MATRIX RDY LO
TTL High
( 3.4V Typical )
TTL Low
( 0.25V Typical )
600nsec
Minimum
TTL Low
( 0.25V Typical )
A. Matrix ready high true
B. Rising edge of pulse
Figure 4-10
Sample external trigger pulses
Relay Settling Time +
Programmed Settling Time
TTL High
(3.4V Typical )
To choose the alternate external trigger state, use the
SCROLL
or
keys, then press ENTER. This action
also exits from the menu mode. (Pressing CANCEL instead
of ENTER returns external trigger to its previous state and
the Model 707A remains in menu mode.)
In master/slave configurations, only the EXTERNAL TRIGGER INPUT port of the master unit is active.
See paragraph 4.11 for more information on triggering the
Model 707A.
TTL Low
( 0.25V Typical )
Relay Settling Time +
Programmed Settling Time
B. Matrix ready low true
Figure 4-11
Sample matrix ready pulses
To choose the other active state, use the SCROLL
or
keys, then press ENTER. This action also exits from the
menu mode. (Pressing CANCEL instead of ENTER returns
matrix ready to its previous state and the Model 707A
remains in menu mode.)
In master/slave configurations, the MATRIX READY signals of all units function, but only that of the master is to be
considered accurate.
4-15
Operation
4.9.4 Stand-alone and master/slave
One method to expand system size is to connect up to five
mainframes in a master/slave configuration, where all units
are daisy-chained for serial communication and control. System operations are performed through the master unit, either
over the IEEE-488 bus or the master's front panel (including
the light pen). A master/slave system appears as a single unit
(and IEEE-488 address) with a maximum size of 8 rows by
360 columns. Selection of stand-alone or master/slave operation is done with a menu item.
As previously described in paragraph 3.5, the MASTER/
SLAVE OUT and MASTER/SLAVE IN rear panel connectors are used to connect DIN cables in a closed loop. The
connector pinouts are defined in Figure 4-12.
This action is performed by pressing the MENU key of the
desired master mainframe until the display reads STAND
ALONE. Next, scroll up or down to the MASTER message.
Then, press the ENTER key to initiate the master/slave loop.
If the loop is complete (MASTER/SLAVE OUT to MASTER/SLAVE IN in a daisy chain among all units), the master
unit will exit menu mode and the other units will display
SLAVE 1, SLAVE 2, etc. (The slave number is determined
by the unit's position in the loop.) If the loop of DIN cables
is not closed, the master will display the message M/S
ERROR and all units will remain as stand-alones.
When the units are powered up one at a time, they will
display the message M/S LOOP DOWN until all units are
powered.
CAUTION
When it is necessary to cycle power on a
slave unit, turn off all units in the
master/slave configuration. This procedure prevents the open communication and control loop from putting the
slave unit in an undesirable state.
7
8
6
5
3
4
AAAAAA
AAA
A
2
Pin
1
2
3
4
5
6-8
1
During master/slave operation, most front and rear panel
controls of the slave units are inactive. Table 4-6 shows
which controls and indicators remain active for slave units.
Master/Slave IN
Master/Slave Out
M/S TRIGGER (low true)
ALLREADY
LPRESET (low true)
LPSENSE (low true)
RxDATA
Chassis Ground
M/S TRIGGER (low true)
ALLREADY
LPRESET (low true)
LPSENSE (low true)
TxDATA
Chassis Ground
Figure 4-12
Master/slave connectors
After interconnecting and powering up all units, one unit is
selected to be a master.
4-16
The master unit communicates with the slaves only when
necessary; it does not continuously monitor the status of the
closed-loop configuration. Hence, a disconnected master/
slave loop cable is not detected, and the message M/S
ERROR is not displayed, until the master attempts to send or
receive data around the loop. The steps taken by a master unit
to recover from an M/S ERROR are outlined below:
1. The master stops processing IEEE-488 bus commands,
returns to stand-alone operation, and disables.
2. The slave units remain the same as before the error
occurred.
3. To re-initialize the loop, ensure that master/slave cables
are secure, and select master/slave operations from the
mainframe that previously was master.
Operation
4.9.5 IEEE-488 bus address
Control, indicator, or connector
Status
POWER
CROSSPOINT DISPLAY Group:
MEMORY key and LED
RELAYS key and LED
CROSSPOINT DISPLAY
MODIFIED LED
COPY DISPLAY — MEMORY
COPY DISPLAY — RELAYS
AUTOMATIC key and LED
SCROLL
and SCROLL
MEMORY Group:
INSERT
DELETE
MENU key and LED
SWITCHING Group:
SETTLING TIME
MAKE/BREAK
BREAK/MAKE
LOCAL
TRIGGER Group:
ENABLE key and LED
SOURCE
MANUAL
Data Entry (A-H, 0-9)
CANCEL, ENTER
RESET
CLEAR, OPEN, CLOSE
Alphanumeric Display
TALK, LISTEN, REMOTE LEDs
Crosspoint Display LEDs
MAKE/BREAK and BREAK/MAKE
Row LEDs
LIGHT PEN
active
Rear Panel Connectors:
MASTER/SLAVE IN
MASTER/SLAVE OUT
EXTERNAL TRIGGER INPUT
MATRIX READY OUTPUT
REALY TEST
DIGITAL I/O
IEEE-488 INTERFACE
Notes:
1. Messages only.
2. Timing accuracy not guaranteed.
3. Outputs set to all low.
only LED active
only LED active
active
The Model 707A communicates over the IEEE-488 bus
through the rear panel connection shown in Figure 4-13.
When connected to a bus controller, instrument operating
modes can be programmed. Note that IEEE-488 common is
always grounded. IEEE-488 interface function codes are
marked adjacent to the connector.
inactive
inactive
only LED active
inactive
SH1
AH1
T6
TE0
L4
LE0
SR1
RL1
PP0
DC1
DT1
E1
C0
inactive
inactive
inactive
inactive
inactive
inactive
inactive
only LED active
inactive
inactive
inactive
inactive
inactive
inactive
active (Note 1)
inactive
active
active
inactive
active
active
inactive
active (Note 2)
not used
inactive (Note 3)
not used
IEEE-488 INTERFACE
Table 4-1
Status of slave unit controls
Figure 4-13
IEEE-488 bus connector
A menu item is used to set the primary address of the Model
707A for bus operation. The primary address of the Model
707A is factory set to 18, but it may be set to any value
between 0 and 30 as long as address conflicts with other
instruments or the bus controller are avoided.
To check the present primary address or to change to a new
one, perform the following procedure:
1. Press the MENU key until the current primary address
is displayed. For example, if the instrument is set to primary address 18, the following message is displayed:
IEEE-488 18
2. Press CANCEL to retain the present address and exit
menu mode.
3. To change the primary address, use the data entry keys
to key in a new value, then press ENTER. This action
will also exit menu mode. The new address will be
stored in memory so that the instrument powers up to
that address.
4-17
Operation
NOTE
4.9.8 Self-test
Each device on the bus must have a unique
primary address. Failure to observe this
precaution will probably result in erratic
bus operation.
The self-test program is intended to check ROM, RAM, and
the front panel LED indicators. This test is also part of the
power-up sequence. If you want to run the test without
cycling power, use the following procedure to select and run
it:
Section 5 contains detailed information on operating the
Model 707A over the IEEE-488.
1. Press the menu key until the display reads SELF TEST.
2. Press the ENTER key to initiate the test. The unit's ROM
and RAM are checked. Next, all the front panel LEDs
are lit for your inspection. If no errors are detected,
menu mode is exited.
4.9.6 Relay (hardware) settling times
The card specification “relay settling time” is the time
needed for the relays to actuate or release (including contact
bounce time) and pass a clean signal. Since this specification
is card dependent, the Model 707A must identify on powerup which cards are installed to determine the longest relay
settling time in the system (stand-alone or master/slave).
This value is not user-modified, but the total settling time for
a switching operation can be lengthened by using the programmed settling time, as explained in paragraph 4.10.
To view the relay (hardware) settling time of the system,
press the MENU key until the display reads:
HWSETL 015 mS
In this example, there is a Model 7072 or 7073 matrix card
present in the system. Press CANCEL to exit the menu
mode.
See paragraph 4.11 for a discussion of settling times and
triggers.
4.9.7 Card labels
Each matrix card can be identified by the Model 707A. You
can view the card labels of the present configuration by using
a menu item. Press the MENU key until the alphanumeric
display reads:
1 7072
In this case, a Model 7072 is in slot #1. Use the SCROLL to
view the card label of the next slot. If no card is present, the
display will be:
2 NONE
Continue pressing the SCROLL
or
keys for the
remaining slots or press CANCEL to exit the menu mode.
In master/slave configurations, all units display card labels
simultaneously.
4-18
If there is an error in ROM or RAM, a ROM FAIL or RAM
FAIL message is displayed until a key press or bus operation.
See Section 7 for troubleshooting procedures.
For master/slave configurations, all units are tested simultaneously, so you might have to run the test more than once to
inspect all LED indicators.
4.9.9 Factory defaults
A menu item can be used to return the Model 707A to the
factory default conditions previously listed in Table 4-2. To
initiate this action, follow these steps:
1. Press the MENU key until the display shows FACTORY
INIT.
2. Press the ENTER key. The display will read ENTER IF
SURE. (This additional keypress is to prevent unintentional initialization.) At this step you can press CANCEL to exit menu mode, or you can continue with the
next step.
3. Press the ENTER key again. The Model 707A will return to factory settings and exit menu mode.
In master/slave configurations, all units return to factory
defaults when this menu item is selected from the master
unit.
Operation
4.10 Selecting switching parameters
4.10.2 Make/break and break/make rows
The Model 707A has three switching parameters that are
user-modified: the programmed settling time, make-beforebreak rows, and break-before-make rows. These values of
these parameters are in effect for all relay switching until
they are changed. Figure 4-14 shows the front panel keys of
the switching group.
Make-before-break switching of relays is defined as connecting a new circuit before disconnecting the present circuit. It is used to eliminate transients caused by switching
between current sources. Break-before-make switching
means to disconnect the present circuit before connecting a
new circuit. It is used to avoid momentary shorting of two
voltage sources. Both of these switching operators are supported by the Model 707A.
SWITCHING
Rows of crosspoint relays are user-selectable for make/break
(make-before-break), break/make (break-before-make), or
“don't care” operation. The selections will be in effect for all
switching until new choices are made. When make/break or
break/make operation is chosen, the Model 707A automatically switches the crosspoint relays through intermediate setups to perform the following steps:
SETTLING TIME
MAKE/BREAK
BREAK/MAKE
1.
2.
3.
4.
Figure 4-14
Switching keys
4.10.1 Programmed settling time
The programmed settling time is a variable switching delay
that can be used to lengthen the fixed delay of the relay
(hardware) settling time. You can select, in 1msec increments, up to 65 seconds of an additional switching delay.
If an additional trigger is received during this time, it is processed and the message NOT SETTLED is displayed. At the
end of the programmed settling time. the Model 707A sets
the MATRIX READY output true.
To view or change the programed settling time, press the
SETTLING TIME key in the SWITCHING key group. The
value of the programmed settling time value is displayed as:
SETL 00000 mS
To exit the display without changing the value, just press
CANCEL. To change the value, enter between 0-65000 with
the data entry keys and press ENTER. This action also
returns the display to the RELAY STEP and MEMORY
STEP.
Crosspoints in break/make rows are opened.
Crosspoints in make/break rows are closed.
Crosspoints in make/break rows are opened.
Crosspoints in break/make rows are closed; crosspoints
in “don't care” rows are opened or closed accordingly.
These steps are transparent to the user except for the increased settling time. If either make/break or break/make
rows are not selected, the appropriate steps in the previous
list are deleted and the total settling time decreases. As make/
break and break/make operations affect settling times and
trigger response, these operations are further discussed in
paragraph 4.11.
The front panel MAKE/BREAK and BREAK/MAKE keys
are used in conjunction with the data entry keys to select
rows for operation as make/break or break/make. When a
row designation (A-H) is selected and displayed by itself, the
MAKE/BREAK and BREAK/MAKE keys toggle the state
of the MAKE/BREAK or BREAK/MAKE LED for that row
and immediately reprograms the Model 707A for the new
operation. The INVALID INPUT message is displayed
briefly if you press the MAKE/BREAK or BREAK/MAKE
key without first selecting a row or if a row/column address
is displayed instead of just a row.
Note that selecting a row for make/break de-selects it for
break/make and vice versa. The various front panel operations are listed in Table 4-7.
The programmed settling time is in effect for all crosspoint
relay open/close operations until it is reprogrammed. Its
effect on trigger response times is described in paragraph
4.11.
4-19
Operation
Table 4-7
Make/break and break/make front panel operation
Present State
Action
Next State
Don't Care
Select Make/Break
Select Break/Make
Make/Break
Break/Make
Make/Break
Select Break/Make
De-select Make/Break
Break/Make
Don't Care
Break/Make
Select Make/Break
De-select Break/Make
Make/Break
Don't Care
The optional light pen can be used to toggle the LED states
directly. The light pen can also select rows for make/break or
break/make operation from slave units. The row selection is
in effect for all units connected in a master/slave
configuration.
4.11.1 Trigger sources
The programmed trigger source provides the stimulus to
increment to the next stored setup. Trigger sources include:
• Front panel MANUAL key — When triggers are
enabled, this key is always operational (on stand-alone
and master units) regardless of the selected source
(unless the unit is placed in remote over the IEEE-488
bus).
• External trigger pulse — An appropriate pulse, applied
to the EXTERNAL TRIGGER INPUT jack on the rear
panel, provides the trigger stimulus.
• IEEE command triggers — IEEE-488 GET, X, or talk
commands provide the stimulus when the appropriate
source is selected.
Select the trigger source as follows:
1. Press SOURCE and note that the current trigger source
is displayed:
TRIG ON EXT
4.11 Triggering
When a Model 707A stand-alone or master unit is triggered,
the stored relay setup from RELAY STEP+1 is sent to the
relays. Triggers are enabled with the front panel ENABLE
key of the TRIGGER group (see Figure 4-15). This key toggles between triggers enabled and triggers disabled. When
triggers are enabled, the ENABLE LED is lit.
TRIGGER
This is the display for external triggering (the power-up
default). Table 4-8 lists the displays for all trigger
sources.
2. Press the SCROLL or keys until the desired trigger
source is displayed. Then press ENTER to select it and
exit menu mode.
3. If another source is scrolled to before pressing ENTER,
pressing CANCEL once returns the old selection, pressing it again exits menu mode.
ENABLE
SOURCE
MANUAL
Figure 4-15
Trigger keys
The maximum trigger rate is specified with no make/break or
break/make rows selected. As will be described in paragraph
4.11.3, additional switching delays are necessary with make/
break or break/make operation.
4-20
Table 4-8
Front panel messages for trigger sources
Message
Description 1
TRIG ON TALK
TRIG ON GET
TRIG ON X
TRIG ON EXT
TRIG ON KEY
IEEE talk command
IEEE GET command
IEEE X command
External trigger pulse
Front panel MANUAL key
only*
*If triggers are enabled, pressing MANUAL emulates the selected trigger
source.
Operation
4.11.2 Front panel triggering
To trigger the Model 707A from the front panel, simply press
the MANUAL key. (Press and hold for auto-repeat.) If triggers are enabled, this key is always operational regardless of
the selected trigger source (unless the unit is placed in
remote over the IEEE-488 bus, in which case all front panel
keys except LOCAL are locked out). Thus, front panel trigger source selection (TRIG ON KEY) provides a means to
lock out all other trigger sources when only front panel triggering is desired.
Triggering will stop when the RELAY STEP field increments to 100. If you press MANUAL and the unit is not
ready, an error message will be displayed, as discussed in the
following paragraph.
4.11.3 Trigger overrun conditions
Once the instrument is triggered, it begins transferring relay
setup data from mainframe memory to the matrix cards. If a
second trigger is received while the unit is still transferring
data, a trigger overrun condition will occur. In this case, the
second trigger is not processed and the unit will display the
following error message:
TRIG OVERRUN
After the time required for transferring relay data has
elapsed, the Model 707A is able to process another trigger. If
a trigger is received before the programmed settling time has
elapsed, the following message is displayed:
NOT SETTLED
Figure 4-16 shows an example setup change and a timing
diagram of the READY (for trigger) pulse and a high true
MATRIX READY pulse when the Model 707A is processing
the trigger. (The status of these signals is available in the
serial poll byte, see Section 5.) This timing is for setups with
no make/break or break/make rows.
1. Closes crosspoints in make/break rows yielding an
intermediate setup.
2. Opens crosspoints in make/break rows and opens/closes
crosspoints in “don't care” rows yielding the desired
setup.
If only break/make rows are selected, the Model 707A takes
these steps:
1. Opens crosspoints in break/make rows yielding an intermediate setup.
2. Closes crosspoints in break/make rows and opens/closes
crosspoints in “don't care” rows yielding the desired
setup.
An example of these operations is shown in Figure 4-17 with
its corresponding timing diagram. By comparing Figures
4-16 and 4-17, you can see that the intermediate setup
needed for make/break or break/make causes a delay in the
assertion of READY and MATRIX READY equal to the
relay settling time.
When a combination of make/break and break/make rows
are selected, the Model 707A must switch through three
intermediate setups to ensure proper relay operation. The
steps taken by the unit are as follows:
1. Opens crosspoints in break/make rows yielding the first
intermediate setup.
2. Closes crosspoints in make/break rows yielding the second intermediate setup.
3. Opens crosspoints in make/break rows yielding the third
intermediate setup.
4. Closes crosspoints in break/make rows and opens/closes
crosspoints in “don't care” rows yielding the desired
setup.
Figure 4-18 shows an example setup change with the necessary intermediate setups. As the timing diagram shows, three
additional relay settling time intervals are needed for the
intermediate setups.
When either make/break or break/make operation is
selected, but not both, the Model 707A switches through an
intermediate setup to ensure proper relay operation. If only
make/break rows are selected, the Model 707A takes these
steps:
4-21
Operation
State :
Don't Care
Setup N
A
1
2
X
X
Setup N + 1
3
1
A
X
3
X
Open Don't Care
Close Don't Care
Actions :
Setup Data
Shift
Relay
Settling Time
Ready
Matrix
Ready
TRIG
OVERRUN
Additional Trigger
not Processed
Figure 4-16
Timing without make/break or break/make rows
4-22
2
Commands
AA
AA
AAAAAAAAAA
AA
AA
Programmed
Settling Time
NOT SETTLED Message
Additional Trigger Is Processed
NA2
CA3
Operation
State :
Intermediate
Setup
1
2
3
Setup N
1
2
3
Setup N + 1
1
Make/Break
A
A
A
Don' t Care
B
B
B
Actions :
Close Make/Break
2
3
Commands
NA2, B2
CA3, B3
Open Make/Break
Open Don't Care
Close Don't Care
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
Make/Break Operation
Break/Break Operation
Setup N
1
2
Intermediate
Setup
1
2
3
3
Setup N+1
1
Break/Make
A
A
A
Don't Care
B
B
B
Actions :
Open Break/Make
Setup Data
Shift
2
3
Commands
NA,2 B2
CA3, B3
Close Break/Make
Open Don't Care
Close Don't Care
Setup Data
Shift
Relay
Settling Time
Ready
Matrix
Ready
TRIG OVERRUN
Error
Additional Trigger
Not Processed
Relay
Settling Time
Programmed
Settling Time
AAAAAAAA
AA
NOT SETTLED
Message
Additional Trigger
is Processed
Figure 4-17
Timing with either make/break or break/make rows
4-23
Operation
State:
Setup N
Intermediate
Setup A
Intermediate
Setup B
Intermediate
Setup C
Setup N+1
1 2 3
1 2 3
1 2 3
1 2 3
1 2 3
Make/Break
A
A
Break/Make
Don't Care
B
C
B
C
A
B
A
B
C
C
Open Break/Make Close Make/Break
Actions:
Setup Data
Shift
Relay
Settling Time
Setup Data
Shift
Relay
Settling Time
Open Make/Break
Setup Data
Shift
Relay
Settling Time
Commands
NA2, B2, C2
CA3 , B3, C3
A
B
C
Close Break/Make
Open Don't Care
Close Don't Care
Setup Data
Shift
Relay
Settling Time
Programmed
Settling Time
Ready
AAAAAAAA
Matrix
Ready
TRIG OVERRUN Error
Additional Trigger not Processed
Figure 4-18
Timing with both make/break and break/make rows
4-24
NOT SETTLED Message
Additional Trigger is Processed
Operation
4.11.4 External trigger input
4.11.6 IEEE-488 bus triggering
To use external triggering, first select that source with the
MENU and SCROLL keys as described in paragraph 4.11.1.
With triggers enabled, the unit will then be triggered when an
input pulse with the specifications previously shown in Figure 4-10 is applied to the EXTERNAL TRIGGER INPUT
jack. The unit is triggered on either the falling (1eading) or
rising (trailing) edge of the pulse, as selected by a menu item.
To trigger a setup change with an IEEE-488 trigger source,
you must send the appropriate IEEE-488 command over the
bus: X, talk, or GET depending on the selected source. Trigger on GET allows the fastest IEEE-488 triggering response.
See Section 5 for details on bus triggering.
4.11.5 Matrix ready output
The matrix ready output provides a TTL-compatible signal,
as shown previously in Figure 4-11. This signal can be used
to inform other instruments when the total settling time is
complete. It is programmable by a menu item for high or low
true. The leading edge of the “true” level indicates the end of
the total settling time (relay settling time plus programmed
settling time).
If one of these commands has been selected as the trigger
source, you can also trigger the unit by pressing the MANUAL key unless the unit is in remote.
4.12 Resetting
The reset operation performs the same functions as cycling
power except power-up self-checking. If a master/slave error
is detected during reset, the unit will revert to stand-alone
operation. The front panel RESET key is used to initiate a
reset operation.
Reset, power-up, and factory default conditions were previously listed in Table 4-2.
4-25
5
IEEE-488 Programming
5.1
Introduction
Step 2: Select the primary address
This section contains information on programming the
Model 707A over the IEEE-488 bus. Detailed instructions
for all programmable functions are included. However,
information concerning operating modes presented elsewhere are not repeated.
The primary address is a way for the controller to refer to
each device on the bus individually. Consequently, the primary address of your Model 707A must be the same as the
primary address specified in the controller's programming
language, or you cannot program the instrument. Each
device on the bus must have a different primary address.
5.2
The primary address of your Model 707A is set to 18 at the
factory, but you can set the address to values between 0 and
30 for a stand-alone unit, or 31 and 60 for a master in a master/slave loop (refer to paragraph 5.5).
IEEE-488 quick start
The following paragraphs provide a step-by-step procedure
for putting a Model 707A on the bus to program some basic
commands.
Step 1: Connect the Model 707A to the controller
With power off, connect the Model 707A to the IEEE-488
interface of the controller using a standard interface cable.
Some controllers include an integral cable; others require a
separate cable. Paragraph 5.3 discusses bus connections in
detail.
Step 3: Write your program
All operations require a simple program to send commands
to the instrument. Figure 5-1 shows a flowchart of a program
to select make/break and break/make rows, modify crosspoints of a setup stored in memory, send the setup to the
relays, and then request data of the present relay setup.
The corresponding program (written in MS QBASIC supplied with MS-DOS 5.0 and later) is contained in three parts
for this example. The program assumes a primary IEEE-488
address of 18 for the Model 707A and that power-up default
conditions exist in the unit.
5-1
IEEE-488 Programming
Sample Program
Comments
DIM A$[200],C$[200]
PRINT #1, "REMOTE 18"
' Dimension crosspoint input and display.
' Tell Model 707A (at IEEE-488 location 18) to
' listen over bus.
' Select rows A and B for make/break and rows
' G and H for break/make.
' Set edit pointer to setup #1, and send setup #1
' to relays and display.
' Allow user to input crosspoint data.
' Check for null string.
' Send command string to Model 707A.
' Allow user to input additional crosspoint data.
PRINT #1, "OUTPUT 18;V11000000W00000011X"
PRINT #1, "OUTPUT 18;E1Z1,0X"
COMMAND:
LINE INPUT "CROSSPOINTS COMMAND", C$
IF LEN (C$)=0 THEN STOP
PRINT #1, "OUTPUT 18;C$+"X"
GOTO COMMAND
END
Step 4: Open and close crosspoints
Start
Place Unit in Remote
Select Make/Break
and Break/Make Rows
Set Edit Pointer to Setup
Memory
Open and Close
Crosspoints of Setup
You can open, close, and clear crosspoints by sending the
appropriate command, which is made up of an ASCII letter
representing the command, followed by one or more characters for the command options. Commands can be grouped
together in one string. The command strings are not opening
and closing relays unless the edit pointer is set to zero.
To open and close crosspoints over the bus, run the previous
program and enter a command string when prompted. Some
example strings are shown in Table 5-1.
Terminate each string by pressing RETURN on the controller keyboard. If a null string is entered, the program ends.
Table 5-1
Sample strings
Sample string
Description
"P1"
Clear (open) all crosspoints of
setup #1.
Set (close) crosspoints A5, A6,
B9, B10.
Clear (open) crosspoints A5, A6.
Set (close) A1, A2 and clear
(open) B9, B10.
Get Setup and Display
"CA5,A6,B9,B10"
Trigger Setup to
Relays
"NA5,A6"
"CA1,A2NB9,B10"
End
Figure 5-1
Flowchart of example program
5-2
IEEE-488 Programming
Step 5: Modify program for requesting data
To display or print setup data, you must specify one of the
data output formats that sends ASCII characters. Note that a
variety of data formats are available, as discussed in paragraph 5.9. The data can be a setup stored in memory or the
present relay setup. Modify the previous sample program
with the following statements. Add the statements immediately before the GOTO line.
PRINT #1, "OUTPUT 18;
U2,1G2X"
PRINT #1, "ENTER 18"
LINE INPUT #2, A$
PRINT A$
' Set data format for setup #1.
' Get stored setup data
' and print.
5-2. Two screws are located on each connector to ensure that
connections remain secure. Present standards call for metric
threads, as identified by dark colored screws. (Earlier versions had silver colored screws. Do not use these connectors
with the Model 707A.)
AA
AA
When the program is run with these statements, it lists the
closed crosspoints that you have entered.
Step 6: Modify program for triggering
Triggers provide a quick way for copying relay data from a
pre-programmed setup to the relays. Each valid trigger
causes the next sequential setup to be copied to the relays and
the relay pointer to be updated.
Modify the previous sample program with the following
statements. Add the statements immediately before the END
line.
PRINT "PRESS ANY KEY TO
CONTINUE"
DO
LOOP WHILE INKEY$=" "
PRINT #1, "OUTPUT
18;F1T2X"
PRINT #1,"TRIGGER 18"
' Wait for keypress.
Figure 5-2
IEEE-488 connector
A typical connecting scheme is shown in Figure 5-3. Each
cable normally has a standard connector on each end. These
connectors are designed to be stacked to allow a number of
parallel connections on one instrument. To avoid possible
damage, do not stack more than three connectors on any one
instrument.
Instrument
Instrument
Model 707
' Enable triggers, select
' trigger-on GET.
' Trigger setup #1 to
' relays.
When any key on the keyboard is pressed, this program modification triggers setup #1 to the relays. This is because the
relay step pointer, which is different from the edit pointer,
was set to zero by power-up.
5.3
Bus cable connections
The following paragraphs provide information needed to
connect instrumentation to the IEEE-488 bus. The Model
707A is connected to the IEEE-488 bus through a cable
equipped with standard IEEE-488 connectors. See Figure
Figure 5-3
IEEE-488 connections
Controller
5-3
IEEE-488 Programming
NOTE
To minimize interference caused by electromagnetic radiation, use only shielded
IEEE-488 cables. The Model 7007-1 and
7007-2 shielded IEEE-488 cables are
available from Keithley Instruments.
Connect the cable to the Model 707A as follows:
1. Line up the connector on the cable with the connector on
the rear panel of the instrument. Figure 5-4 shows the
IEEE-488 connector location.
2. Tighten screws securely, but do not overtighten them.
(Overtightening can break the connector.)
3. Add additional connectors from other instruments, as
required.
4. Make sure the other end of the cable is properly connected to the controller. Some controllers have an IEEE-488
type connector, while others do not. Consult the instruction manual of your controller for the proper connecting
method.
NOTE
The IEEE-488 bus is limited to a maximum of 15 devices, including the controller. Also, the maximum cable length is
limited to 20 meters, or 2 meters multiplied by the number of devices, whichever
is less. Failure to observe these limits may
result in erratic bus operation.
In master/slave configurations, only the
master unit is connected to the IEEE-488
bus. If slave units are also connected, erratic bus operation results. Custom cables
may be constructed by using the contact
assignments listed in Table 5-2 and shown
in Figure 5-5.
Figure 5-4
IEEE-488 connector location
5-4
IEEE-488 Programming
5.4
Table 5-2
Contact assignments
Contact
Number designation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
DIO1
DIO2
DIO3
DIO4
EOI (24)*
DAV
NRFD
NDAC
IFC
SRQ
ATN
SHIELD
DIO5
DIO6
DIO7
DIO8
REN (24)*
Gnd, (6)*
Gnd, (7)*
Gnd, (8)*
Gnd, (9)*
Gnd, (10)*
Gnd, (11)*
Gnd, LOGIC
IEEE-488 type
Data
Data
Data
Data
Management
Handshake
Handshake
Handshake
Management
Management
Management
Ground
Data
Data
Data
Data
Management
Ground
Ground
Ground
Ground
Ground
Ground
Ground
*Number in parentheses refers to the signal ground
return of reference contact number. EOI and REN signal lines return on contact 24.
CONTACT 12
CONTACT 1
Interface function codes
The interface function codes, which are part of the IEEE488 standards, define an instrument's ability to support
various interface functions. They should not be confused
with programming commands found elsewhere in this
manual. Interface function codes for the Model 707A are
listed in Table 5-3. The codes define Model 707A
capabilities as follows:
SH1 (Source Handshake) — SH1 defines the ability of the
Model 707A to properly handshake data or command bytes
when the unit is a source.
AH1 (Acceptor Handshake) — AH1 defines the ability of
the Model 707A to properly handshake the bus when it is an
acceptor of data or commands.
T6 (Talker) — The ability of the Model 707A to send data
over the bus to other devices is defined by the T6 function.
Model 707A talker capabilities exist only after the instrument has been addressed to talk. T6 means that the Model
707A is a basic talker, has serial poll capabilities, and is
unaddressed to talk when it receives its own listen address.
TE0 (Extended Talker) — The Model 707A does not have
extended talker capabilities.
L4 (Listener) — The L4 function defines the ability of the
Model 707A to receive device-dependent data over the bus.
Listener capabilities exist only after the instrument has been
addressed to listen. L4 means that the Model 707A is a basic
listener and is unaddressed to listen when it receives its own
talk address.
LE0 (Extended Listener) — The Model 707A does not have
extended listener capabilities.
SR1 (Service Request) — The SR1 function defines the
ability of the Model 707A to request service from the
controller.
RL1 (Remote Local) — The RL1 function defines the capabilities of the Model 707A to be placed in the remote or local
states.
CONTACT 24
Figure 5-5
Contact assignments
CONTACT 13
PP0 (Parallel Poll) — PP0 means that the Model 707A does
not have parallel polling capabilities.
DC1 (Device Clear) — The DC1 function defines the ability
of the Model 707A to be cleared (initialized).
DT1 (Device Trigger) — The ability for the Model 707A to
have setups triggered is defined by the DT1 function.
C0 (Controller) — The Model 707A has no controller
capabilities.
E1 (Bus Driver Type) — The Model 707A has open-collector bus drivers.
5-5
IEEE-488 Programming
Table 5-3
Model 707A interface function codes
Code
Interface function
SH1
AH1
T6
Source Handshake capability.
Acceptor Handshake capability.
Talker (basic talker, serial poll, unaddressed to
talk on MLA1).
No Extended Talker capabilities.
Listener (basic listener, unaddressed to listen on
MTA2).
No Extended Listener capabilities.
Service Request capability.
Remote Local capability.
No Parallel Poll capability.
Device Clear capability.
Device Trigger capability.
No Controller capability.
Open-collector bus drivers.
TE0
L4
LE0
SR1
RL1
PP0
DC1
DT1
C0
E1
1
2
MLA – My Listen Address.
MTA – My Talk Address
5.5
Primary address programming
The Model 707A must receive a listen command before it
responds to addressed commands. Similarly, the unit must
receive a talk command before it transmits data. The Model
707A is shipped from the factory with a programmed primary address of 18. The programming examples included in
this manual assume that address.
5-6
The primary address may be set to any value between 0 and
30 as long as address conflicts with other instruments are
avoided. Note that controllers are also given a primary
address, so do not use that address either. Most frequently,
controller addresses are 0 or 21, but you should consult the
controller’s instruction manual for details. Whatever primary
address you choose, you must be certain that it corresponds
with the value specified as part of the controller’s programming language.
To check the present primary address, or to change to a new
one, perform the following procedure:
1. Press the MENU button until the current primary address is displayed. For example, if the instrument is set
to primary address 18, the following message is displayed:
IEEE-488 18
2. To retain the current address, press CANCEL to exit
from the menu.
3. To change the primary address, use the numeric buttons
and press ENTER. This stores the new address in memory so that the instrument powers up to that address.
NOTE
Each device on the bus must have a unique
primary address. Failure to observe this
precaution will probably result in erratic
bus operation.
IEEE-488 Programming
5.6
QuickBASIC programming
Programming examples are written in Microsoft
QuickBASIC 4.5 using the Keithley KPC-488.2 (or Capital
Equipment Corporation) IEEE interface and the HP-style
Universal Language Driver (CECHP).
Before any programming example can be run, the Universal
Language Driver must be installed. To install the driver, enter
CECHP at the DOS prompt.
Program fragments are used to demonstrate proper programming syntax. As the name implies, only a fragment of the
whole program is used to avoid redundancy. At the beginning
of each program, driver files must be opened. The input terminator should be set for CRLF. For example:
OPEN “ieee” FOR OUTPUT AS #1
OPEN “ieee” FOR INPUT AS #2
PRINT #1, “interm crlf”
A partial list of BASIC statements is shown in Table 5-4.
If you include the CECHP command in your
AUTOEXEC.BAT file, the driver will automatically be
installed each time you turn on your computer.
Table 5-4
BASIC IEEE-488 statements
Action
Basic statement
Transmit string to device 18.
Obtain string from device 18.
Read string.
Display string.
Send GTL to device 18.
Send SDC to device 18.
Send DCL to all devices.
Send remote enable.
Cancel remote enable.
Serial poll device 18.
Send local lockout.
Send GET to device 18.
Send IFC.
PRINT #1, "OUTPUT 18",A$
PRINT #1, "ENTER 18"
LINE INPUT #2, A$
PRINT A$
PRINT #1, "LOCAL 18"
PRINT #1, "CLEAR 18"
PRINT #1, "CLEAR"
PRINT #1, "REMOTE"
PRINT #1, "LOCAL"
PRINT #1, "SPOLL(18)"
PRINT #1, "LOCAL LOCKOUT"
PRINT #1, "TRIGGER 18"
PRINT #1, "ABORT"
5-7
IEEE-488 Programming
5.7
Front panel aspects of IEEE-488
operation
The following paragraphs discuss aspects of the front panel
that are part of IEEE-488 operation, including front panel
error messages, IEEE-488 status indicators, and the LOCAL
key.
Card identification error
A card ID error occurs when the instrument's power-up routine detects a checksum error in the information from a card.
When in master/slave configuration, the cards in error are
indicated by all LEDs in their crosspoint display blocks
being lit.
IDDC (illegal device-dependent command) error
5.7.1 Front panel error messages
The Model 707A has a number of front panel messages associated with IEEE-488 programming. These messages, which
are listed in Table 5-5, inform you of certain conditions that
occur when sending device-dependent commands to the
instrument.
The following paragraphs describe the front panel error messages associated with IEEE-488 programming. Note that the
instrument may be programmed to generate an SRQ, and U
command status words can be checked for specific error conditions if any of these errors occur. See paragraphs 5.9.14
and 5.9.22.
Table 5-5
Front panel IEEE-488 error messages
Type of error
Description
CARD ID ERROR
Power-up routine cannot identify one or more cards.
Illegal device-dependent command received.
Illegal device-dependent command option received.
Master/slave communication or
timing error.
X received while unit is in
LOCAL state.
Unit triggered before total settling time expired.
Power-up routine or self-test
detected RAM error.
Power-up routine or self-test
detected program ROM checksum error.
Power-up routine detected
checksum errors in one or more
setups. (Affected setups are
cleared.)
Unit triggered before Ready bit
is set.
IDDC
IDDCO
M/S ERROR
NOT IN REMOTE
NOT SETTLED
RAM FAIL
ROM FAIL
SETUP ERROR
TRIG OVERRUN
5-8
An IDDC error occurs when the unit receives an illegal
device-dependent command over the bus. For example, the
command string 1X includes an illegal command because
the “1” is not part of the instrument's programming language.
NOTE
When an IDDC error is detected in a command string, all commands in the string,
up to and including the next X, are ignored.
To correct the error condition, send only valid commands.
Refer to paragraph 5.9 for device-dependent command programming details. An IDDC error is flagged in the U1 word,
as discussed in paragraph 5.9.22.
IDDCO (illegal device-dependent command option)
error
Sending the instrument a legal command with an illegal
option results in an IDDCO error.
For example, the command K9X has an illegal option (9) that
is not part of the instrument's programming language. Thus,
although the command K is valid, the option is not, and the
IDDCO error results.
NOTE
When an IDDCO error is detected in a
command string, all commands in the
string, up to and including the next X, are
ignored.
To correct this error condition, use only valid command
options, as discussed in paragraph 5.9. An error is flagged in
the U1 word, as discussed in paragraph 5.9.22.
Master/slave error
A master/slave error occurs when a communication or
timing error is detected in the closed loop of units. If one or
more errors are detected, the message M/S ERROR is
displayed.
IEEE-488 Programming
To simulate the error condition, disconnect a DIN cable from
either of the MASTER/SLAVE connectors. The condition is
detected when the Model 707A performs the next operation
that requires communication among the units. A master/
slave error is flagged in the U1 word, as discussed in paragraph 5.9.22.
Overrun triggers do not affect the instrument except to generate the error. In other words, the present setup change is not
aborted by the overrun trigger stimulus, and the trigger is
ignored. Note that a trigger overrun error is also flagged in
the U1 word, as discussed in paragraph 5.9.22.
Not in remote error
5.7.2 Status indicators
A not in remote error occurs if the instrument receives an
“X” while it is in the local state. This is caused by failing to
set the REN line true before addressing the Model 707A to
listen. A not in remote error is flagged in the U1 word, as discussed in paragraph 5.9.22.
The TALK, LISTEN, and REMOTE indicators show the
present IEEE-488 status of the instrument. Each of these
indicators is described below.
TALK
Not settled error
LISTEN
A trigger before settling time error occurs when the instrument receives an additional trigger before the settling time
has expired. This time period is after assertion of the
READY signal and before assertion of the MATRIX
READY signal. See paragraph 5.8 for a complete discussion
of trigger timing. Both READY and MATRIX READY are
bits in the SPOLL byte; MATRIX READY is also a rear
panel signal. Note that a master/slave error is also flagged in
the U1 word, as discussed in paragraph 5.9.22.
A trigger during this time period is processed normally.
RAM or ROM failure
A RAM or ROM failure occurs when the power-up routine
detects an error, either a RAM error or a checksum error in
program ROM. If an error is detected, a RAM FAIL or ROM
FAIL message is displayed (cleared by any keypress).
Setup error
A setup error occurs when the Model 707A power-up routine
detects a checksum error in one or more setups stored in nonvolatile memory. If an error is detected, SETUP ERROR is
displayed and the affected setups are cleared to all open. A
keypress will clear this error. Note that a setup error is also
flagged in the U1 word, as discussed in paragraph 5.9.22.
Trigger overrun (hardware) error
A trigger overrun occurs when the instrument is triggered
while it is still processing a setup change from a previous
trigger and before the READY (for trigger) signal is asserted.
READY is a bit in the SPOLL byte. See paragraph 5.8 for a
complete discussion of trigger timing. The exact trigger
stimulus depends on the selected trigger source, as discussed
in paragraph 5.9.21.
REMOTE
Figure 5-6
IEEE-488 indicators
TALK — This indicator is on when the instrument is in the
talker active state. The unit is placed in this state by addressing it to talk with the correct MTA (My Talk Address) command. TALK is off when the unit is in the talker idle state.
The instrument is placed in the talker idle state by sending it
an UNT (Untalk) command, addressing it to listen, or with
the IFC (Interface Clear) command.
LISTEN — This indicator is on when the Model 707A is in
the listener active state, which is activated by addressing the
instrument to listen with the correct MLA (My Listen
Address) command. Listen is off when the unit is in the listener idle state. The unit can be placed in the listener idle
state by sending UNL (Unlisten), addressing it to talk, or by
sending IFC (Interface Clear) over the bus.
REMOTE — This indicator shows when the instrument is in
the remote state. Note that REMOTE does not necessarily
indicate the state of the REN line, as the instrument must be
addressed to listen with REN true before the REMOTE indicator turns on. When the instrument is in remote, all front
panel keys except for the LOCAL key are locked out. When
REMOTE is turned off, the instrument is in the local state,
and front panel operation is restored.
5-9
IEEE-488 Programming
5.7.3 LOCAL key
The LOCAL key cancels the remote state and restores local
operation of the instrument.
LOCAL
Figure 5-7
LOCAL key
1. All front panel keys except for LOCAL are inoperative
while the Model 707A is in remote (REMOTE on). The
unit is placed in remote by addressing it to listen with
the REN line true. Thus, to control the unit from the
front panel, it is necessary to press LOCAL after programming over the bus. Note that LOCAL is also inoperative if the LLO (Local Lockout) command is in
effect.
2. Front panel parameter modification should always be
completed before attempting to use bus control. For
example, you should not attempt to program a setup
over the bus while editing a setup from the front panel.
5.8
Since all front panel keys except LOCAL are locked out
when the instrument is in remote, this key provides a
convenient method of restoring front panel operation.
Pressing LOCAL also turns off the REMOTE indicator, and
returns the display to normal if a message was displayed with
the D command. (See paragraph 5.9.5)
Note that the LOCAL key is inoperative if the LLO (Local
Lockout) command is in effect.
General bus command programming
5.8.1 Overview
General bus commands are those commands (such as DCL)
that have the same general meaning regardless of the instrument. Commands supported by the Model 707A are listed in
Table 5-8, which also lists BASIC statements necessary to
send each command. Note that commands requiring that a
primary address be specified assume that the Model 707A
primary address is set to 18 (its factory default address).
5.7.4 Concurrent front panel and bus operation
Fundamentally, there is no reason why you cannot control
the instrument simultaneously from the front panel and over
the IEEE-488 bus. However, the following points should be
kept in mind.
5-10
5.8.2 REN (remote enable)
The remote enable command is sent to the Model 707A by
the controller to set up the instrument for remote operation.
Generally, the instrument should be placed in the remote
state before you attempt to program it over the bus. Setting
REN true does not actually place the instrument in the
remote state. Instead the instrument must be addressed to listen after setting REN true before it goes into remote.
IEEE-488 Programming
Table 5-6
General bus commands/BASIC statements
Command
Basic statement
Effect on Model 707A
REN
IFC
LLO
GTL
DCL
SDC
GET
PRINT
PRINT
PRINT
PRINT
PRINT
PRINT
PRINT
Goes into effect when next addressed to listen.
Goes into talker and listener idle states.
LOCAL key locked out.
Cancel remote, restore front panel operation.
Return to default conditions.
Return to default conditions.
Triggers setup with GET source.
#1,
#1,
#1,
#1,
#1,
#1,
#1,
"REMOTE"
"ABORT"
"LOCAL LOCKOUT"
"LOCAL 18"
"CLEAR"
"CLEAR 18"
"TRIGGER 18"
NOTE
The instrument need not be in remote to be
a talker. All front panel controls (except
LOCAL and POWER) are inoperative
while the instrument is in remote. You can
restore normal front panel operation by
pressing the LOCAL key.
5.8.3 IFC (interface clear)
The IFC command is sent by the controller to place the
Model 707A in the local, talker, and listener idle states. The
unit responds to the IFC command by canceling front panel
TALK or LISTEN lights, if the instrument was previously
placed in one of those states.
5.8.4 LLO (local lockout)
The LLO command is used to prevent local operation of the
instrument. After the unit receives LLO, all of its front panel
controls except POWER are inoperative.
5.8.5 GTL (go to local)
The GTL command is used to take the instrument out of the
remote state. Operation of the front panel keys will also be
restored by GTL unless LLO is in effect. To cancel LLO, you
must set REN false.
5.8.6 DCL (device clear)
The DCL command may be used to clear the Model 707A
and return it to its power-up default conditions (see Table
5-2). Note that the DCL command is not an addressed com-
mand, so all instruments equipped to implement DCL will do
so simultaneously. When the Model 707A receives a DCL
command, it returns to the power-up default conditions. DCL
does not affect the programmed primary address.
5.8.7 SDC (selective device clear)
The SDC command is an addressed command that performs
essentially the same function as the DCL command. However since each device must be individually addressed, the
SDC command provides a method to clear only selected
instruments instead of clearing all instruments simultaneously, as is the case with DCL. Any devices on the bus that
are addressed to listen are cleared. When the Model 707A
receives the SDC command, it returns to the power-up
default conditions.
5.8.8 GET (group execute trigger)
GET may be used to initiate a Model 707A setup change if
the instrument is placed in the appropriate trigger source.
Refer to paragraph 5.9 for more information on triggering.
5.8.9 SPE, SPD (serial polling)
The serial polling sequence is used to obtain the Model 707A
serial poll byte. The serial poll byte contains important information about internal functions, as described in paragraph
5.9.14. Generally, the serial polling sequence is used by the
controller to determine which of several instruments has
requested service with the SRQ line. However, the serial
polling sequence may be performed at any time to obtain the
serial poll byte from the Model 707A.
5-11
IEEE-488 Programming
Table 5-7
Factory default, power-up, and DCL/SDC conditions
Parameter
Factory default
Power-up, DCL/SDC Description
Relays
Stored Setups
Relay Step
Memory Step
Master/Slave
IEEE-488 Address
External Trigger
Matrix Ready
Display
Edit Pointer
Trigger Enable
Data Format
EOI/Hold-off
SRQ
Digital Output
Programmed Settling Time
Trigger Source
Make/Break Rows
Break/Make Rows
Terminator
All opened
All cleared
000
001
Stand-alone
18 (Note 1)
A0
B0
DX
E0
F0
G0
K0
M0
O000
S0
T7
V00000000
W00000000
Y0
All opened
Not affected
000
001
(Notes 2, 3)
Not affected
A0
B0
DX
E0
F0
G0
K0
M0
O000
S0
T7
Not affected
Not affected
Y0
—
—
Point to relays
Point to setup 1
—
—
Falling edge triggers
Negative true
Normal alphanumeric display
Point to relays
Triggers disabled
Full output, all data sent in one talk
Both enabled
Disabled
Output lines low
0ms
External trigger
None selected
None selected
<CR><LF>
Notes:
1. The IEEE-488 address is not affected by the Restore (R0) command.
2. Units previously defined as stand-alone or slave will power up as stand-alone units. They become slave units when a master unit initializes a master/slave loop upon power up.
3. DCL/SDC does not affect master/slave state. DCL/SDC does clear slaves.
5.9
Device-dependent command (DDC)
programming
Some commands permit more than one option; these must be
separated with commas. For example, the close crosspoints
commands have the general format:
5.9.1 Overview
Crc(,rc)...(,rc)
IEEE-488 device-dependent commands control most instrument operating modes. All front panel modes (such as trigger
source and settling time), as well as some modes not available from the front panel (like SRQ and terminator) can be
programmed with these commands.
Here the “rc” options are row and column addresses, while the
commas indicate the necessary delimiters. The parentheses
indicate that the option and associated delimiter are optional.
Command syntax
Each command is made up of a single ASCII capital letter
followed by one or more numbers or letters representing an
option(s) of that command. For example, the trigger source
can be set over the bus by sending the letter “T” followed by
a number representing the trigger option. T1X would be sent
to trigger on talk. The IEEE-488 bus treats these commands
as data; they are sent with the ATN line false.
5-12
NOTE
Do not include parentheses in actual command strings.
Multiple commands
A number of commands can be grouped together in one command string, which is generally terminated by the “X” character. This character tells the instrument to execute the
command or command string as described in paragraph
5.9.25. Commands sent without the X character are not exe-
IEEE-488 Programming
cuted at that particular time, but they are stored within an
internal command buffer for later execution when the X
character is finally received.
If a particular command occurs “n” times in a command
string, then the “nth” occurrence is the only one used (i.e.,
T0T2T4X appears to the Model 707A as T4X).
Table 5-8
Order of command execution
Order Command Description
1
2
3
X
R
L
4
5
6
7
E
I
Q
P
8
Z
9
10
11
V
W
N
12
C
13
A
14
B
15
16
17
18
D
F
G
J
19
20
21
22
23
24
25
26
K
M
O
S
T
U
Y
H
Invalid commands
If an invalid command is sent as part of the command string,
no commands in the string are executed. Under these conditions, the instrument displays a front panel error message
(IDDC or IDDCO), as described in paragraph 5.7, and it can
be programmed to generate an SRQ (Service Request), as
discussed in paragraph 5.9.14. Checking is done as syntactical groups of characters are received.
Valid command strings (typical samples)
A0X
A0T6X
P 0X
Z15,0X
Single command string.
Multiple command string.
Space is ignored
Multiple-option command string (options separated by commas).
Invalid command strings (typical samples)
1X
K7X
CA4OOX
Z0100X
Invalid command as 1 is not a valid command.
Invalid command option as 7 is not a valid
option of the K command.
Invalid option (maximum column address is
60).
Multiple-option command without the necessary separating commas.
Order of command execution
Device-dependent commands are not necessarily executed in
the order received. Rather, each instrument always executes
them in a specific order. The order of execution for the Model
707A is summarized in Table 5-10. Note that the X command is listed first since it is the character that forces the execution of the rest of the commands.
If you wish to force a particular order of execution, include
the execute (X) character after each command option grouping in the command string. For example, the following string
would be executed in the received order: T6XA1XR0X.
Execute DDCs.
Restore factory default conditions.
Download setups from controller to
Model 707A.
Set the edit pointer.
Insert a blank setup in memory.
Delete a setup from memory.
Clear all crosspoints at specified
setup.
Copy a setup from memory or relays
to memory or relays.
Select rows from make/break.
Select rows for break/make.
Open crosspoints of setup indicated
by edit pointer.
Close crosspoints of setup indicated
by edit pointer.
Select trigger edge of External Trigger pulse.
Select logic sense of Matrix Ready
signal.
Display a user message.
Enable/disable triggers.
Select data output format.
Execute ROM/RAM/display selftest.
Select EOI and hold-off on X.
Set the SRQ mask.
Set the digital output.
Program the settling time.
Select the trigger source.
Request status.
Select terminator characters.
Hit a front panel key.
Device-dependent command summary
All Model 707A device-dependent commands are summarized in Table 5-11, which also lists respective paragraphs
where more detailed information on each command may be
found.
5-13
IEEE-488 Programming
Table 5-9
DDC summary
Mode
Command
Description
Para.
External Trigger
A0
A1
B0
B1
Crc(,rc)...(,rc)
Falling edge triggers Model 707A
Rising edge triggers Model 707A
Negative true Matrix Ready output
Positive true Matrix Ready output
Close crosspoints of setup indicated by edit pointer
(rows A-H, columns 1-360)
Display ASCII character (14 max)
Return alphanumeric display to normal
Point to present relay setup
Point to stored relay setup (1-100)
Disable triggers
Enable triggers
Full output, all data in one talk
Full output, one switching system row per talk
Inspect output, all data in one talk
Condensed output, all data in one talk
Condensed output, one switching system per talk
Binary output, all data in one talk
Binary output, one switching system per talk
Emulate front panel key press (1-41)
Insert blank setup in memory (1-100)
Perform self-test
Send EOI, hold-off on X until Ready
No EOI, hold-off on X until Ready
Send EOI, do not hold-off on X
No EOI, do not hold-off on X
Send EOI, hold-off on X until Matrix Ready
No EOI, hold-off on X until Matrix Ready
Download setups from controller to Model 707A
SRQ disabled
Not used
Not used
Matrix Ready
Ready for trigger
Error
Not used
Open crosspoints of setup indicated by edit pointer
(rows A-H, columns 1-360)
Set states of digital output lines (000-255)
Open all crosspoint relays
Clear all crosspoints of stored setup (1-100)
Delete setup from memory (1-100)
Restore factory defaults
Program settling time in milliseconds (0-65000)
Trigger on talk
Trigger on GET
Trigger on X
Trigger on External Trigger pulse
Trigger on front panel MANUAL key only
5.9.2
Matrix Ready
Close Crosspoint
Display
Edit Pointer
Enable/Disable Triggers
Data Format
Hit Key
Insert Blank Setup
Self-test
EOI and Hold-off
Download Setups
SRQ
Open Crosspoint
Digital Output
Clear Crosspoints
Delete Setup
Restore Defaults
Programmed Settling Time
Trigger
5-14
Dcccccccccccccc
DX
E0
En
F0
F1
G0
G1
G2 or G3
G4
G5
G6
G7
Hn
In
J0
K0
K1
K2
K3
K4
K5
Lbbb..X
M0
M1
M2
M8
M16
M32
M128
Nrc(,rc)...(,rc)
Onnn
P0
Pn
Qn
R0
Sn
T0 or T1
T2 or T3
T4 or T5
T6 or T7
T8 or T9
5.9.3
5.9.4
5.9.5
5.9.6
5.9.7
5.9.8
5.9.9
5.9.10
5.9.11
5.9.12
5.9.13
5.9.14
5.9.15
5.9.16
5.9.17
5.9.18
5.9.19
5.9.20
5.9.21
IEEE-488 Programming
Table 5-9 (cont.)
DDC summary
Mode
Command
Description
Para.
Status
Break/Make
Wabcdefgh
Execute
Terminator
X
Y0
Y1
Y2
Y3
Z0,n
Zn,0
Zm,n
Send machine status word
Send error status word
Output setup “s” (0-100) with present G format
Send RELAY STEP pointer
Send number of slaves
Send model number of each card in unit “u” (0-4)
Send relay settling time
Send digital input of unit (0-65535)
Send RELAY TEST input
Select rows for make/break operation (abcdefgh = 00000000
to 11111111)
Select rows for break/make operation (abcdefgh = 00000000
to 11111111)
Execute commands
<CR><LF>
<LF><CR>
<CR>
<LF>
Copy present relay setup to memory location “n” (1-100)
Copy setup from memory location “n” (1-100) to relays
Copy setup from location “m” (0-100) to location “n” (0-100)
5.9.22
Make/Break
U0
U1
U2,s
U3
U4
U5,u
U6
U7
U8
Vabcdefgh
Copy Setup
5.9.23
5.9.24
5.9.25
5.9.26
5.9.27
5-15
IEEE-488 Programming
5.9.2 A — External trigger
Purpose
Format
Parameters
To select which edge of an external trigger pulse initiates a trigger.
An
n=0
n =1
Falling edge triggers Model 707A
Rising edge triggers Model 707A
Default
Upon power-up or after receiving a DCL, SDC, or R0X command, the instrument defaults to A0
(falling edge).
Description
The An command lets you program the Model 707A for triggering on a TTL-compatible falling
or rising edge signal at the External Trigger input jack. A trigger signal increments the RELAY
STEP pointer and copies the setup indicated by the new value from memory to the relays.
Figure 5-8 shows example trigger pulses. Trigger on external must be the selected source
(T command), and triggers must be enabled (F command).
Programming note
Example
For information on the hardware this command is used with, refer to paragraph 4.11.
PRINT #1, “OUTPUT 18;A1X”
PRINT #1, “OUTPUT 18;A0X”
' Select rising edge pulse to trigger
' Select falling edge to trigger
Falling
Edge
TTL High
(3.4V Typical )
TTL Low
( 0.25V Typical )
600nsec
Minimum
A. FALLING EDGE OF PULSE
Rising
Edge
TTL High
(3.4V Typical )
TTL Low
( 0.25V Typical )
600nsec
Minimum
B. RISING EDGE OF PULSE
Figure 5-8
External trigger pulse
5-16
IEEE-488 Programming
5.9.3 B — Matrix ready
Purpose
Format
Parameters
To select the logic sense of the rear panel Matrix Ready signal.
Bn
n=0
n=1
Negative true Matrix Ready output
Positive true Matrix Ready output
Default
Upon power-up or after receiving a DCL, SDC, or R0X command, the instrument defaults to B0
(negative true).
Description
The B command lets you program the TTL-compatible Matrix Ready output as a high- or lowtrue signal. This signal goes false when the relays are switched; it goes true after completion of
the (hardware) relay settling time and (user) programmed settling time. Figure 5-9 shows example Matrix Ready signals.
Programming notes
1. The Matrix Ready signal is negated by anything that causes a change to a relay state even if
no relays actually change state (e.g., closing an already closed relay).
2. Changing the logic sense of the Matrix Ready signal does not change the logic sense of the
Matrix Ready bit in the serial poll byte.
Example
PRINT #1, “OUTPUT 18;B1X”
PRINT #1, “OUTPUT 18;B0X”
' Select positive true Matrix Ready
' Select negative true Matrix Ready
TTL High
( 3.4V Typical )
TTL Low
( 0.25V Typical )
Relay Settling Time +
Programmed Settling Time
A. MATRIX READY HIGH TRUE
TTL High
(3.4V Typical )
TTL Low
( 0.25V Typical )
Relay Settling Time +
Programmed Settling Time
B. MATRIX READY LOW TRUE
Figure 5-9
Matrix ready pulse
5-17
IEEE-488 Programming
5.9.4 C — Close crosspoint
Purpose
Format
To close crosspoints in a setup.
Crc(,rc)...(,rc)
Parameters
r = A to H Row designation of crosspoint
c = 1 to 360 Column designation of crosspoint (360 with maximum of five Model 707A units)
Description
The C command closes crosspoints in the setup indicated by the edit pointer. If the edit pointer
indicates the present relay setup (zero), the specified crosspoint relays are closed immediately.
If the edit pointer indicates a setup stored in memory (1-100), the specified crosspoints are set.
Programming notes
1. Do not include parentheses in command strings. They indicate that the option and associated
comma delimiter are optional.
2. Up to 25 crosspoints per mainframe can be specified in one close command (with a master
and four slaves, the limit is 125 crosspoints). In the same command string, up to 25 crosspoints per mainframe can be opened. If either limit is exceeded, an IDDCO results.
3. The maximum value of the column parameter depends on the configuration (72 for standalone, 360 for master with four slave units). An IDDCO results if the maximum value is
exceeded.
4. This command is equivalent to multiple light pen operation(s).
Example
PRINT #1, “OUTPUT 18;CA55X”
PRINT #1, “OUTPUT 18;CA55,A56,B49,B50X”
' Close one crosspoint
' Close multiple crosspoints
5.9.5 D — Display
Purpose
Format
Parameters
To write messages on the front panel alphanumeric display of a stand-alone or master unit.
Dcccccccccccccc
c = ASCII character (14 maximum)
Default
Upon power-up, or after receiving a DCL, SDC, or R0X command, the instrument defaults to
DX (return alphanumeric display to normal operation).
Description
The D command allows you to display messages on the front panel alphanumeric display of a
stand-alone or master Model 707A. To send a message, simply follow the D command with
appropriate ASCII characters. Many displayable ASCII characters can be sent, including numbers or upper case characters. Characters that can be displayed include: 0-9, A-Z, arithmetic and
most punctuation symbols.
Programming notes
1. As with other device-dependent commands, the D command string should be terminated with
the X.
2. Spaces in the command string are displayed.
3. The maximum number of characters is 14; any extra characters in the string are ignored. If
there are fewer than 14 characters between the D and X, the characters are left-justified and
the rest of the display is blank.
4. To return the alphanumeric display to normal, send DX, perform device clear, or return the
Model 707A to the local state.
Example
5-18
PRINT #1, “OUTPUT 18;DMODEL 707AX”
!Display MODEL 707A message
IEEE-488 Programming
5.9.6 E — Edit pointer
Purpose
Format
Parameters
To set the edit pointer
En
n=0
n=1 to 100
Present relay setup
Stored relay setup
Default
Upon power-up or after receiving a DCL, SDC, or R0X command, the instrument defaults to E0
(present relay setup).
Description
With the edit pointer, you can select which setup is affected by subsequent close (C) and open
(N) commands. This can be the present relay setup (zero) or one of the stored setups (1-100).
Programming notes
1. The edit pointer value is independent of the Relay Step and Memory Step values.
2. When using the edit pointer, it is not necessary to use the COPY key, because you are closing/
opening crosspoint relays or setting/clearing stored crosspoints directly and not just turning
on/off crosspoint LEDs.
Example
PRINT #1, “OUTPUT 18;E0X”
PRINT #1, “OUTPUT 18;E50X”
' Point to relays
' Point to stored relay setup 50
5.9.7 F — Enable/disable triggers
Purpose
Format
Parameters
To enable/disable triggers.
Fn
n=0
n=1
Disable triggers
Enable triggers
Default
Upon power-up or after receiving a DCL, SDC, or R0X command, the instrument defaults to F0
(triggers disabled).
Description
With the F command, you control whether the Model 707A responds to a trigger (from the external trigger connection or over the IEEE-488 bus). A trigger increments the Relay Step pointer
and copies the setup indicated by the new value from memory to the relays.
Programming notes
Example
It is good programming practice to disable triggers before changing the trigger source.
PRINT #1, “OUTPUT 18;F0X”
' Enable triggers
•
•
•
PRINT #1, “OUTPUT 18;F1X”
' Disable triggers
5-19
IEEE-488 Programming
5.9.8 G — Data format
Purpose
Format
Parameters
Default
Description
To select the output format of the data sent from the present relay setup or a setup stored in
memory.
Gn
n=0
n=1
n=2 or 3
n=4
n=5
n=6
n=7
Full output format, all data sent in one talk
Full output format, one row of one switching system per talk
Inspect output format, all data sent in one talk
Condensed output format, all data sent in one talk
Condensed output format, one switching system per talk
Binary output format, all data sent in one talk
Binary output format, one switching system per talk
Upon power-up or after receiving a DCL, SDC, or R0X command, the instrument defaults to G0
(full output format, all data sent in one talk).
Overview
The G command specifies the format of crosspoint data sent by the Model 707A over the IEEE488 bus in response to the U2 command. Data concerning the setup is sent by a “U2,n” command (either the present relay setup or a stored setup). You can control the data format and quantity sent. The full, condensed, and binary formats list the open or closed states of every
crosspoint in the setup; the inspect format shows only closed crosspoints.
G0, G1 = Full output format
With the G0/G1 full output formats, the open or closed states of all crosspoints in a setup are
sent in printable ASCII. An ASCII “-” represents an open crosspoint, and an ASCII “X” represents a closed crosspoint. For G0, all data is sent in one talk; for G1, the data from one row of
one switching system is sent per talk. An example of these formats is shown in Figure 5-10 for
the example setup of Table 5-10.
G2, G3 = Inspect output format
With the G2/G3 inspect output formats, the row/column address of each closed crosspoint in a
setup is sent in printable ASCII. An ASCII letter (A-H) represents a row, and an ASCII string of
up to two numbers (0-60) represents a column. Successive crosspoints are separated with a
comma. All data is sent in one talk. Figure 5-11 shows the formats of the example setup in Table
5-10.
G4, G5 = Condensed output format
The G4/G5 condensed output formats specify the states of all crosspoints with eight bits representing the eight crosspoints of a column. A set bit indicates a closed crosspoint. The hexadecimal representation of the binary value formed by these eight bits is sent as two printable ASCII
characters. For G4, all data is sent in one talk; for G5, the data from one switching system is sent
per talk. An example of these formats is shown in Figure 5-12 for the example setup of Table
5-10.
G6, G7 = Binary output format
The G6/G7 binary output formats specify the states of all crosspoints with an 8-bit group of bits
representing the eight crosspoints of a column. A set bit indicates a closed crosspoint. For G6,
5-20
IEEE-488 Programming
all data is sent in one talk; for G7, the data from one switching system is sent per talk. These
formats are shown in Figure 5-13 for the example setup of Table 5-10.
Table 5-10
Master/slave setup example
Unit
Closed crosspoints
Master
Slave 1
Slave 2
Slave 3
Slave 4
A1, A2, B3, B5, C7, C8, D9, D10, F11, F12
A13, A14, C15, C16, E17, E18
A25, A26, H27, H30, A36
A37, H38, H43, G48
G49, A50, A51, H55, H56, E57, E60
Obtaining data
Generally, data is placed into a string or numeric variable. For example, a typical input sequence
in BASIC is:
PRINT #1, “ENTER 18"
LINE INPUT #2, CROSSPOINT$
In this example, the complete crosspoint string is placed in the CROSSPOINT$ variable.
5-21
IEEE-488 Programming
Programming notes
1. Table 5-11 lists the number of bytes that are transmitted for the various data formats.
2. Since the data is transmitted in continuous strings (without carriage returns or line feeds), you
must format the data for display or printing legibility.
Table 5-11
Byte counts for data format
Stand-alone
Master with four slaves
Format
Bytes per
talk
Talks per
setup
Total
bytes
Bytes per
talk
Talks per
setup
Total
bytes
G0
G1
G2
G3
G4
G5
G6
G7
641
79 (Note 1)
(Note 2)
(Note 2)
154
154
76
76
1
9
1
1
1
1
1
1
641
641
(Note 2)
(Note 2)
154
154
76
76
3205
79 (Note 1)
(Note 2)
(Note 2)
770
154
380
76
1
45
1
1
1
5 (Note 3)
1
5 (Note 3)
3205
3205
(Note 2)
(Note 2)
770
770
380
380
Notes:
1. In addition, each unit is identified with a 9-byte ASCII string.
2. This value depends on the number of closed crosspoints.
3. Maximum of five talks, depending on number of slaves in the system.
SETUP 003
A
XX
XX
B
XX
C
XX
D
E
XX
F
G
H
SLAVE 001
A
XX
B
XX
C
D
XX
E
F
G
H
CARD 1 COLS.
Notes:
1. Slaves 2-4 have the same format as Slave 1.
2. Carriage returns and line feeds are not sent. They are shown here to improve readability.
3. Spacing between columns is one ASCII space.
Figure 5-10
G0 and G1 full output formats
5-22
CARD 6 COLS.
IEEE-488 Programming
A001,A002,B019,B020,C027,C028,D037,D038,F061,F062,A073,A074,C085,C086,E121,E122,A187,A188,
H205,H206,A223,A224,H265,H266,G301,G302,A313,A314,H337,H338,E355,E356
Note: Carriage returns and line feeds are not sent. They are shown here to improve readability.
Figure 5-11
G2 and G3 inspect output formats
MASTER
SLAVE 1
0003 00
010100000000
000000000000
000004040000
080800000000
000000000000
202000000000
XX
000000000000
020200000000
000000000000
000000000000
000000000000
000000000000
0003 01
010100000000
040400000000
000000000000
000000000000
101000000000
000000000000
XX
000000000000
000000000000
000000000000
000000000000
000000000000
000000000000
SETUP NUMBER (2 BYTES), UNIT NUMBER (1 BYTE)
CARD 1, COLS. 1-12
CARD 6, COLS. 61-72
CHECKSUM
Notes
1. Slaves 2-4 have the same format as that shown.
2. Carriage returns, line feeds, spaces, and blank lines are not sent. They are shown here to improve readability.
3. “XX” represents a 1-byte checksum value (hexadecimal) in printable ASCII.
4. The rows that correspond to the G4/G5 data are as follows:
G4/G5
Data
Corresponding
Row
00
01
02
04
08
10
20
40
80
none
A
B
C
D
E
F
G
H
Figure 5-12
G4 and G5 condensed output formats
5-23
IEEE-488 Programming
ROW H
MASTER
SLAVE 1
ROW A
SETUP NUMBER (2 BYTES),
UNIT NUMBER (1 BYTE)
00000000
00000001
00000000
00000000
00000010
00000000
00000000
00001000
00000000
00000000
00000000
00100000
00000000
XXXXXXXX
00000011
00000001
00000000
00000000
00000010
00000000
00000000
00001000
00000000
00000000
00000000
00100000
00000000
00000000
00000000
00000000
00000000
00000000
00000100
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000100
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000001
00000000
00000100
00000000
00000000
00000000
00000000
00000000
00010000
00000000
00000000
00000000
XXXXXXXX
00000011
00000001
00000000
00000100
00000000
00000000
00000000
00000000
00000000
00010000
00000000
00000000
00000000
00000001
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
00000000
COLS. 1-6
COLS. 7-12
COLS. 61-66
COLS. 67-72
CHECKSUM
CARD 1
CARD 6
Notes
1. Row A corresponds to the least significant bit of each 8-bit group, Row H to the most significant bit.
2. Slaves 2-4 have the same format as that shown.
3. Data is shown as the binary representation of 8-bit binary numbers. The binary value sent may not correspond to a printable
ASCII character.
4. Carriage returns, line feeds, spaces, and blank lines are not sent. They are shown here to improve readability.
5. "XXXXXXXX" represents an 8-bit checksum value in binary.
Figure 5-13
G6 and G7 binary output formats
5-24
IEEE-488 Programming
5.9.9 H — Hit key
Purpose
Format
Parameters
To allow emulation of front panel key press sequence.
Hn
The parameter “n” represents the number of the front panel key as shown in the following table.
Command Key
H1
H2
H3
H4
H5
H6
H7
H8
H9
H10
H11
H12
H13
H14
H15
H16
H17
H18
H19
H20
H21
Description
Programming notes
MEMORY
RELAYS
COPY DISPLAY → MEMORY
COPY DISPLAY → RELAYS
AUTOMATIC
SCROLL ▲
SCROLL ▼
INSERT
DELETE
MENU
SETTLING TIME
MAKE/BREAK
BREAK/MAKE
LOCAL
ENABLE
SOURCE
MANUAL
G
E
C
A
Command Key
H22
H23
H24
H25
H26
H27
H28
H29
H30
H31
H32
H33
H34
H35
H36
H37
H38
H39
H40
H41
H
F
D
B
7
4
1
0
8
5
2
CANCEL
9
6
3
ENTER
RESET
CLEAR
OPEN
CLOSE
The H command and its options allow you to emulate front panel keystroke sequences. To emulate any such sequence, simply send the appropriate commands in the necessary order.
1. The X character must follow each command in a multiple command string.
2. The H command is functional even if LLO (Local Lockout) is in effect.
5-25
IEEE-488 Programming
5.9.10 I — Insert blank setup
Purpose
Format
To insert a blank setup in memory.
In
Parameters
n=1 to 100
Description
During execution of this command, setups “n” through 99 are shifted up to the next highest location in memory (99 to 100, 98 to 99... n to n+1). Then, all crosspoints of setup “n” are cleared.
The front panel display is blanked during an insert operation.
Example
Stored relay setup
PRINT #1, “OUTPUT 18;I50”
' Insert blank setup at location 50
5.9.11 J — Self-test
Purpose
Format
To test ROM and RAM.
Jn
Parameters
n=0
Description
The self-test command starts execution of the ROM and RAM. If an error is detected, a RAM
FAIL or ROM FAIL message is displayed. Also, the self-test failed bit is set in the U1 error status
word (paragraph 5.9.22). Any front panel keypress or bus command overrides the message.
Programming notes
1. The value “n”, if sent, must be zero.
2. Allow approximately four seconds for the instrument to complete the self-test.
3. The instrument holds off bus operation with the NRFD line during self-test operation. Thus,
no commands can be sent during the self-test if hold-off on X is enabled.
Example
Perform self-test
PRINT #1, “OUTPUT 18;J0X”
' Perform self-test
5.9.12 K — EOI and hold-off
Purpose
Format
Parameters
Default
5-26
To enable/disable EOI and bus hold-off on X.
Kn
n= 0
n=1
n=2
n=3
n=4
n=5
Send EOI with last byte, hold-off on X until Ready
No EOI, hold-off on X until Ready
Send EOI with last byte, do not hold-off on X
No EOI, do not hold-off on X
Send EOI with last byte, hold-off on X until Matrix Ready
No EOI, hold-off on X until Matrix Ready
Upon power-up or after receiving a DCL, SDC, or R0X command, the instrument defaults to K0
(send EOI with last byte, hold-off on X until Ready).
IEEE-488 Programming
Description
The EOI line provides one method to positively identify the last byte in the data string sent by
the instrument. When enabled, EOI is asserted with the last byte the instrument sends over the
bus.
Bus hold-off allows the instrument to temporarily hold up bus operation via the NRFD line when
it receives the X character until all commands are processed. The advantage of using bus holdoff is that no commands are missed while the instrument is processing previously received commands. Typical hold-off times are discussed in paragraph 5.11.
Programming notes
Example
1. Some controllers rely on EOI to terminate their input sequences. Suppressing EOI may cause
the controller input sequence to hang.
2. When reading a buffer, EOI is asserted only at the end of the entire buffer transmission.
3. When enabled, EOI is asserted with the last byte in the terminator.
4. When bus hold-off is enabled, all bus activity is held up for the duration of the hold-off period,
not just for the duration of the communication with the Model 707A.
PRINT #1, “OUTPUT 18;K1X”
PRINT #1, “OUTPUT 18;K2X”
' No EOI, hold-off on X until Ready
' Send EOI with last byte, do not hold-off on X
5.9.13 L — Download setups
Purpose
Format
To download setups from the controller to the Model 707A.
Lbbbb...X
Parameters
bbbb... represents the G4/G5 or G6/G7 output string.
Description
This command downloads setup information in a G4/G5 or G6/G7 data format. It is used in conjunction with the U2 command (output setup data) to back up or expand the setups stored in the
Model 707A.
G formats are discussed in paragraph 5.9.8; see paragraph 5.9.22 for U commands.
Programming notes
Example
1. The data format for downloading is specified by the G format presently in effect.
2. The setup data string begins with a setup number and unit number and ends with a checksum
value.
3. The setup number is specified in a U2,n command (output setup “n”), as shown in the following programming example.
DIM SETUP$[32]
PRINT #1, “REMOTE 18"
PRINT #1, “OUTPUT 18;G4U2,1X”
PRINT #1, “ENTER 18"
LINE INPUT #2, SETUP$
PRINT SETUP$[1,6]
PRINT SETUP$[7,30]
PRINT SETUP$[31,32]
PRINT “PRESS ANY KEY TO CONTINUE”
DO
LOOP WHILE INKEY$= “ “
PRINT #1,”OUTPUT 18;”L”+SETUP$
+”X”18;”L”+SETUP$+”X”"
' Dimension for stand-alone
' Setup #1 in G4 format
' Get setup data
' Print setup and unit numbers
' Print setup data card by card
' Print checksum
' Inspect setup data
' Wait for keypress
' Download setup back to 707A
5-27
IEEE-488 Programming
5.9.14 M — SRQ and serial poll byte
Purpose
Format
Parameters
To program which conditions generate an SRQ (service request).
Mn
n=0
n=1
n=2
n=4
n=8
n=16
n=32
n=128
SRQ disabled
Not used
Not used
Not used
Matrix Ready
Ready for trigger
Error
Not used
Default
Upon power-up or after receiving a DCL, SDC, or R0X command, the instrument defaults to
M0 (SRQ disabled).
Description
The SRQ command selects which conditions cause the Model 707A to generate an SRQ (service
request). Once an SRQ is generated, the serial poll byte can be checked to determine if the
Model 707A was the instrument that generated the SRQ, and, if so, what conditions caused it.
The general format of the SRQ mask used to generate SRQs is shown in Figure 5-14. By sending
the appropriate M command, you can set the appropriate bit(s) to enable SRQ generation if those
particular conditions occur. Possible conditions are:
• A front panel key has been pressed (M2).
• An interrupt condition has been received at the Digital I/O port (M4).
• The Matrix Ready signal has been asserted (M8).
• The Ready (for trigger) signal has been asserted (M16).
• An error has occurred (M32). The nature of the error can be determined by reading the U1
error word as described in paragraph 5.9.22.
Decimal
Weighting
128
64
32
16
8
4
2
1
Bit Position
B7
B6
B5
B4
B3
B2
B1
B0
Not Used
S RQ 84
by 707A
(Serial Poll Byte Only)
Error
Ready for Trigger
Figure 5-14
SRQ mask and serial poll byte format
5-28
Not Used
Front Panel
Key Press
Digital I/O
Interrupt
Matrix Ready
IEEE-488 Programming
Serial poll byte
The general format of the serial poll byte is shown in Figure 5-14. Note that all bits except for
bit 6 correspond to the bits in the SRQ mask. These bits flag the following conditions:
Matrix ready (bit 3) — Set whenever the Matrix Ready signal is asserted. Cleared by the start of
relay switching.
Ready for trigger (bit 4) — Set when the Ready signal is asserted. This bit is cleared by:
• Receipt of X.
• Start of relay switching.
• Front panel keypress on master unit.
• Changing Make/Break or Break/Make row.
• Performing self-test.
• Pressing RELAYS key.
NOTE
Using the H command to “hit” keys could cause the Ready bit to cycle twice:
once when the H command is processed and again when the key press is
processed.
Error (bit 5) — Set if an error condition occurs. Cleared by reading the U1 error status word
(paragraph 5.9.22).
SRQ (bit 6) — Set if the Model 707A requests service via the SRQ line; cleared by a serial poll.
Programming notes
Example
1. The serial poll byte should be read once the instrument has generated an SRQ to clear the SRQ
line.
2. All bits in the serial poll byte latch when the instrument generates an SRQ.
3. If an error occurs, bit 5 (error) in the serial poll byte latches and remains so until the U1 word
is read (paragraph 5.9.22).
4. Multiple error conditions can be programmed by adding up the individual command values.
For example, send M12X for SRQ under matrix ready and digital I/O interrupt conditions.
PRINT
PRINT
PRINT
PRINT
#1,
#1,
#1,
#1,
"CLEAR 18"
"REMOTE 18"
"OUTPUT 18;M32X"
"OUTPUT 18;A2X"
WAITSRQ:
IF NOT(srq%()) THEN GOTO WAIT SRQ
PRINT #1, "SPOLL 18"
INPUT #2, S
PRINT "B7 B6 B5 B4 B3 B2 B1 B0"
FOR I=7 TO 0 STEP-1
PRINT BIT (S,I);
NEXT I
PRINT
PRINT #1, "OUTPUT 18;U1X"
PRINT #1, "ENTER 18"
LINE INPUT #2, ERROR$
PRINT ERROR$
' Program for SRQ on error
' Attempt to program invalid option
' Check interface status
' Wait for SRQ to occur
' Serial poll the instrument
' Read serial poll byte
' Label the bit positions
' Loop eight times
' Display the bit positions
' Program for error status
' Get U1 status to clear error
' Display error status
5-29
IEEE-488 Programming
5.9.15 N — Open crosspoint
Purpose
Format
To open crosspoints in a setup.
Nrc(,rc)...(,rc)
Parameters
r=A to H
c=1 to 360
Description
The N command opens crosspoints in the setup indicated by the edit pointer. If the edit pointer indicates the present relay setup (zero), the specified crosspoint relays are opened immediately. If the
edit pointer indicates a setup stored in memory (1-100), the specified crosspoints are cleared.
Programming notes
1. Do not include parentheses in command strings. They indicate that the option and associated
comma delimiter are optional.
2. Up to 25 crosspoints per mainframe can be specified in one open command (with a master
and four slaves, the limit is 125 crosspoints). In the same command string, up to 25 crosspoints per mainframe can be closed. If either limit is exceeded, an IDDCO results.
3. The maximum value of the column parameter depends on the configuration (72 for standalone, 360 for master with four slave units). An IDDCO results if the maximum value is
exceeded.
4. This command is equivalent to multiple light pen operation(s).
Example
Row designation of crosspoint
Column designation of crosspoint (360 with maximum of five Model 707A units)
' Open one crosspoint
' Open multiple crosspoints
PRINT #1, "OUTPUT 18;NA55X"
PRINT #1, "OUTPUT 18;NA55,A56,B49,B50X"
5.9.16 O — Digital output
Purpose
Format
Parameters
To set the states of the digital output lines.
Ovvv
vvv=000 to 255
Default
Upon power-up or after receiving a DCL, SDC, or R0X command, the instrument defaults to
O000 (all digital outputs set to logic low).
Description
This command is a decimal representation of the states of individual output lines of the digital
I/O port, where “1” is logic high and “0” is logic low. Bit assignments and corresponding connector pins are shown below:
Bit Position
Bit Weight
Digital
Programming notes
Example
5-30
Decimal value of digital output
7
128
8
6
64
7
5
32
6
4
16
5
3
8
4
2
4
3
1
2
2
0
1
1
1. In a master/slave configuration, only the output of the master unit is updated.
2. Leading zeros are not necessary in the parameter value.
3. This command is equivalent to a multiple light pen operation(s).
4. Output is negative true logic. Setting bit high will make output go low (sink).
PRINT #1, "OUTPUT 18;O15X"
PRINT #1, "OUTPUT 18;O0X"
' Set bits <3-0> high
' Restore default condition
IEEE-488 Programming
5.9.17 P — Clear crosspoints
Purpose
Format
To clear all crosspoints at the specified setup.
Pn
Parameters
n=0
n=1 to 100
Description
The P command clears all crosspoints in the setup indicated by its parameter. If the present relay
setup (zero) is specified, all crosspoint relays are opened immediately. If setup stored in memory
(1-100) is specified, all crosspoints of that setup are cleared.
Programming note
Example
Present relay setup
Stored relay setup
This command is equivalent to multiple front panel key presses.
PRINT #1, "OUTPUT 18;P0X"
PRINT #1, "OUTPUT 18;P20X"
' Open all relays
' Clear relay setup 20
5.9.18 Q — Delete setup
Purpose
Format
To delete a setup from memory.
Qn
Parameters
n=1 to 100
Description
During execution of this command, setups “n+1” through 100 are shifted down to the next lower
location in memory (“n+1” to “n”... 100 to 99). Then, all crosspoints of setup #100 are cleared.
The front panel display is blanked during a delete operation.
Programming note
Example
Stored relay setup
The command Q100 clears all crosspoints of relay setup 100.
PRINT #1, "OUTPUT 18;Q50X"
' Delete relay setup #50 from memory
5-31
IEEE-488 Programming
5.9.19 R — Restore defaults
Purpose
Format
To restore the Model 707A to factory default conditions.
Rn
Parameters
n=0
Description
An R0 command performs the following actions:
Restore factory defaults
• All setups stored in memory are cleared.
• Make/Break and Break/Make rows are cleared.
• A Device Clear operation (all crosspoint relays are opened, Relay Step pointer is set to 000,
Memory Step is set to 001).
DDC parameters are set to the values shown below:
A0
B0
E000
F0
G0
K0
M000
O000
S00000
T7
V00000000
W00000000
Y0
Programming note
Example
Initiate trigger on falling edge of External Trigger pulse.
Set Matrix Ready output signal to negative true.
Set edit pointer to present relay setup.
Disable triggers.
Set full output format, all data sent in one talk.
Send EOI with last byte, hold-off on X until ready.
Disable all SRQ sources.
Set all digital outputs to logic low.
Set user settling time to zero.
Trigger Model 707A on external trigger pulse.
De-select all rows for make/break.
De-select all rows for break/make.
Set terminator characters of <CR> <LF>.
The primary IEEE-488 address and master/slave operation are not affected by the Restore
command.
PRINT #1, "OUTPUT 18;R0X"
' Restore default conditions, clear setups
5.9.20 S — Programmed settling time
Purpose
Format
Parameters
5-32
To program the settling time.
Sn
n=0 to 65000
Time in ms
Default
Upon power-up or after receiving a DCL, SDC, or R0X command, the instrument defaults to S0
(programmed settling time of zero).
Description
With the S command, you can program the settling time (up to 65 seconds). The programmed
settling time starts after the longest relay settling time has elapsed.
IEEE-488 Programming
Programming notes
The total settling time equals the longest relay settling time of any card in the system plus any
user-programmed settling time. Figure 5-15 shows a timing diagram of the settling times.
Setup Data
Shift
Programmed
Settling Time
Relay
Settling
Ready
AA
AAAAAAA
Matrix
Ready
Not Settled
Message
TRIG
0verrun
Additional TRIGGER
not Processed
Additional Trigger is Processed
Figure 5-15
READY and MATRIX READY signal timing
Example
PRINT #1, "OUTPUT 18;S5000X"
PRINT #1, "OUTPUT 18;S0X"
' Program 5 second (5000 ms) settling time
' Restore default condition (0 ms)
5.9.21 T — Trigger
Purpose
Format
Parameters
To select the trigger source.
Tn
n=0 or 1
n=2 or 3
n=4 or 5
n=6 or 7
n=8 or 9
Trigger on talk
Trigger on GET
Trigger on X
Trigger on External Trigger pulse
Trigger on front panel MANUAL key
Default
Upon power-up or after receiving a DCL, SDC, or R0X command, the instrument defaults to T7
(Trigger on External Trigger pulse).
Description
With the trigger command, you can determine the trigger source over the bus or from an external
trigger pulse. A valid trigger increments the Relay Step pointer by one, stopping at 100, and copies the setup data indicated by the new value to the relays.
Programming notes
1. Duplication of trigger sources allows compatibility with other Keithley IEEE-488 instruction
sets.
2. Disabling triggers before changing the trigger source is a good programming practice.
3. If the unit is re-triggered while it is still processing a previous trigger, a Trigger Overrun or
Trigger Before Settling Time Expired error occurs, depending on when the additional trigger
occurs.
4. To trigger the instrument when using the trigger on talk, you must send the talk command
derived from the correct primary address. The factory default primary address is 18. Trigger
5-33
IEEE-488 Programming
on talk does not occur when the Model 707A becomes a talker, but rather as the controller
requests the first byte of data from the unit.
5. Trigger on GET allows the fastest IEEE-488 triggering response.
6. The X character that is sent when programming a trigger on X source triggers the instrument.
7. Front panel triggering with the MANUAL key is always enabled regardless of the programmed trigger source (while the TRIGGER ENABLE LED is lit); however, all front panel
keys are locked out if the unit is in remote (REMOTE on). To restore local operation in this
case, press the LOCAL key.
Example
PRINT #1, "OUTPUT 18;F0T0X"
PRINT #1, "OUTPUT 18;F1X"
PRINT #1, "ENTER 18"
LINE INPUT #2, A$
PRINT #1, "OUTPUT 18;F0T2X"
PRINT #1, "OUTPUT 18;F1X"
PRINT #1, "TRIGGER 18"
' Disable triggers, program trigger on talk.
' Enable triggers
' Trigger next setup
' Disable triggers, program trigger on GET
' Enable triggers
' Trigger next setup
5.9.22 U — Status
Purpose
Format
To obtain instrument status and system configuration.
Un
Un,s
Un,u
Parameters
n= 0
n=1
n = 2,s
n=3
n=4
n = 5,u
n=6
n=7
n=8
Description
Overview
Send machine status word.
Send error status word.
Output setup “s” (0-100) with present G format.
Send value of RELAY STEP pointer.
Send number of slaves.
Send ID of each card in unit “u” (0-4).
Send longest relay settling time.
Send digital input of unit.
Send RELAY TEST input.
By sending the appropriate U command and then addressing the instrument to talk as with normal data, you can obtain information on machine status, error conditions, and other data.
U0 Machine status word
The format of U0 is shown in Figure 5-16. The letters correspond to modes programmed by the
respective device-dependent commands. Returned values correspond to the programmed
numeric values. The values shown in Figure 5-16 are the default values.
5-34
IEEE-488 Programming
External Trigger Edge
Matrix Ready
Edit Pointer
Enable/Disable Triggers
Data Format
Hit Key
Model
Number
707 A0 B0 E000 F0 G0 HXX K0 M000 O000 S00000 T7 V00000000 W00000000 Y0 <TERM+EOI>
Terminator
Break/Make Rows
Make/Break Rows
Trigger Source
Programmed Settling Time
Digital Output
SRQ Mask
EOI and Hold-Off
Figure 5-16
U0 machine status word
U1 Error status word
The U1 command allows access to Model 707A error conditions. The error status word (Figure
5-17) is a string of ASCII characters representing binary bit positions. Reading the U1 status
clears the error bits. An error condition is flagged in the serial poll byte while any bits in the error
status word are set. The instrument can be programmed to generate an SRQ when an error condition occurs (see paragraph 5.9.14).
Model
Number
707 bbbbbbbbb <TERM+EOI>
IDDC
IDDCO
Not in Remote
Selftest Failed
Setup Checksum Error
Powerup Initialization Failed
Master / Slave Loop Error
Trigger Before Settling Time Expired
Trigger Overflow (Hardware)
Figure 5-17
U1 error status word
5-35
IEEE-488 Programming
The various bits in the U1 error status word are set when the following conditions are present:
IDDC — An invalid device-dependent command (IDDC) is received.
IDDCO — An invalid device-dependent command option (IDDCO) is received.
Not in Remote — An X command is received over the bus, but the Model 707A is not in remote.
Self-test Failed — The self-test detects a program ROM checksum error or a RAM error.
Trigger Overrun (Hardware) — A trigger is received before the Ready signal is asserted. The
trigger is ignored.
Trigger Before Settling Time Expired — A trigger is received before the Matrix Ready signal
is asserted. The trigger is processed.
Master/Slave Loop Error — There is a communication or timing error in the master/slave loop.
Power-up Initialization Failed — The power-up routine has detected a checksum error in the
information from one or more cards.
Setup Checksum Error — The power-up routine detects a checksum error in one or more setups stored in memory. (The affected setups are cleared.)
U2,n Formatted setup
With the U2 command, you can request the Model 707A to output data of either the present relay
setup (n = 0) or a stored setup (1 < = n < = 100) according to the G format presently in effect.
(See paragraph 5.9.8.)
U3 Relay step pointer
The U3 command (Figure 5-18) requests the value of the Relay Step pointer, which indicates the
last setup sent to the relays (000 < = nnn < = 100).
Identifier
RSP nnn <TERM+EOI>
000-100
Figure 5-18
U3 relay step pointer
U4 Number of slaves
With the U4 command (Figure 5-19), you can request the number of slaves present in a master/
slave loop configuration (between 1 and 4).
5-36
IEEE-488 Programming
Identifier
NOS n <TERM+EOI>
0-4
Figure 5-19
U4 number of slaves
U5,u Card IDs
By specifying a unit number in the U5 command (0 for master, 1-4 for slaves), you can request
the model numbers of the cards present in each mainframe. The output format is shown in Figure
5-20. The character string for an empty slot is “NONE”.
Identifier
CID0, 1,mmmmmm,2,mmmmmm3,mmmmmm,4,mmmmmm,5,mmmmmm,6,mmmmmm<TERM+EOI>
Model Number
Card Slot
Unit Number (0-4)
Figure 5-20
U5 card identification
U6 Relay settling time
The U6 command (Figure 5-21) requests the Model 707A to output the longest relay settling
time of all cards in the system (expressed in milliseconds).
Identifier
RSTnnnnn <TERM+EOI>
Milliseconds
Figure 5-21
U6 relay settling time
5-37
IEEE-488 Programming
U7 Digital input
The U7 command (Figure 5-22) requests a decimal value of the inputs at the digital I/O port. In
master/slave configurations, the digital input of the master unit is sent.
Identifier
DIN iii, <TERM+EOI>
Input (000-255)
Figure 5-22
U7 digital input
U8 Relay Test input
The U8 command (Figure 5-23) requests the status of the input pins at the Relay Test connector.
Values between 0 and 15 represent the status of pins 1 (LSB) through 4 (MSB).
Identifier
RTI nn
DIN
iii, <TERM+EOI
<TERM+EOI>>
Pins 1(000-255)
Through 4 (0-150)
Input
Pin 1 is LSB
Figure 5-23
U8 relay test input
Programming notes
5-38
1. The instrument transmits the appropriate status word only once each time the corresponding
U command is received.
2. To ensure that correct status is indicated, the status word should be requested immediately
after the command is transmitted. The status sent by the Model 707A is that which is present
at the time it is instructed to talk, not at the time the U command is received.
3. The bits in the U1 error status word latch and remain in that condition until the U1 word is
read.
4. The programmed terminator (default CR LF) is transmitted at the end of each status word.
Also, EOI is transmitted at the end (unless disabled with the K command).
5. If no U command has been received, the PRINT #1, “ENTER 18” and LINE INPUT #2, A$
commands request the letter (x) and number (nn) of the software revision for a stand-alone
unit or the master unit of a master/slave configuration (707Axnn). It is sent with two trailing
spaces plus the terminator and EOI.
IEEE-488 Programming
5.9.23 V — Make/break
Purpose
Format
To select rows for make/break operation.
Vabcdefgh
Parameters
abcdefgh= 00000000 All rows de-selected for make/break
to
11111111 All rows selected for make/break
Description
The V command selects individual rows for make/break (make-before-break) operation. A “1”
in the respective row field selects make/break; a “0” de-selects make/break operation.
Programming notes
1. Specifying fewer than eight numbers in the parameter field (e.g., V1111) is invalid. The
Model 707A takes no action on the rows and flags an IDDCO error.
2. The rows can be programmed for one of three switching options: make/break, break/make, or
don't care. A row cannot be selected for both make/break and break/make at the same time.
Selecting it for one de-selects it for the other.
3. When switching current sources, use make/break operation to keep current flowing and eliminate switching transients. When switching voltage sources, use break/make operation to
avoid momentary shorting of two paths together.
4. Given the present states and actions performed, the next states of the rows are listed below:
Present state
Action
Next state
Don't Care
Select Make/Break
De-select Make/Break
Select Make/Break
De-select Make/Break
Select Make/Break
De-select Make/Break
Make/Break
Don't Care
Make/Break
Don't Care
Make/Break
Break/Make
Make/Break
Break/Make
Example
PRINT #1, "OUTPUT 18;V11110000X" ' Select rows ABCD for make/break
PRINT #1, "OUTPUT 18;V00000000X" ' Restore default condition
5.9.24 W — Break/make
Purpose
Format
To select rows for make/break operation.
Wabcdefgh
Parameters
abcdefgh= 00000000 All rows de-selected for break/make
to
11111111 All rows selected for break/make
Description
The W command selects individual rows for break/make (break-before-make) operation. A “1”
in the respective row field selects break/make; a “0” de-selects break/make operation.
Programming notes
1. Specifying fewer than eight numbers in the parameter field (e.g., W1111) is invalid. The
Model 707A takes no action on the rows and flags an IDDCO error.
5-39
IEEE-488 Programming
2. The rows can be programmed for one of three switching options: make/break, break/make, or
don't care. A row cannot be selected for both make/break and break/make at the same time.
Selecting it for one de-selects it for the other.
3. When switching current sources, use make/break operation to keep current flowing and eliminate switching transients. When switching voltage sources, use break/make operation to
avoid momentary shorting of two paths together.
4. Given the present states and actions performed, the next states of the rows are listed below:
Present State
Action
Next State
Don't Care
Select Break/Make
De-select Break/Make
Select Break/Make
De-select Break/Make
Select Break/Make
De-select Break/Make
Break/Make
Don't Care
Break/Make
Make/Break
Break/Make
Don't Care
Make/Break
Break/Make
Example
PRINT #1, "OUTPUT 18;W11110000X"
PRINT #1, "OUTPUT 18;W00000000X"
' Select rows ABCD for break/make
' Restore default condition
5.9.25 X — Execute
Purpose
Format
To direct the Model 707A to execute device-dependent commands received since the last X.
<command> X
Description
The execute command is implemented by sending an ASCII X over the bus. Its purpose is to
direct the Model 707A to execute other device-dependent commands. Generally, the execute
character is the last byte sent in the command string; however, there may be some cases when it
is desirable to send a string of characters at one time and then send the execute character later on.
Programming notes
1. Commands or command strings sent without the X character are not executed at that time, but
they are stored in an internal command buffer for later execution once the X character is
finally received.
2. The X character can also be used to trigger, as described in paragraph 5.9.21.
3. Commands are not necessarily executed in the order sent (see Table 5-8). To force a particular
command sequence, include the X character after each command in the command string.
Example
5-40
PRINT
PRINT
PRINT
PRINT
PRINT
#1,
#1,
#1,
#1,
#1,
"OUTPUT
"OUTPUT
"OUTPUT
"OUTPUT
"OUTPUT
18;E1X"
18;E1CA47X"
18;T6XA1XR1X"
18;G2Y1"
18;X"
' Execute single command
' Execute multiple commands
' Force command sequence
' Send string without execute
' Now execute command string at later time
IEEE-488 Programming
5.9.26 Y — Terminator
Purpose
Format
Parameters
To select the ASCII terminator sequence that marks the end of the instrument's data string or status word.
Yn
n = 0 <CR><LF>
n = 1 <LF><CR>
n = 2 <CR>
n = 3 <LF>
Default
Upon power-up or after receiving a DCL, SDC, or R0X command, the instrument defaults to Y0
(<CR><LF>).
Description
By using the Y command, you can program the number and type of terminator characters the
instrument sends at the end of its data string. Available terminator characters are the commonly
used CR (carriage return, ASCII 13) and LF (line feed, ASCII 10) characters. These terminator
characters are recognized by most controllers.
Programming notes
1. EOI is another method that can be used to terminate the controller input sequence, as discussed in paragraph 5.9.12. EOI is asserted with the last terminator byte when enabled.
2. The programmed terminator is sent at the end of the transmission each time the Model 707A
is addressed to talk, regardless of the selected data format.
3. Status word programming is covered in paragraph 5.9.22
PRINT #1, "OUTPUT 18;Y2X"
' Terminator on CR
PRINT #1, "OUTPUT 18;Y0X"
' Restore default
5.9.27 Z — Copy setup
Purpose
Format
Parameters
To copy a setup from relays or memory to relays or memory.
Zm,n
m = 0-100
n = 0-100
Copy present relay setup from...
Copy present relay setup to...
0,n = Copy present relay setup to stored setup “n” (1-100)
n,0 = Copy stored setup “n” (1-100) to present relay setup
m,n = Copy setup “m” (0-100) to setup “n” (0-100)
Description
By specifying a source and destination in the Z command, you can copy data between stored
setups and between the relays and setups stored in memory. Copying a setup to the relays sets
the Relay Step pointer to that setup.
Programming note
The Z0,0X command sends the present relay setup to the relays. There is no effect on the relays,
but the Relay Step pointer will be reset to 000.
Example
PRINT #1, "OUTPUT 18;Z0,10X"
PRINT #1, "OUTPUT 18;Z20,0X"
PRINT #1, "OUTPUT 18;Z10,20X"
' Copy present relay setup to setup 10
' Copy setup 20 from memory to relays
' Copy setup 10 to setup 20
5-41
IEEE-488 Programming
5.10 Relay command combinations
There are four device-dependent commands that have an immediate effect on relay states:
• E0N... — Point to relays, open specified crosspoints.
• E0C... — Point to relays, close specified crosspoints.
• P0 — Open all relays.
• Zn,0 — Copy setup “n” to relays.
Combinations of these commands in the same command string cause only one relay switching operation when the X character
is received. The command hierarchy (E, P, Z, N, C) determines the final data that is sent to the relays. This is shown in the following examples.
Example 1
The command string “E0P0CA1X” sets the edit pointer to the present relay setup, opens all relays, and closes crosspoint A1.
A1 will be the only closed crosspoint.
Example 2
The string “E0Z5,0CA1X” sets the edit pointer to the relays, copies stored setup #5 to the relays, and closes crosspoint A1. A1
will be closed regardless of the state of A1 in setup #5. The status of the relays will be a combination of setup #5 and a closed
A1 crosspoint.
Example 3
The command string “E0Z5,0NA1X” points to the relays, copies setup #5 to the relays, and opens crosspoint A1. If setup #5
had specified A1 to be closed, the command NA1 overrides that. (A1 will not close, then open, as there will be only one relay
switching operation.) The relays will reflect setup #5 and an open A1 crosspoint.
5-42
IEEE-488 Programming
5.11 Timing considerations
Timing considerations for IEEE-488 programming include:
• Data transfer rates between the controller and Model 707A (stand-alone or master) over the IEEE-488 bus.
• Command string parse time within the stand-alone or master unit.
• Data transfer rates among the units in a master/slave loop.
• Execution times of the tasks defined by device-dependent commands.
The times needed for these actions are determined by the length of the command string, the number of units in a master/slave
configuration, the types of commands, and the speed of the controller.
Typically, a command string sent to the Model 707A will transmit at a rate of four characters per millisecond. (Assuming the
transfer speed of the controller does not affect the listening rate of the Model 707A.) For example, the CA1,CA5X command
string will take 2ms to transmit from the controller to the Model 707A.
When the Model 707A is sending data to the controller (e.g., uploading setup data), the transmission rate will typically be 2.5
characters per millisecond.
The bus hold-off time for each command is the time from receipt of the “X” to “instrument configured.” It includes the parsing
time, data transfers within a master/slave loop, and command execution time.
Table 5-12 summarizes the total times (transmission plus hold-off) for device-dependent commands acting on a stand-alone
unit. Table 5-13 summarizes these times for a master and one slave system. Bus hold-off times for individual command strings
can be calculated by subtracting the transmission time (four characters per millisecond).
5-43
IEEE-488 Programming
Table 5-12
Typical transmission and hold-off times — stand-alone
Description
Command
Time
External Trigger
Matrix Ready
Close Crosspoint(s)
A0X
B0X
CA1X
CA1X
CA1,H72X
CA1,H72X
D**************X
DX
E0X
E100X
F0X
G7X
H5X
I1X
I100X
J0X
K0X
Lbbb...X
M32X
4.8ms
4.8ms
18.6ms
19.9ms
21.7ms
23.1ms
10.6ms
3.8ms
4.4ms
5.8ms
4.8ms
4.4ms
5.3ms
835ms
1.1ms
3.3ms
4.4ms
56.0ms
4.9ms
O255X
P0X
P55X
Q1X
Q100X
R0X
S0X
S65000X
T7X
U0X
U2,100X
V00000000X
V11111111X
V00001111X
5.8ms
18.9ms
20.5ms
828ms
21.0ms
628ms
5.0ms
7.3ms
4.8ms
4.5ms
6.8ms
124ms
134ms
153ms
X
Y0X
Z0,0X
Z0,100X
Z100,99X
3.2ms
4.7ms
21.1ms
23.3ms
21.6ms
Display
Edit Pointer
Enable/Disable Triggers
Data Format
Hit Key
Insert Blank Setup
Self-test
EOI and Hold-off
Download Setup
SRQ
Open Crosspoint(s)
Digital Output
Clear Crosspoints
Delete Setup
Restore Defaults
Programmed Settling Time
Trigger Source
Status
Make/Break Rows
Break/Make Rows
Execute
Terminator
Copy Setup
5-44
Notes
To relays
To setup 55
To relays
To setup 55
Binary format (G6,G7)
Similar to Close Crosspoints (“C”) times
With no B/M rows set
With no B/M rows set
With A,B,C,D as B/M
Similar to Make/Break Rows (“V”) times
IEEE-488 Programming
Table 5-13
Typical transmission and hold-off times — master and one slave
Description
Command
Time
External Trigger
Matrix Ready
Close Crosspoint(s)
A0X
B0X
CA1X
CA73X
CA1,A73X
D**************X
E0X
E55X
F0X
G0X
I1X
I100X
J0X
K0X
Lbbb...X
M32X
12.3ms
12.3ms
31.5ms
48.7ms
51.0ms
17.3ms
17.4ms
18.8ms
18.5ms
11.7ms
1.7s
49.9ms
3.4ms
11.6ms
68.5ms
12.0ms
O255X
P0X
P55X
Q1X
Q100X
R0X
S0X
S65000X
T7X
U0X
U2,100X
V00000000X
V11111111X
V00001111X
12.9ms
47.8ms
48.8ms
1.7s
49.8ms
1.4s
11.9ms
14.6ms
12.3ms
11.8ms
14.2ms
265ms
284ms
324ms
10.5ms
11.5ms
51.1ms
47.2ms
55.4ms
49.9ms
Display
Edit Pointer
Enable/Disable Triggers
Data Format
Insert Blank Setup
Self-test
EOI and Hold-off
Download Setup
SRQ
Open Crosspoint(s)
Digital Output
Clear Crosspoints
Delete Setup
Restore Defaults
Programmed Settling Time
Trigger Source
Status
Make/Break Rows
Break/Make Rows
Execute
Terminator
Copy Setup
Notes
Binary format (G6,G7)
Similar to Close Crosspoints ("C) times
X
Y0X
Z0,0X
Z0,100X
Z100,99X
With no B/M rows set
With no B/M rows set
With A,B,C,D as B/M
Similar to Make/Break Rows (“V”) times
5-45
6
Principles of Operation
6.1
INTRODUCTION
This section contains a functional description of the Model
707A in block diagram form as well as details of the various
sections of the instrument. Information is arranged to
provide a description of each of the functional blocks within
the instrument. Many of these descriptions include
simplified schematics and block diagrams. Component
layout drawings are located at the end of Section 8.
6.2
Overall function description
The Model 707A mainframe contains three circuit boards,
primarily digital, and a power supply. Relay switching cards
that plug into the mainframe have analog circuits for signal
paths and digital circuits for control. Figure 6-1 shows the
interconnection of the mainframe's digital board, front panel
display board, and backplane in a block diagram.
The following paragraphs describe Model 707A circuitry by
function, with some functions residing on more than one
board (e.g., relay control circuits and display circuits).
6.3
Microcomputer
The Model 707A is controlled by an internal microcomputer.
As shown in the block diagram of Figure 6-2, the digital
board contains the CPU, memory, and associated components:
• 68B09 microprocessor (U6)
• Oscillator (Yl)
• Power-up reset (U17)
• Address decoding PALs (U1, U2)
• 32Kx8-bit EPROM (U7)
• 32Kx8-bit RAM (U8) with battery back-up (BT1, U3)
The microcomputer centers around the 8-bit 68B09 microprocessor. The MPU has direct control over relay switching,
front panel displays and switches, and rear panel interfaces
(master/slave, digital I/O, IEEE-488 bus, and triggers).
Although the 68B09 microprocessor will operate at frequencies up to 8MHz, a clock frequency of 7.15909MHz is used
to reduce interference with instruments that use measurement signals with harmonics of 1MHz. Crystal Yl provides
timing for the microprocessor. Internally, the clock frequency is divided down by four to obtain an operating frequency on the microprocessor bus of 1.78977MHz.
6.3.1 Reset circuit
The reset circuit, which is based on an 8211 (or 6728) voltage detector (U17), senses the output of the power supply.
When the output drops below approximately 4.6V, the 8211
asserts the RESET (low true) line. Two 1% resistors (R34
and R35) form a voltage divider, which is calibrated to match
the comparator threshold voltage of the 8211 by either
removing or leaving in R36, which is in parallel with R35.
During power-off or brownout conditions, the RESET line
must be asserted before the power supply drops into the comparator threshold range (4.25 to 4.5 volts) of the DS-1210
non-volatile RAM controller (U3). During power-up, capacitor C91 is charged up to delay the RESET line going high
for 110 to 260msec.
6-1
Principles of Operation
6.3.2 Address decoding
U1, a 16P8A programmable array logic (PAL) chip, decodes
microprocessor address lines A15-A12 for the 32K EPROM
($8000-$FFFF) and the 32K bytes of bank-selected RAM
($0000-$2FFF). Bank selection is used so that the RAM
appears as 12K bytes of address space to the microprocessor.
U1 also decodes the three bank-select lines (BS3-BS0) from
the PB6-PB4 outputs of U9, a 6522A versatile interface
adapter (VIA). The RAM is decoded as 8K bytes ($0000$1FFF) and six 4K byte banks, which appear to the microprocessor at addresses $2000-$2FFF. This permits the
microprocessor to select one of the six 4K byte banks.
Master/
Slave
Digital
I/O
Digital Board
Display
Board
IEEE-488
External Trigger In
Light
Pen
Matrix Ready Out
Relay Test
Backplane
Up to 6 Plug-in Matrix Cards
Figure 6-1
Model 707A block diagram
6-2
Principles of Operation
CPU
Battery
Backup
32Kx8
RAM
32Kx8
EPROM
BLANK
Display
Board
Interface
IRQ
DISPCLK
DISPDATA
KEYCLK
FIRQ
KEYDATA
System
Tick
Timer
LPSWITCH
Light Pen
Interface
LPRESET
SENSEPULSE
LPSENSE
Data out
6
Card Select
Matrix
Card
Interface
RELAYDATA
CLK
Master/
Slave
Interface
Data in
Ready
M/S TRIGGER
LPSENSE
STROBE
LPRESET
CLRADDR
NEXTADDR
SLAVE
M/S TRIGGER
IDDATA
Trigger
MUX
Logic
Level
Inputs
4
Relay
Test
Interface
EXTERNAL TRIGGER
8
Digital
I/O
2
8
Outputs
OUTPULSE
Inputs
INLATCH
IEEE-488
Matrix
Ready
Interface
MATRIX READY
Figure 6-2
Digital board block diagram
6-3
Principles of Operation
Address decoding for peripheral devices on the microprocessor bus is performed by another 16P8A PAL (U2). Peripheral devices are decoded at 16-byte intervals in the address
range of $3800-$38FF. These include, for example, a
6522A-VIA, a 65C21 peripheral interface adapter (PIA), and
a 68B50 asynchronous communication interface adapter
(ACIA).
6.3.3 Memory
The 32K bytes of instrument operation software are stored in
U7, which is a 27256 EPROM. The revision level of the software is displayed on power-up.
U8 is a 32K byte static CMOS RAM chip that is used for
storing relay setups and as a scratchpad during normal operation. Its power source and chip enable lines are routed
through U3, a DS-1210 NVRAM controller. Figure 6-3
shows a simplified schematic of the RAM and battery backup circuitry.
The NVRAM controller performs the functions of switching
the RAM power source between Vcc and the lithium battery
(BT1). It also disables chip enable (CE) to the RAM when
Vcc is outside the specified limits. (See the paragraph
describing the reset circuitry.)
6-4
In addition, if the battery power goes below a specified limit
while Vcc is not present, a DS-1210 chip normally inhibits
the second chip enable signal to the RAM after Vcc is
restored. Since this feature is not used in the Model 707A,
the software always does a dummy read of memory locations
$0000-$0001 on power-up to get past the second chip enable
cycle. This permits the Model 707A to operate properly with
no battery, or if the battery has been replaced.
6.4
Relay control circuitry
The relay control circuits reside on the backplane board, digital board, and each switching card.
The backplane board acts as a passive conduit for:
• Control signals from the digital board to the switching
cards and response from the switching cards to the
digital board.
• Power lines to the switching cards.
• Expansion of analog signals among the switching
cards.
Operations of relay control circuitry on the digital board and
a typical switching card are described in the following
paragraphs.
Principles of Operation
U103
+5V
U114
6522A
VIA
DS-1210
PB4 BS0
BS1
PB5
BS2
PB6
CE
VCC I
CE0
VCCO
VBAT2
GND
U117
BT1
16P8A
I7
O7
U104
I8
U106
68B09
I9
8832C20
A15
I3
A14
A13
A12
I4
CE
I5
I6
O4
O5
O6
A11
A10
A9
A8
A7
A6
A5
A4
A3
A2
A1
A0
Vcc
OE
A14
A13
A12
A11
A10
A9
A8
A7
A6
A5
A4
A3
A2
A1
A0
Figure 6-3
RAM and battery backup
6-5
Principles of Operation
6.4.1 Switching card interface
A simplified schematic and timing diagram of the digital
board's switching card interface are shown in Figures 6-4 and
6-5.
The microprocessor reads card identification data from the
EPROM on each installed card during power-up, and also
sends relay control data to the cards during the course of
operation. This data is sent and received in serial form.
On the digital board, U25, U26, US, U22, and U24 form an
8-bit parallel-in, serial out data converter. When the microprocessor executes a write to the address decoded for U25 (a
74HCT165 shift register), the data bus contents are loaded
into U25, and all ones are loaded into U26 (another
74HCT165) causing its output OH to go high.
At the end of the write cycle, the SELECT RELAYDATA
decode line goes high, causing the output of the U5
(74HCT08) AND gate to go high. This signal (ACTIVE)
gates the microprocessor E clock through a U22 (74HCT00)
6-6
NAND, which is buffered by U28 and sent to the cards as the
CLK signal. Clock cycles are counted by the U26 shift register. After 8 cycles, OH of U26 returns low, disabling further
CLK pulses.
The U24 (74HCT74) flip-flop and another U22 NAND gate
are used to create an inverted version of CLK, which does
not start until after one cycle of CLK. This signal is used to
shift data out of the U25 RELAYDATA shift register.
6.4.2 Switching card logic
See Figure 6-6 for a block diagram of the logic on a typical
switching card.
On the cards, the CLK and RELAYDATA signals are buffered and sent to a string of UCN-5841 serial input latched
driver chips. The CLK signal is sent in parallel to all of the
driver ICs and the serial data out of one driver is connected
to the serial data in of the next.
Principles of Operation
U12
HCT374
D7
68B09
Data
Bus
U2
16P8A
O3
SELECT CARDSEL
O2
N.C.
U25
D0
+5V
H
IN
D0
6D
6Q
5D
5Q
4D
4Q
3D
3Q
2D
2Q
1D
1Q
STROBE
CARD 6
CARD 5
CARD 4
CARD 3
CARD 2
CARD 1
H
IN
G
F
E
7Q
HCT165
G
68B09
Data
Bus
8Q
7D
U26
HCT165
D7
8D
F
OH
E
D
D
C
C
B
B
A
A
U5
ACTIVE
OH
U22
U28
CLK
E HCT00
U24
HCT08
+5V
U22
HCT74
D
HCT244
Q
HCT00
SH/LD
SH/LD
U28
RELAYDATA
HCT244
CLR
SELECT RELAY DATA
+5V
U9
U27
VIA
PA 7
PA 6
PA 5
PA 4
PA 3
PA 2
PA 1
PA 0
HCT164
ID 7
ID 6
ID 5
ID 4
ID 3
ID 2
ID 1
ID 0
H
G
F
U28
IDDATA
IN A
HCT244
IN B
E
D
C
B
A
U28
PB3
PB2
U28
CLRADDR
NEXTADDR
HCT244
Figure 6-4
Switching card interface simplified schematic
6-7
Principles of Operation
E
SELECT RELAYDATA
ACTIVE
U24 OUTPUT Q
8th Rising Edge
CLK
RELAY DATA
D7
D6
D5
D4
D3
D2
D1
D0
etc.
U25 CLK
Figure 6-5
Switching card interface timing diagram
8KX8
EPROM
PARALLEL TO
SERIAL
8
DATA
IN
BUFFER
NEXT ADRS
CLOCK
OUT
ADRS
CLK
IDDATA
12
RELAY DATA
12-BIT
COUNTER
ENABLE
CLOCK
CLEAR
SELECT
CLEAR ADRS
CLOCK
IDDATA
STROBE
CLOCK
RELAY DATA
IN
SERIAL TO PARALLEL
RELAY DRIVERS
ENABLE
POWER ON
RESET
CLR
Figure 6-6
Typical switching card logic block diagram
6-8
STROBE
OUT
n card-specific
RELAYS
Principles of Operation
ID data circuits
3. The NEXTADDR line (PB2 of VIA) is set low. This
increments the counter and enables parallel loading of
the
parallel-to-serial
converter
(74HCTI65).
NEXTADDR is kept low long enough for the counter to
increment and the EPROM outputs to stabilize. This
sequence functions because the LOAD input of the
parallel-to-serial converter is level-sensitive rather than
edge-sensitive. The first EPROM address used by the
Model 707A is location one, not zero.
4. The same CLK signal that shifts RELAYDATA into the
relay driver also clocks the parallel-to-serial converter to
shift all eight data bits from the converter to the digital
board via the IDDATA line. (This means that a byte of
RELAYDATA must be sent to a card to get the next byte
of IDDATA.)
Each card has a 2764 EPROM that contains the following
identification data:
• Card model number
• Relay (hardware) settling time
• Relay configuration table
The configuration table defines the location of each relay
driver within the serial RELAYDATA bit stream. The table is
necessary because the physical layout of cards varies. In
addition, the table accommodates row and/or column isolation relays, such as those on the Model 7072 card.
To read this ID data, the sequence below is performed upon
power-up. Figure 6-7 shows the general timing of this
sequence.
Steps 3 and 4 are repeated until all the necessary EPROM
locations are read.
1. The CARDSEL line is brought low, enabling the
EPROM outputs. This line remains low throughout the
ID data transmission sequence.
2. The CLRADDR line (generated by port signal PB3 of
the digital boards VIA) is pulsed high to clear the 12-bit
address counter (74HCT4040) to zero. At this point, an
EPROM address of zero is selected. This pulse occurs
only once.
As seen in Figure 6-4 of the digital board, IDDATA is converted back to parallel by U27 (74HCTI64) and is read by the
microprocessor through the port A lines of U9 (6522A VIA).
CARDSEL
CLRADDR
NEXTADDR
CLK
Figure 6-7
IDDATA timing diagram
IDDATA
D7
D6
D5
D4
D3
D2
D1
D0
6-9
Principles of Operation
Relay control
NOTE
The STROBE signal can be high or low on
power-up since the outputs of U12
(74HCT374) on the digital board are
undefined at power-on. Since a falling
edge on STROBE, after the Output Enable
circuit times out, enables the relay driver
outputs, the power-up software must set
STROBE low before the time-out. It then
pulses STROBE high only after the relay
driver shift registers have been cleared.
The CLK, RELAYDATA, and IDDATA lines are bused to all
six card slots on the backplane board. A separate card select
signal is sent to each card to enable it for receiving RELAYDATA and sending IDDATA. The microprocessor controls
the card select signals through U12 (74HCT374) on the digital board, which is decoded as an output port on the microprocessor bus.
The relays are controlled by the serial data transmitted via
the RELAYDATA lines. Bytes for each card are shifted serially into latches located in the relay drivers. The serial data
is fed in through the DATA lines under control of the CLK
signal. As data overflows one register, it is fed out the Q’S
line of that register to the next IC down the chain.
Once all the bytes have been shifted into each card in the
mainframe, the STROBE line is set high to latch the relay
information into the Q outputs of the relay drivers, and the
appropriate relays are energized (assuming the driver outputs
are enabled, as discussed below). Logic convention is such
that the corresponding relay driver output must be low to
energize the associated relay, while the output is high when
the relay is de-energized. The STROBE signal is received by
all cards regardless of the state of their respective card select
lines.
Power-on safeguard
Each card has a power-on safeguard circuit to ensure that
relays do not randomly energize upon power-up. Two NAND
gates of a 74HCT00 are configured as an R-S flip-flop. On
power-up, the Q output of the flip-flop is set high, holding the
low true OEN (output enable) pins of the relay drivers high.
Hence, the driver outputs are disabled and all relays remain
de-energized regardless of the relay data information present
at that time.
The falling edge of the first STROBE pulse that comes along
(to load relay data) clears the R-S flip-flop, setting the OEN
pins low and enabling the driver outputs. (At this time, valid
relay control data has been sent to the cards and is present in
the latches of the driver chips.) This action allows the relays
to be controlled by the transmitted relay data information.
6-10
A hold-off period (typically 470msec) is included in the safeguard circuit to guard against premature enabling of the
relays. The time constant of the hold-off period is determined by an R-C network.
6.5
Display circuitry
Model 707A display circuitry includes components needed
to control the alphanumeric display, front panel annunciator
LEDs, crosspoint LEDs, make/break and break/make LEDs,
and needed to read front panel switches.
The display circuitry resides on the display board and digital
board. See Figure 6-8 for a block diagram of the display
board and Figure 6-9 for a simplified schematic of the display board interface on the digital board.
The front panel display is multiplexed as 15 columns of up
to 63 segments each:
• There are 14 columns of alphanumeric display digits,
plus a 15th column containing the discrete annunciator
LEDs (TALK, LISTEN, REMOTE, MEMORY,
RELAYS, etc.).
• There are 12 columns of crosspoint display LEDs. They
line up under the right-most 12 alphanumeric digits.
• There is one column of Make/Break and Break/Make
LEDs. It lines up under the column containing the discrete annunciators.
The first 15 display segments are the 14-segment plus decimal point alphanumeric digits (in columns 1-14), or the discrete annunciators (in column 15). The remaining 48 display
segments are divided into six groups of eight, one group for
each block of crosspoint displays (for columns 1-12), or for
the Make/Break and Break/Make LEDs (for column 15).
Segment assignments for the multiplexed columns are
shown in Table 6-1.
Principles of Operation
SOURCE DRIVERS
14-SEGMENT DISPLAYS
U11U12
15
DISCRETE
LEDS
14
9
1
U1U2 SINK DRIVERS
LED
ARRAY
DISPDATA
8
8
LED
ARRAY
LED
ARRAY
SOURCE
DRIVERS
8
8
8
U13U18
LED
ARRAY
LED
ARRAY
LED
ARRAY
8
12
12
U3-U5 SINK DRIVERS
15
12
KEY ARRAY
6
7
U27
U28
DIGIT DECODE
SHIFTREG
KEYDATA
KEYDATA
KEYCLK
KEYCLK
U20
DISPDATA
LOAD
4
SHIFT REG
DISPDATA
DISPCLK
BLANK
Figure 6-8
Display board diagram
6-11
Principles of Operation
Table 6-1
Display segment assignments
Display
Segments
1-15
16-23
24-31
32-39
40-47
48-55
56-63
Display
Segments
1-15
16-23
24-31
32-39
40-47
48-55
56-63
Display MUX Columns
15
13
12
11
Annunciator Alphanumeric Alphanumeric Alphanumeric Alphanumeric
digit 2 DS1
digit 3 DS2
digit 4 DS2
digit 1 DS1
LEDs
(MSD)
DS32-DS40
Card 1
Card 1
Upper make/
column 2
column 1
break LEDs
DS8-DS9
DS8-DS9
DS8-DS9
Card 2
Card 2
column 2
column 1
DS12-DS13 DS12-DS13
Card 3
Card 3
Upper break/
column 2
column 1
make LEDs
DS16-DS17 DS16-DS17
DS18-DS19
Card 4
Card 4
Lower make/
column 2
column 1
break LEDs
DS20-DS21 DS20-DS21
DS20-DS21
Card 5
Card 5
column 2
column 1
DS24-DS25 DS24-DS25
Card 6
Card 6
Lower break/
column 2
column 1
make LEDs
DS28-DS29 DS28-DS29
DS30-DS31
10
9
7
6
5
4
3
8
Alphanumeric Alphanumeric Alphanumeric
digit 5 DS3
digit 6 DS3
digit 7 DS4
Card 1
column 3
DS8-DS9
Card 2
column 3
DS12-DS13
Card 3
column 3
DS16-DS17
Card 4
column 3
DS20-DS21
Card 5
column 3
DS24-DS25
Card 6
column 3
DS28-DS29
Card 1
column 4
DS8-DS9
Card 2
column 4
DS12-DS13
Card 3
column 4
DS16-DS17
Card 4
column 4
DS20-DS21
Card 5
column 4
DS24-DS25
Card 6
column 4
DS28-DS29
2
1
Display MUX columns
Alphanumeric Alphanumeric Alphanumeric Alphanumeric Alphanumeric Alphanumeric Alphanumeric
digit 8 DS4
digit 9 DS5 digit 10 DS5 digit 11 DS6 digit 12 DS6 digit 13 DS7 digit 14 DS7
(LSD)
Card 1
Card 1
Card 1
Card 1
Card 1
Card 1
Card 1
column 6
column 7
column 8
column 9
column 10
column 11
column 12
DS10-DS11 DS10-DS11 DS10-DS11 DS10-DS11 DS10-DS11 DS10-DS11 DS10-DS11
Card 2
Card 2
Card 2
Card 2
Card 2
Card 2
Card 2
column 6
column 7
column 8
column 9
column 10
column 11
column 12
DS12-DS13 DS12-DS13 DS12-DS13 DS12-DS13 DS12-DS13 DS12-DS13 DS12-DS13
Card 3
Card 3
Card 3
Card 3
Card 3
Card 3
Card 3
column 12
column 11
column 10
column 9
column 8
column 7
column 6
DS16-DS17 DS16-DS17 DS16-DS17 DS16-DS17 DS16-DS17 DS16-DS17 DS16-DS17
Card 4
Card 4
Card 4
Card 4
Card 4
Card 4
Card 4
column 12
column 11
column 10
column 9
column 8
column 7
column 6
DS22-DS23 DS22-DS23 DS22-DS23 DS22-DS23 DS22-DS23 DS22-DS23 DS22-DS23
Card 5
Card 5
Card 5
Card 5
Card 5
Card 5
Card 5
column 12
column 11
column 10
column 9
column 8
column 7
column 6
DS24-DS25 DS24-DS25 DS24-DS25 DS24-DS25 DS24-DS25 DS24-DS25 DS24-DS25
Card 6
Card 6
Card 6
Card 6
Card 6
Card 6
Card 6
column 6
column 7
column 8
column 9
column 10
column 11
column 12
DS28-DS29 DS28-DS29 DS28-DS29 DS28-DS29 DS28-DS29 DS28-DS29 DS28-DS29
Note:
MSD — Most significant digit
LSD — Least significant digit
6-12
14
Card 1
column 5
DS8-DS9
Card 2
column 5
DS12-DS13
Card 3
column 5
DS16-DS17
Card 4
column 5
DS20-DS21
Card 5
column 5
DS24-DS25
Card 6
column 5
DS28-DS29
Principles of Operation
U18
6.5.2 Front panel keys
KEYCLK
HCT32
U18
U9
DISPCLK
6522A
HCT32
VIA
CB1
CB2
PB1
PB0
FPCLK
U23
FPDATA
KEY
BLANK
DISPDATA
U22
HCT125
HCT00
BLANK
U23
To
Display
Board
KEYDATA
U28
HCT244
Figure 6-9
Display interface simplified schematic
The front panel keys are SPST normally-open pushbutton
switches. They are connected in a 6-column by 7-row array.
Each column is connected to one of the column drive outputs
of decoder U27 (74HCT154) through a diode. The diodes
isolate the columns from one another in case more than one
key on the same row is pressed. As the display is multiplexed, each key column is pulled low in its turn. The other
columns float.
Each row is connected to Vcc through a pull-up resistor and
to one of the inputs of parallel-to-serial converter U28
(74HCT165). The load input of U28 is connected to the
BLANK signal, so that each time new data is sent to the display, another column of the key array gets latched into U28.
6.5.3 Display interface
6.5.1 Display data
The digital board sends display data (DISPDATA) to the display board serially. Nine bytes are required: eight bytes of
segment data and one byte to select the column.
All displays are arranged as common cathode. The segment
anodes are driven by source drivers U11-U18 (UCN5895A)
connected in a serial data chain. Each source driver has eight
outputs and an output disable. (While new data is being sent
to the display drivers, the BLANK line is set high to disable
the outputs.) Display data is first shifted into serial-toparallel converter U20 (74HCT164) and then to the chain of
segment source drivers.
Four parallel outputs of U20 are decoded by the 4-to-16
decoder U27 (74HCT154). The outputs of this decoder drive
the display cathodes through sink drivers U1-U5
(UDN2597A).
The display interface circuitry of the digital board generates
clock signals and communicates serial data for the front
panel display and keyboard. The shift register of U9 (6522A
VIA) controls the display and reads the key array. Pin CB1 is
the clock signal (FPCLK) and pin CB2 is the data signal
(FPDATA).
Signal FPCLK is generated for both serial output (display)
and serial input (keyboard) operations. This single bi-directional port is converted to two uni-directional ports by two
OR gates of U18 (74HCT32), two tri-state drivers of U23
(74HCT125), and a NAND gate of U22 (74HCT00) used as
an inverter.
When the low true KEY signal (generated on VIA pin PB1)
is asserted, DISPCLK is held high, KEYCLK follows
FPCLK, the KEYDATA driver (U23) is enabled, and the
DISPDATA driver (U23) is disabled.
When the low true KEY signal is negated, the KEYCLK signal is held high and the DISPCLK signal follows FPCLK.
Also, the KEYDATA driver is disabled while the DISPDATA
driver is enabled. The remaining signal that goes to the display board, BLANK, is generated by VIA output pin PB0.
6-13
Principles of Operation
6.5.4 Refresh display/read keyboard
7. Read the VIA shift register again to get the byte of KEYDATA.
8. Negate the low true KEY line.
9. Configure the VIA shift register for output.
The refresh display/ read keyboard sequence is as follows:
NOTE
During power-on hardware initialization,
the U9 shift register (6522A VIA) is configured for Output and the low true KEY
signal is negated.
6.6
Light pen interface
The light pen interface circuitry resides on the digital board.
A simplified schematic is shown in Figure 6-10.
The light pen is a self-contained unit requiring only a 5-volt
supply. It returns two TTL-compatible signals:
1. Set the BLANK line high.
2. Send nine bytes of DISPDATA out the VIA shift register
to drive the next column in the multiplex sequence.
3. Set the BLANK line low.
4. Configure the VIA shift register for input.
5. Assert the low true KEY line.
6. Read the VIA shift register to cause the KEYDATA to be
shifted into the VIA.
• SENSEPULSE — A low-going pulse of about 15µsec
width that occurs as the light intensity at the end of the
pen rises above a preset threshold.
• LPSWITCH — A debounced switch signal that is low
while the light pen pushbutton is depressed.
+5V
U10
U19
65C 21
HCT244
PIA
PA2
U21
SLAVE
LPSENSE
+5V
'38
U24
LPRESET
MASTER/SLAVE
CONNECTORS
HCT74
D
U23
Q
HCT125
CLR
U19
U9
HCT244
6522A
+5V
VIA
PB7
LPSENSE
U21
CA2
LPRESET
'38
CA1
U23
LPSWITCH
LPSWITCH
HCT125
IRQ
TO
68B09
IRQ
Figure 6-10
Light pen interface simplified schematic
6-14
SENSEPULSE
LIGHT
PEN
CONNECTOR
Principles of Operation
The rising edge of SENSEPULSE clocks a high into flip-flop
U24 (74HCT74). This converts the signal into a level that
can be read by the microprocessor through the PB7 input of
U9 (6522A VIA) as signal LPSENSE (low true).
If the low true SLAVE signal from U10 (65C21 PIA) is high
(i.e., the unit is either a stand-alone or master), the microprocessor reads its own U24 flip-flop. The output of U24 also
gets driven onto the LPSENSE line of the master/slave connectors. If SLAVE is asserted, the microprocessor reads the
LPSENSE signal from the master/slave connectors.
The microprocessor can clear flip-flop U24 by setting the
LPRESET output of U9 high. This signal also gets driven
onto the master/slave connectors by open-collector driver
U21. This method permits the master and all slaves in a master/slave system to read and clear the U24 flip-flop in the
master unit. Thus, one light pen can serve for all units, while
each unit controls its own display for the scan routine.
The switch signal (low true LPSWITCH) goes to the CA1
interrupt input of the VIA, which is programmed to generate
an IRQ interrupt on the falling edge of LPSWITCH. The
interrupt service routine stops the normal display refresh
multiplexing and takes over control of the display.
The routine then scans the display one column at a time,
clearing flip-flop U24 before scanning each column. After
the display is scanned, the processor examines the
LPSENSE signal to determine if the light pen “sees” one of
the LEDs that is currently being scanned.
If a master scans its display and gets no response from the
light pen, it instructs the slaves in turn to scan their displays.
Each slave monitors the U24 flip-flop of the master to check
whether or not the light pen “sees” any of the LEDs that are
lit on its own display.
6.7
Master/slave circuitry
The master/slave interface is a closed loop of serial communication and bused control signals. Its control circuitry
resides on the digital board. See Figure 6-11 for a simplified
schematic.
Each mainframe has a Master/Slave In connector and a Master/Slave Out connector. Serial data is sent from the
TXDATA pin of the output connector to the RXDATA pin of
the input connector on the next mainframe in the loop. All
other interface signals (M/S TRIGGER, ALLREADY,
LPRESET, and LPSENSE) are common to input and output
connectors. The light pen signals LPRESET and LPSENSE
are described in paragraph 6.6.
6.7.1 Serial communication
Serial data communication is managed by U11 (68B50
ACIA) and automatic retransmit logic: a U22 NAND gate
used as an inverter, U5 AND gates, and U18 OR gate.
The RTS (low true) output of U11 controls the automatic
retransmission of serial data. Stand-alone and master units
assert RTS to gate the TXDATA output of U11 through a U5
AND gate and via U18 onto the TXDATA pin of the master/
slave interface. Relay K1 is energized (as shown) whenever
power is applied to the Model 707A.
Slave units negate RTS except when responding to a request
by the master for setup or status information. A negated RTS
signal blocks the TXDATA signal at its corresponding U5
AND gate. Incoming serial data to the RXDATA input of
U11 is also routed through a U5 gate, the U18 OR gate, and
onto the master/slave TXDATA pin to effect the automatic
retransmission.
6-15
Principles of Operation
RXDATA
U4
E
ALLREADY
HCT74
U11
D
68B50
M/S TRIGGER
Q
ACIA
Q
TXCLK
RXCLK
LPRESET
LIGHT
PEN
INTERFACE
894.89 kHz
MASTER/SLAVE
IN
LPSENSE
U19
U5
HCT244
RXDATA
HCT08
U22
U18
RTS
U5
HCT00
K1 (Energized)
+5V
TXDATA
HCT08
HCT244
HCT32
AA
A
IRQ
TO
68B09
FIRQ
+5V
U10
65C21
TXDATA
U21
IMREADY
PIA
PA1
PA0
PA2
ALLREADY
U19
M/S TRIGGER
38
ALLREADY
LPRESET
+5V
SLAVE
MASTER/SLAVE
OUT
LPSENSE
HCT244
U21
CA2
CA1
M/S TRIGGER
TRIGGER
O.C.
U19
38
U20
HCT157
IRQ
TO
68B09
IRQ
Figure 6-11
Master/slave interface simplified schematic
6-16
HCT244
1Y
S
U19
1I1
1I0
HCT244
EXTERNAL
TRIGGER
BNC
Principles of Operation
6.7.2 Control signals
Bused control signals are managed by U10 (65C21 PIA).
Bused outputs are driven by U21 (7438 open-collector
NAND) and are buffered for input with U19 receivers.
The SLAVE (low true) signal selects the external trigger
source:
• In slave units, the SLAVE signal is asserted. This causes
multiplexer U20 to select the M/S TRIGGER (low true)
signal for the trigger interrupt. Slaves are disabled from
driving the M/S TRIGGER signal by the U21 NAND.
• In master or stand-alone units, SLAVE is negated and
multiplexer U20 selects the External Trigger Input BNC
for the trigger interrupt. This also enables the unit to
drive the M/S TRIGGER signal via the U21 NAND.
The ALLREADY signal is wire-ORed so that it is negated
whenever any unit in the master/slave loop has negated its
IMREADY (low true) signal when receiving and processing
data. When a slave unit is powered down, relay K1 provides
a path to digital ground, simulating a negated IMREADY
signal. This provides positive indication to other units on the
master/slave loop that one of the units is not running.
(Power-up software waits until all units have asserted their
IMREADY signal.)
Assertion of M/S TRIGGER when the ALLREADY signal is
false causes the slave units to reset to a known state. (Asserting M/S TRIGGER with ALLREADY true triggers the
slaves.)
6.8
Digital I/O
The digital input and digital output ports are two separate
interfaces, even though they are on the same DB25 connector. A simplified schematic of the circuitry is shown in Figure
6-12.
Digital inputs are managed by U13 (74HCT373 transparent
latch), which is decoded as a port on the microprocessor bus
by PAL U2. U13 latches in the states of lines IN (0:7) whenever the INLATCH (low true) signal is asserted or the microprocessor reads the digital input port.
Digital outputs are managed by port B of U10. The OUTPULSE (low true) signal on pin CB2 is asserted for about
one E clock cycle (600nsec) after the microprocessor has
written to the port B output lines OUT (0:7).
6.9
IEEE-488 bus interface
The Model 707A has an IEEE-488 standard interface that
allows the instrument to be programmed from a system controller. Commands can be sent over the bus to the instrument
and data can be requested from the instrument.
The IEEE-488 interface is made up of U14, U15, and U16.
U14 is a 9914A GPIA (general purpose interface adapter),
while U15 and U16 are interface bus drivers.
The GPIA simplifies microprocessor interfacing to the
IEEE-488 bus because many control sequences take place
automatically. For example, when the microprocessor writes
to the GPIA data output register, the handshake sequence is
performed automatically. Without the GPIA chip, complex
microprocessor routines would be required.
On the microprocessor side of the GPIA, data transmission
is handled much like any other data bus transaction. Microprocessor data access is performed through the D0-D7 lines,
while A0-A2 (the three least significant address lines) select
among the 14 internal registers (seven read, seven write) of
the GPIA. Chip selection is performed by the SELECT 9914
line.
The output of the GPIA is in standard IEEE-488 format. All
of these lines are active low with approximately zero volts
representing a logic one:
• Eight data lines (D1-D8).
• Three handshake lines (DAV, NRFD, NDAC).
• Five management lines (ATN, REN, IFC, SRQ, EOI).
The two IEEE-488 bus drivers, U15 and U16, bring the drive
capability of the interface up to the requirements of the
IEEE-488 standard, which includes provisions for up to 15
devices on the bus at once. The outputs of the bus drivers are
connected to J25, a standard IEEE-488 connector.
To cause the microprocessor to read the input lines, the
INLATCH signal is also routed to the CB1 input of U10
(65C21 PIA), which is programmed to generate an interrupt
on a falling edge.
6-17
Principles of Operation
U10
74HCT374
U29 HCT244
OUT 0
PB0
OUT 1
PB1
OUT 2
PB2
OUT 3
PB3
OUT 4
PB4
OUT 5
PB5
OUT 6
PB6
OUT 7
PB7
OUTPULSE
CB2
U30
CB1
HCT244
IRQ
TO
68B09
IRQ
U13
HCT373
IN 0
D0
IN 1
D1
IN 2
D2
IN 3
D3
IN 4
D4
IN 5
D5
IN 6
D6
IN 7
D7
U30
U5
E
HCT08
U2
HCT244
16P8A
OE
Figure 6-12
Digital I/O interface simplified schematic
6-18
O1
INLATCH
Principles of Operation
6.10 Power supply
The major component of the power section is a single output
switching power supply. Its 6.2V output is distributed to the
backplane board for the relay coils of the switching cards,
and to the voltage regulator board. The 5V output of the voltage regulator board is supplied to all logic circuitry, including that on the switching cards, and to the front panel display
board.
6-19
7
Maintenance
7.1
Introduction
This section contains information necessary to maintain and
troubleshoot the Model 707A Switching Matrix. Handling
and cleaning procedures are also included.
7.9
Mainframe troubleshooting: Outlines troubleshooting procedures for the Model 707A.
7.10 Using an extender card: Explains usage of an
extender card to access switching card circuitry.
7.11 Cleaning: Gives the procedure for cleaning the backplane board and the fan filter.
WARNING
The servicing procedures in this section
are intended only for qualified electronics service personnel. Do not attempt to
perform these procedures unless you are
qualified to do so. Some of the procedures may expose you to potentially
lethal voltages (>30V RMS) that could
result in personal injury or death if normal safety precautions are not observed.
The section is outlined as follows:
7.2
7.3
7.4
7.5
7.6
7.7
7.8
Line Voltage Sensing: Provides a description of setting the instrument operating voltage.
Fuse Replacement: Gives the procedure for replacing
the line fuse located on the rear panel.
Fixed Rack Installation: Lists the installation
instructions for a fixed rack mount kit for a Model
707A.
Disassembly: Covers the procedure for disassembling
the instrument, including circuit board removal.
Backplane Jumpers: Covers removal and installation
of the backplane jumpers.
Battery Replacement: Outlines the procedure for
replacing the lithium battery.
Static-sensitive Devices: Covers precautions necessary when handling static-sensitive parts within the
instrument.
7.2
Line voltage sensing
The Model 707A operates from a line voltage in the range of
100 to 240V, at a frequency of 50 or 60Hz. Line voltage and
frequency are automatically sensed, therefore there are no
switches to set. Check to see that the line power in your area
is compatible.
Perform the following steps to connect the power supply to
the line power and turn it on:
1. Before plugging in the power cord, make sure the front
panel power switch is in the off (0) position.
2. Connect the female end of the supplied power cord to
the AC receptacle on the rear panel.
WARNING
The power cord supplied with the Model
707A contains a separate ground use
with grounded outlets. When proper
connections are made, instrument chassis is connected to power line ground
through the ground wire in the power
cord. Failure to use a grounded outlet
may result is personal injury or death
due to electric shock.
7-1
Maintenance
7.3
Fuse replacement
7.4
The line fuse, located on the rear panel, protects the power
line input of the instrument. Use the following procedure to
replace the fuse, if necessary.
Fixed rack installation
Table 7-2 lists the necessary hardware for a fixed mounting
of a Model 707A in a 19” wide rack (24 to 30” deep). Verify
that all parts are available before beginning the installation
procedure.
WARNING
Disconnect the instrument from the
power line and other equipment before
replacing the fuse.
1. With the power off, place the end of a flat-bladed screwdriver into the slot in the rear panel fuse holder. Press in
gently and rotate the fuse holder approximately onequarter turn counterclockwise. Release pressure on the
holder and allow the internal spring to push the carrier
and fuse out of the holder.
2. Separate the fuse from the carrier by carefully pulling
the two apart.
3. Using an ohmmeter, check the fuse for continuity. A
good fuse will show low resistance, while a blown fuse
will read high (essentially infinite) resistance.
4. If the old fuse is defective, replace it with the type recommended in Table 7-1.
CAUTION
Do not use a fuse with a higher rating
than specified, or instrument damage
may occur. If the instrument repeatedly
blows fuses, locate and correct the cause
of the problem before resuming operation of the unit.
5. Install the new fuse, located in the fuse carrier, by
reversing the above procedure.
Table 7-1
Line fuse values
Line Voltage
Range
Fuse Rating
100 to 240 VAC 5A, 250V, slow blow, 3AG
7-2
Keithley
Part No.
FU-64
Table 7-2
Fixed rack parts
Item
Description
Keithley
Part No.
Qty.
A
B
C
Chassis Support (1eft)
Chassis Support (right)
Nut, #10-32 Captive
707-321
707-322
FA-148
1
1
4
D
E
F
G
Bracket Kit consisting of:
Rear Support Bracket
Spacer Bar
Nut Bar
Screw, #10-32 × 1/2” Phil.
Binder Hd.
BR-31
—
—
—
—
1
2
2
4
12
Rack preparation
1. Select a position in the rack. In most cases, the weight
of the Model 707A dictates a position in the lower half
of the rack. The Model 707A will take up 14” of vertical
space.
NOTE
The mainframe must be mounted at a
height that is an increment of 1-3/4” from
the top or bottom of the rack. Attempting
to mount the mainframe at a nonincremental height will lead to difficulties
with hole alignment.
2. Referring to Figure 7-1, install two captive nuts (item C)
on each front rack flange at holes 11-3/8” and 13-1/8”
from the top of the selected space.
3. Loosely attach a nut bar (item F) to each rear rack flange
with two binder head screws (item G). See Figure 7-2.
Mount the nut bars with the outer holes at the same level
as the captive nuts. Note that the hole pattern on the nut
bar is not symmetrical.
Maintenance
Chassis support preparation
Front Rack
Flange
113/8"
131/8"
Captive Nuts
(Item C)
14"
4. Place a rear support bracket (item D) on the left chassis
support (item A) and temporarily install the two pieces
in the rack by sliding them apart until their flanged ends
fit as shown in Figure 7-3. Note which holes will be used
to attach the two pieces together.
5. Use a spacer bar, nut bar, and two binder head screws
(items E, F, and G) to loosely attach each rear support
bracket to a chassis support. Figure 7-4 shows the left
side support.
13/4"
Chassis support mounting
6. Reinstall the chassis support assemblies in the rack and
secure them to the captive nuts with binder head screws.
Also tighten the binder screws at the rear rack flange.
7. Tighten the screws attaching the two pieces of the chassis support assemblies.
Figure 7-1
Captive nut installation
Mainframe installation
8. Lift the Model 707A mainframe onto the chassis supports and slide it into the rack.
9. The mainframe can be secured to the front rack flanges
with user-supplied captive nuts and binder head screws
(four each).
NOTE
AA
AA
Binder Screws
(Item G)
AA
AA
1 3/4"
Nut Bar
(Item F)
The chassis supports hold the Model 707A
in place while you are mounting the mainframe to the front rack flanges. Once the
Model 707A is secured, there may be a
gap between the mainframe and the chassis supports.
Rear Rack
Flange
Figure 7-2
Nut bar on flange
7-3
Maintenance
Chassis Support-Left
(Item A)
Rear Support
Bracket
(Item D)
Binder Screw
(Item G)
AA
Nut Bar
(Item F)
Captive Nut
(Item C)
Front Rack
Flange
Rear Rack
Flange
Figure 7-3
Chassis support sizing
Nut Bar
(Item F)
Rear Support
Bracket
(Item D)
Chassis Support-Left
(Item A)
Space Bar
(Item E)
AA
AA
AA
AA
Figure 7-4
Chassis support assembly
7-4
Binder
Screws
(Item G)
Maintenance
7.5
Disassembly
If it is necessary to troubleshoot the instrument or replace a
component, use the following disassembly procedure. In addition to the figures, use the assembly drawings at the end of
this section to assist you as you disassemble and re-assemble
the Model 707A.
•
•
•
•
•
•
Rear panel assembly — 707A-030
Rear panel wiring — 707A-031
Front panel assembly — 707A-040
Chassis assembly/wiring — 707A-050
Final chassis wiring assembly — 707A-051
Final inspection — 707A-080
WARNING
Before disassembly, disconnect the line
cord, ensure no voltage is applied from
user circuits, and remove all plug-in
cards from the instrument.
1. With the Model 707A on a bench, remove the front
panel as follows:
A. Place a thin book or other support under the unit to
slightly raise the bottom edge of the front panel off
the bench surface.
B. Remove the four pan-head screws that secure the
right and left handle mounting brackets to the side
covers. Figure 7-5 shows a view of the right side.
C. Remove the three flat-head screws securing each
side of the front panel to the right and left side
covers.
D. Gently pull the front panel away from the mainframe. It may be necessary to loosen the two panhead screws holding the backplane support bracket.
E. Swing the front panel to the left and rest it on its
edge as shown in Figure 7-6.
Figure 7-5
Right side view of disassembly
7-5
Maintenance
Figure 7-6
Front view of disassembly
2. As shown in the assembly drawings, remove the left side
cover:
A. Remove the ten pan-head screws securing the left
side cover, including the one previously loosened in
step 1D.
B. Pull the side cover off its support tabs.
3. Remove the display board as follows:
A. Unplug the following connections:
P32 — Digital board connection to light pen connector on front panel.
P34 — Digital board ribbon cable connection to display board.
P36 — Display board connection to voltage regulator board.
B. Disconnect the plug between the power switch on
the front panel and the terminal strip in front of the
digital board.
C. Remove the four screws securing the display board
shield and display board to the front panel.
4. Remove the backplane board as follows:
CAUTION
Avoid touching the board surface. Contamination can result in degraded
matrix card performance. If contamination occurs, clean the board as described
in paragraph 7.11.
A. Remove the backplane support bracket shown in
Figure 7-6.
7-6
B. Unplug the following connections:
P33 — Digital board ribbon cable connection to
backplane board.
P33 — Backplane board connection to power
supply.
C. Remove the grounding wires from the grounding
stud on the rear panel.
D. Lift the backplane board by its edges off the backplane support tabs.
5. Referring to the assembly drawings, remove the digital
board as follows:
A. On the Model 707A rear panel, pull off the Relay
Test connector (P24). Also unscrew the two black
standoffs from the IEEE-488 connector (J25).
B. On the digital board, disconnect the following plugs
(if not previously removed):
P29 — Connector to External Trigger and Matrix
Ready jacks.
P30 — Ribbon cable connector to Digital I/O port.
P31 — Connector to power supply.
P32 — Connector to light pen connector on front
panel.
P33 — Ribbon cable connector to backplane board.
P34 — Ribbon cable connector to display board.
C. Remove the five screws securing the digital board to
the mainframe and lift out the board.
6. Reverse the above procedure to re-assemble the
instrument.
Maintenance
7.6
Backplane jumpers
The Model 707A backplane has jumpered connections
between slots 3 and 4 for the following general purpose
signals:
CAUTION
Do not touch the surface of the backplane to prevent possible contamination
from body oil and dirt, which could
degrade insulation resistance.
• HI and LO of analog bus #1 (e.g., rows C-F of Model
7072).
• HI, LO, and Guard of analog bus #2 (e.g., rows A-H of
Model 7071).
4. The backplane jumpers are called out in Figure 7-7. Remove them by snipping with diagonal cutters.
These jumpers can be removed to selectively isolate the signals of slots 1-3 from slots 4-6. If all jumpers are removed,
there will be two 3-slot general purpose analog backplanes in
one mainframe. An example system configuration using this
isolation method is described in Section 3.
If it is necessary to clean the connector side of the backplane
or re-insert backplane jumpers (Keithley part number J-15)
continue with these steps:
The following steps outline the procedure for removing
backplane jumpers. Also refer to Figures 7-5 through 7-7.
WARNING
Turn off mainframe power and disconnect the line cord. Ensure no voltage is
applied from user circuits, then remove
all cards.
1. Set the mainframe on a bench. (Slightly raise the bottom
edge of the front panel off the bench surface by placing
a thin book under the mainframe.) Remove the eight
pan-head screws holding the handles to the unit.
2. Remove the six flat-head screws attaching the front
panel.
3. Grasping the right side of the front panel, swing it to the
left approximately 45˚ and rest it on its edge.
5. Remove the two pan-head screws attaching the backplane support bracket, and remove the bracket.
6. Handle the board by the edges only. Do not touch any
board surfaces. When servicing, wear clean, white cotton gloves.
7. If making solder repairs on the board, use a flux that is
rosin RMA based. Remove the flux from these areas
when the repair is complete. Use methanol and clean
cotton swabs to remove the flux. Take care not to spread
the flux to other areas of the board.
8. Once the flux has been removed, swab only the repaired
area with methanol, and then blow-dry the board with
dry nitrogen gas.
9. After cleaning, the board should be placed in a 50˚C low
humidity environment for several hours.
10. Reassemble the unit taking care to align the backplane
with its supports before attaching the front panel and
handles.
7-7
Maintenance
Slot 3
Slot 4
J104
J103
Figure 7-7
Backplane jumpers
7-8
Row C HI
Row C LO
W1
W2
Row D HI
Row D LO
W3
W4
Row E HI
Row E LO
W5
W6
Row F HI
Row F LO
W7
W8
W9
W10
W11
Row A HI
Row A LO
Row A Guard
W12
W13
W14
Row B HI
Row B LO
Row B Guard
W15
W16
W17
Row C HI
Row C LO
Row C Guard
W18
W19
W20
Row D HI
Row D LO
Row D Guard
W21
W22
W23
Row E HI
Row E LO
Row E Guard
W24
W25
W26
Row F HI
Row F LO
Row F Guard
W27
W28
W29
Row G HI
Row G LO
Row G Guard
W30
W31
W32
Row H HI
Row H LO
Row H Guard
Maintenance
7.7
Battery replacement
When line power to the Model 707A is turned off, the lithium
battery on the digital board provides backup power to the
memory in which setups and parameters are stored. The battery has enough capacity to maintain data for one year of
continuous power off, or two years if the Model 707A is
powered on for 12 hours every day. The battery by itself has
a shelf life of eight years. Although the Model 707A will operate without a battery, it will not retain any setups or parameters when turned off and will power up in random
conditions.
The battery may be replaced with any CR2450 lithium coin
cell. It can also be ordered from Keithley Instruments (part
number BA-44), as discussed in Section 8 of this manual.
5. Reinstall the left side panel and handle.
6. Reinstall the power line cord and turn on the Model
707A. It will power up in random conditions, such as
make/break and break/make on the same rows.
7.8
Static-sensitive devices
CMOS devices are designed to operate at high impedance
levels for lower power consumption. As a result, any static
charge that builds up on your person or clothing may be sufficient to destroy these devices if they are not handled properly. Use the precautions below when handling staticsensitive devices:
NOTE
Replacement of the lithium battery is normally a safe procedure as long as these safety precautions are followed.
WARNING
The precautions below must be followed
to avoid possible personal injury.
1. Wear safety glasses or goggles when working with lithium batteries.
2. Do not short the battery terminals together.
3. Do not incinerate or otherwise expose to excessive heat
(>60˚C).
4. Keep lithium batteries away from all liquids.
5. Do not recharge lithium batteries.
6. Observe proper polarity when inserting battery into
holder.
Replace the battery as follows:
1. Turn off the power and remove the line cord from the
Model 707A.
2. Remove the left handle and side panel. (See paragraph
7.5.)
3. The lithium battery is on the digital board. Pry the battery out of its holder using a non-metallic tool.
WARNING
Do not use a metal tool to pry out the
battery as you could short its terminals.
4. Install the new battery, taking care to observe proper
polarity as stamped on the battery holder.
Since the many CMOS devices installed in
the Model 707A are not denoted in this
manual, all ICs and transistors should be
handled as static-sensitive devices.
1. Transport such devices only in containers designed to
prevent static build-up. Typically, these parts will be
received in anti-static containers of plastic or foam.
Always leave the devices in question in their original
containers until ready for installation.
2. Remove the devices from their protective containers
only at a properly grounded work station. Also ground
yourself with a suitable wrist strap.
3. Handle the devices only by the body; do not touch the
pins or terminals.
4. Any printed circuit board into which the device is to be
inserted must also be properly grounded to the bench or
table.
5. Use only anti-static type de-soldering tools.
6. Use only soldering irons with properly grounded tips.
7. Once the device is installed on the PC board, it is usually
adequately protected, and normal handling can resume.
7.9
Mainframe troubleshooting
This troubleshooting information is intended for qualified
personnel having a basic understanding of digital and analog
circuitry. The individual should also be experienced at using
common test equipment, as well as ordinary troubleshooting
procedures. The information has been written to assist in isolating a defective circuit or circuit section. Isolation of the
specific component is left to the technician.
7-9
Maintenance
Note that component layout drawings are located at the end
of Section 8. Also, refer to Section 6 for an overview of operating principles.
These three tests can also be performed from the front panel
through a menu selection (SELF TEST) or over the
IEEE-488 bus with the command J0 (Perform Self-test).
7.9.1 Recommended test equipment
7.9.3 Power supply checks
Success in troubleshooting equipment like the Model 707A
depends not only on the skill of the technician, but also on
the use of accurate, reliable test equipment. Table 7-3 lists
the minimum recommended equipment for troubleshooting.
Other equipment, such as logic analyzers, could also be
helpful.
Power supply voltages should be checked first to make sure
they are within the required limits. If the various operating
voltages are not within the limits, troubleshooting the remaining circuitry can be quite difficult.
Table 7-3
Recommended troubleshooting equipment
Description
Application
DMM (Keithley 2000)
Measure dc voltage.
Dual-trace, triggered sweep Check clock and logic
oscilloscope, dc to 50MHz pulses.
Table 7-4 outlines the voltages that should be checked. In
addition to the usual checks with a voltmeter, it is a good idea
to check the supplies with an oscilloscope to make sure that
no noise or ringing is present.
7.9.4 Digital board checks
Tables 7-5 through 7-8 list the procedures to check circuitry
on the digital board, including the microcomputer, relay control circuitry, display interface, and digital I/O port.
Procedures for testing the light pen and master/slave interface options are listed in Tables 7-9 and 7-10.
7.9.2 Power-up self-test
As described in Section 4, the Model 707A performs a series
of tests on power-up. Individual tests in this series that can be
used for troubleshooting a Model 707A include:
• ROM test - A checksum test of ROM. Test failure is indicated by a ROM FAIL error message.
The waveforms described in the troubleshooting tables are
present with power-up default conditions (idle state), unless
otherwise indicated. To view some of the waveforms, it will
be helpful to run a program loop. Refer to the programs of
Figure 7-10 when directed by the procedure.
• RAM test - A read/write test of battery backed-up
CMOS RAM. Test failure is indicated by a RAM FAIL
error message.
NOTE
If the ROM (U7) must be replaced for any
reason, restore the Model 707A to factory
default conditions with a menu selection
(FACTORY INIT) or the device-dependent command R0.
• Display test - A visual test of the front panel displays.
• Check for all LEDs and indicators being lit.
Table 7-4
Power supply checks
Step
Item/component
Signal
Comments
1
2
PS1
Voltage Regulator PCB
6.2VDC ±2% (0.12V)
5VDC ±1% (0.05V)
Measure relay coil voltage at power supply.
Measure logic voltage and front panel display voltage at
voltage regulator board TP103 referenced to TP101.
7-10
Maintenance
Table 7-5
Microcomputer checks
Step
Item/component
Signal
Comments
The following digital board signals are referenced to
digital common.
1
2
3
4
5
U6 pin 37
U6 pin 34
U9 pin 23
U6 pins 8-23
U6 pins 24-31
MPU Reset
E clock
SELECT VIA
Address bus (A0-A15)
Data bus (D0-D7)
Stays low (110-260msec on power-up), then goes high.
1.79MHz square wave for peripheral chips.
Low going pulses (1kHz).
Check for stuck bit.
Check for stuck bit.
Signal
Comments
Table 7-6
Relay control checks
Step
Item/component
The following digital board signals are referenced to digital
common.
1
2
U9 pin 23
U28 pin 5
SELECT VIA
CLRADDR
3
U28 pin 3
NEXTADDR
4
5
6
7
U28 pin 6
U12 pin 11
U12 pin 16
U12 pins 2,5,6,9,12,15
IDDATA
SELECT CARDSEL
STROBE
CARD(1-6)
8
9
U24 pin 1
U28 pin 7
SELECT RELAYDATA
CLK
10
U28 pin 18
RELAYDATA
See Figure 7-9 for waveforms of steps 8 through 10.
Low going pulses (1kHz).
High logic pulse at start of each matrix card ID byte transfer
sequence on power-up.
Low logic pulse before each byte transfer from matrix card
on power-up.
Matrix card ID logic pulse train on power-up.
Pair of low going pulse trains when program #1 is running.
High logic pulse to strobe relay drivers on matrix card.
Low logic pulse selects matrix card for data transfer
sequence.
Low going pulse when program #1 is running.
Eight low-going pulses (1.79MHz square wave) after each
SELECT RELAYDATA pulse.
Logic pulses to load relay drivers on matrix card.
7-11
Maintenance
Table 7-7
Display interface checks
Step
Item/component
Signal
Comments
The following digital board signals are referenced to digital
common.
1
2
U9 pin 23
U9 pin 18
SELECT VIA
FPCLK
3
U18 pin 6
DISPCLK
4
U18 pin 3
KEYCLK
5
6
U23 pin 6
U23 pin 2
DISPDATA
KEYDATA
See Figure 7-10 for waveforms of steps 2 through 6.
Low going pulses (1kHz).
Base frequency of 895kHz with ten sets of pulses every
lmsec.
Base frequency of 895kHz with nine sets of pulses every linsec.
Base frequency of 895kHz with one set of pulses every linsec.
See Figure 7-10.
See Figure 7-10.
Signal
Comments
Table 7-8
Digital I/O checks
Step
Item/component
The following digital board signals are referenced to digital
common.
1
2
3
4
5
7-12
U10 pin 23
U10 pins 10-17
U10 pin 19
U13 pin 1
U13 pins 3, 4, 7, 8, 13,
14, 17, 18
SELECT PIA
OUT(0-7)
OUTPULSE
SELECT DIG INPUT
IN(0-7)
Low going pulses (1kHz).
Logic low when programmed low.
Low going pulses (600nsec) when program #2 is running.
Low going pulses (5kHz) when digital input is displayed.
Logic high when port disconnected.
Maintenance
Table 7-9
Light pen checks
Step
Item/component
Signal
Comments
The following digital board signals are referenced to digital
common.
1
2
U9 pin 23
U23 pin 12
SELECT VIA
SENSEPULSE
3
4
U23 pin 9
U9 pin 17
LPSWITCH
LPSENSE
5
U9 pin 39
LPRESET
Low going pulses (1kHz).
Low going pulse (15µsec) when light pen is pointed at lit
LED.
Low logic level when light pen button is pressed.
High going pulse when light pen button is pressed and pen is
pointed at an LED.
Multiple high going pulses when light pen button is pressed.
Signal
Comments
Table 7-10
Master/slave checks
Step
Item/component
The following digital board signals are referenced to digital
common.
1
2
3
4
5
6
U11 pins 3,4
U11 pin 9
U11 pins 2,6
U11 pin 7
U10 pin 23
U10 pin 39
RXCLK, TXCLK
SELECT ACIA
RXDATA, TXDATA
FIRQ
SELECT PIA
M/S TRIGGER
When troubleshooting a single unit, loop a cable from
Master/Slave Out to Master/Slave In of the same unit,
then program unit as master.
895kHz square wave.
Low going pulses with manual triggers.
Low going pulse pair with manual trigger.
Low going pulse with manual trigger.
Low going pulses (1kHz).
High going pulses when program #3 is running. (Triggering
stops when Relay Step equals 100.)
7-13
Maintenance
PROGRAM #1
PROGRAM #2
PROGRAM #3
START
START
START
CLOSE A1
SET DIGITAL
OUTPUT TO ZERO
SELECT TRIGGER
ON GET
OPEN A1
DELAY 0.1 SEC
ENABLE TRIGGERS
TRIGGER ON GET
Figure 7-8
Troubleshooting programs
7.9.5 Display board checks
To troubleshoot the display board, it is helpful to disassemble it from the front panel, then reconnect the power cable
and ribbon cable with the display board on a bench.
A troubleshooting procedure is outlined in Table 7-11.
Table 7-11
Display board checks
Step
Item/component
Signal
Comments
The following display board signals are referenced to digital
common.
1
2
U13 pin 12
U3 pin 17
Source driver
Sink driver
3
U11 pins 6-12;
U12 pins 5-12
U1 pins 4-7, 14-16;
U2 pins 4-7, 14-17
Source drivers
Sink drivers
U27 pins 1-6
U28 pins 3-5, 11-14
Button columns
Button rows
4
5
6
7-14
When troubleshooting the LED array, check for these
signals when the LED is lit (e.g., crosspoint A1).
Card row A - Logic high for 9msec.
Card column 1 - Logic low.
Segment displays:
Low going pulses (1kHz) with all segments lit.
Low going pulses (1kHz).
Front panel buttons:
Logic high with a low going 1msec pulse.
Logic high with a low going 1msec pulse when button
pressed.
Maintenance
SELECT RELAYDATA
CLK
RELAYDATA
D7
D6
D5
D4
D3
D2
D1
D0
Figure 7-9
Relay control waveforms
Repeated every 1msec
FP CLK
895 kHz
Repeated every 1msec
DIS P CLK
895 kHz
Repeated every 1msec
KE YCLK
895 kHz
DIS P DATA
1ms ec
KE YDATA
1ms ec
Figure 7-10
Display interface waveforms
7-15
Maintenance
7.10 Using an extender card
To access circuitry on the plug-in relay cards of the Model
707A, use a Model 7070 Universal Adapter Card. The Model
7070 must be configured as an extender card by placing the
configuration jumper in the EXTEND position. See the
Model 7070 Instruction Manual for complete details on
using the card.
7.11 Cleaning
7.11.1 Backplane
Since card rows are extended on the three analog backplanes
of the Model 707A (as explained in Section 3), a contaminated backplane will degrade card isolation specifications. If an
isolation problem exists, the backplane should be cleaned
only after the isolation of each card has been tested according to the respective card manuals.
The following procedure is primarily intended to clean high
impedance PC boards, such as the Model 707A backplane,
but it can be used to clean all PC boards. To remove the backplane, refer to paragraph 7.5.
1. Handle the board by the edges only. Do not touch any
board surfaces. When servicing, wear clean, white cotton gloves.
2. If making solder repairs on the board, use a flux that is
rosin RMA based. Remove the flux from these areas
when the repair is complete. Use methanol and clean
cotton swabs to remove the flux. Take care not to spread
the flux to other areas of the board.
3. Once the flux has been removed, swab only the repaired
area with the methanol, then blow-dry the board with
dry nitrogen gas.
7-16
4. After cleaning, the board should be placed in a 50˚C low
humidity environment for several hours.
7.11.2 Fan filter
The fan filter, which is located on the rear panel, keeps dirt
from being drawn into the instrument by the internal cooling
fan. The filter opening should be kept free of obstructions to
ensure proper instrument cooling.
The filter should be checked periodically for dirt build-up,
and cleaned or replaced, as necessary. Use the following procedure to clean or replace the filter.
1.
2.
3.
4.
Disconnect the line cord from the power line receptacle.
Grasp the filter holder, and pull it free of the rear panel.
Remove the filter element from the holder.
Soak the filter in a solution of warm water and mild
detergent until clean. Rinse thoroughly in clean water,
and allow the filter to dry completely before installation.
If a new filter assembly is required, one may be obtained
by ordering Keithley part number FL-6.
NOTE
Do not operate the instrument with the filter removed to avoid dirt build-up within
the instrument.
5. If necessary, clean the fan guard with a damp cloth.
6. Install the filter element in the holder and snap the
holder back onto the fan guard. The two tabs on the
holder should be oriented at the right and left sides.
8
Replaceable Parts
8.1
Introduction
This section contains replacement parts information and
component layout drawings for the Model 707A.
8.2
Parts lists
The parts lists for the Model 707A are shown in Tables 8-1
through 8-6.
8.3
Ordering information
To place an order or to obtain information concerning replacement parts, contact your Keithley representative or the
factory (see front of manual for addresses). When ordering
parts, be sure to include the following information:
• Instrument model number (Model 707A)
• Instrument serial number
• Part description
• Component designation (if applicable)
• Keithley part number
8.4
Factory service
If the instrument is to be returned to Keithley Instruments for
repair, perform the following:
1. Call the Repair Department at 1-800-552-1115 for a Return Material Authorization (RMA) number.
2. Complete the service form at the back of this manual,
and include it with the instrument.
3. Carefully pack the instrument in the original packing
carton.
4. Write ATTENTION REPAIR DEPARTMENT and the
RMA number on the shipping label.
8.5
Component layouts and schematic
The component layouts are provided in the following pages:
Digital board: 707-100
Display board: 707-110
Backplane board: 707A-120
Voltage regulator board: 707A-160
A schematic of the Backplane board (707A-126) is also
included.
To facilitate repairs, complete circuit boards are available.
Contact the Repair Department for pricing and availability.
8-1
Replaceable Parts
Table 8-1
Digital board assembly
Circuit designation
Description
Keithley part no.
BT1
BATTERY, LITHIUM-MANGANESE CELL 3V
BATTERY HOLDER
CAP, .01UF, 20%, 50V, CERAMIC
CAP, 15PF, 10%, 1000V, CERAMIC
CAP, 270PF, 20%, 100V, CERAMIC/FERRITE
CAP, 3.3UF, 10%, 16V, ALUM ELEC
CAP, 10UF, -20+100%, 25V, ALUM ELEC
DIODE, BRIDGE, VM18
CONN, 8 PIN CIRCULAR DIN
CONN, 6 PIN OPEN END HEADER
CONN, RIGHT ANGLE, 24 PIN
CONN, MALE, 3 PIN
CONN, MALE HEADER 26-PIN
CONN, MALE, 2 PIN
CONN, MALE, 4 PIN
CONN, HEADER STRAIGHT SOLDER PIN
RELAY, MINIATURE (DPDT)
RES, 10, 10%, 2W, COMPOSITION
INTEGRATED CIRCUIT
INTEGRATED CIRCUIT
IC, 8 BIT MICROPROCESSING UNIT, MC68B09
IC, VERSATILE INTERFACE ADAPTER, 6522A
IC, PERIPHERAL INTERFACE ADAPTER, 63B21
CRYSTAL, 7.15909MHZ
BA-44
BH-34
C-365-.01
C-64-15P
C-386-270P
C-321-3.3
C-314-10
RF-52
CS-589
CS-587-6
CS-507
CS-288-3
CS-322-26
CS-288-2
CS-288-4
CS-368-20
RL-98
R-3-10
IC-573
IC-574
LSI-65
LSI-45
LSI-61
CR-24-4
C6
C31, C32
C33-90
C91
C92
CR1-17
J22, J23
J24
J25
J29
J30, J33
J31
J32
J34
K1
R39
U1
U2
U6
U9
U10
Y1
8-2
Replaceable Parts
Table 8-2
Display board assembly
Circuit designation
Description
Keithley part no.
PUSHBUTTON, BLACK
CAP, 270PF, 20%, 100V, CERAMIC/FERRITE
DIGITAL DISPLAY (DOUBLE DIGIT)
DIG DISP (5X7 DOT MATRIX DISP), 2057-AE
PILOT LIGHT, RED, LED
228-317-8B
C-386-270P
DD-39
DD-44
PL-71
PILOT LIGHT, YELLOW, LED
LED MOUNTS
LED MOUNTS
CABLE ASSEMBLY, 20 CONDUCTOR
SWITCH, MOMENTARY
IC,8-BIT SERIAL-INPUT, UNC5895A
PL-72
MK-22-1
MK-22-2
CA-27-8
SW-435
IC-537
Circuit designation
Description
Keithley part no.
J19
J101, J102, J103, J104, J105, J106
J113, J114, J115, J116, J117, J118
J107, J108, J109, J110, J111, J112
CABLE ASSEMBLY
CONNECTOR, CARD EDGE
CONNECTOR, CARD EDGE
CONNECTOR, CARD EDGE
FASTENER
JUMPER
CA-27-7
CS-579-1
CS-591-1
CS-591-2
FA-230-4B
J-15
Circuit designation
Description
Keithley part no.
C101
C102, C103
CR101, CR102
CAP, .1UF, 20%, 50V, CERAMIC
CAP, 22UF, 20%, 20V TANTALUM
DIODE, SILICON, IN4006 (D0-41)
THERMAL TUBE
HEAT SINK
CONN, MALE, 2 PIN
CONN, STRAIGHT POST HEADER, 3-PIN
INTEGRATED CIRCUIT
C-365-.1
C-179-22
RF-38
HS-49-2A
HS-56
CS-288-2
CS-533-3
IC-1226
C16,C17
DS1, DS2, DS3, DS4, DS5, DS6, DS7
DS8-31
DS32, DS33, DS34, DS36, DS37,
DS38, DS39, DS40
DS35
FOR PL-71
FOR PL-72
P34
S1-41
U13, U14, U15, U16
Table 8-3
Backplane assembly
W1-W32
Table 8-4
Voltage regulator assembly
HS101
J30, J37
J36
U101
8-3
Replaceable Parts
Table 8-5
Chassis assembly
Description
Keithley part no.
BRACKET POWER SUPPLY
CABLE CLAMP
CABLE CLAMP, NYLON
CHASSIS
CONNECTOR, HARDWARE KIT
CONNECTOR, PLUG TERMINAL
REAR PANEL
SINGLE OUTPUT SWITCHING POWER SUPPLY
707A-301B
CC-37
CC-34
707A-306A
CS-713
CS-588-6
707A-304
PS-65A
Table 8-6
Miscellaneous
8-4
Description
Keithley part no.
BRACKET RACK MOUNT LEFT
BRACKET RACK MOUNT RIGHT
CHASSIS SUPPORT, LEFT
CHASSIS SUPPORT, RIGHT
DC FAN
HANDLE
LINE CORD
707A-308A
707A-307A
707-322
707-321
FN-33-3
HH-30-4
CO-7
M2
M3
M4
A
Card Configuration Worksheet
A-1
Card Configuration Worksheet
Slot: ___________________________________
Mainframe:
Model: _______________________
Stand-alone _________
Master _____________ Slave 1 _____________ Slave 2 _____________ Slave 3 _____________ Slave 4 ___________
System size:
_______________________ rows __________ columns ___________ IEEE address ___________
FROM
(Instrument connection or DUT pin)
External Card
Connection
TO
(Instrument connection or DUT pin)
Row A
B
C
D
E
F
G
H
Column 1
2
3
4
5
6
7
8
9
10
11
12
Expansion:
___ Backplane bus (rows through ribbon cable)
___ Point to point writing (rows/cols.)
___ BNC coax cable (rows/cols.)
Notes:
A-2
___ SMB coax jumpers (rows)
___ Mass terminated cable (rows/cols.)
___ Triax cable (rows/cols.)
B
IEEE-488 Bus Overview
B.1
Introduction
The IEEE-488 bus is a communication system between two
or more electronic devices. A device can be either an instrument or a computer. When a computer is used on the bus, it
serves as a supervisor of the communication exchange
between all the devices and is known as the controller.
Supervision by the controller consists of determining which
device will talk and which device will listen. As a talker, a
device will output information. As a listener, a device will
receive information. To simplify the task of keeping track of
the devices, a unique address number is assigned to each.
On the bus, only one device can talk at a time and is
addressed to talk by the controller. The device that is talking
is known as the active talker. The devices that need to listen
to the talker are addressed to listen by the controller. Each
listener is then referred to as an active listener. Devices that
do not need to listen are instructed to unlisten. The reason for
the unlisten instruction is to optimize the speed of bus information transfer since the task of listening takes up bus time.
Through the use of control lines, a handshake sequence takes
place in the transfer process of information from a talker to a
listener. This handshake sequence helps ensure the credibility of the information transfer. The basic handshake
sequence between an active controller (talker) and a listener
is:
1. The listener indicates that it is ready to listen.
2. The talker places the byte of data on the bus and indicates that the data is available to the listener.
3. The listener, aware that the data is available, accepts the
data and then indicates that the data has been accepted.
4. The talker, aware that the data has been accepted, stops
sending data and indicates that data is not being sent.
5. The listener, aware that there is no data on the bus, indicates that it is ready for the next byte of data.
B.2
Bus description
The IEEE-488 bus, which is also referred to as the GPIB
(General Purpose Interface Bus), was designed as a parallel
transfer medium to optimize data transfer without using an
excessive number of bus lines. In keeping with this goal, the
bus has only eight data lines that are used for data and with
most commands. Five bus management lines and three handshake lines round out the complement of bus signal lines.
A typical setup for controlled operation is shown in Figure
B-1. Generally, a system will contain one controller and a
number of other instruments to which the commands are
given. Device operation is categorized into three operators:
controller, talker, and listener. The controller controls the
instruments on the bus. The talker sends data while a listener
receives data. Depending on the type of instrument, any particular device can be a talker only, a listener only, or both a
talker and listener.
There are two categories of controllers: system controller
and basic controller. Both are able to control other instruments, but only the system controller has the absolute
authority in the system. In a system with more than one controller, only one controller may be active at any given time.
Certain protocol is used to pass control from one controller
to another.
The IEEE-488 bus is limited to 15 devices, including the
controller. Thus, any number of talkers and listeners up to
that limit may be present on the bus at one time. Although
several devices may be commanded to listen simultaneously,
B-1
IEEE-488 Bus Overview
the bus can have only one active talker, or communications
would be scrambled.
A device is placed in the talk or listen state by sending an
appropriate talk or listen command. These talk and listen
commands are derived from an instrument’s primary
address. The primary address may have any value between 0
and 31, and is generally set by rear panel DIP switches or
programmed in from the front panel of the instrument. The
actual listen address value sent out over the bus is obtained
by ORing the primary address with $20. For example, if the
primary address is $16, the actual listen address is $36 ($36
= $16 + $20). In a similar manner, the talk address is
obtained by ORing the primary address with $40. With the
present example, the talk address derived from a primary
address of $16 would be $56 ($56 = $16 + $40).
The IEEE-488 standards also include another addressing
mode called secondary addressing. Secondary addresses lie
in the range of $60-$7F. Note, however, that many devices,
including the Model 707A, do not use secondary addressing.
TO OTHER DEVICES
DEVICE 1
ABLE TO
TALK, LISTEN
AND CONTROL
(COMPUTER)
DATA BUS
DEVICE 2
ABLE TO
TALK AND
LISTEN
7001
DEVICE 3
ONLY ABLE
TO LISTEN
(PRINTER)
GENERAL
INTERFACE
MANAGEMENT
DEVICE 4
ONLY ABLE
TO TALK
Once a device is addressed to talk or listen, the appropriate
bus transactions take place. For example, if the instrument is
addressed to talk, it places its data string on the bus one byte
at a time. The controller reads the information, and the
appropriate software can be used to direct the information to
the desired location.
D 101 ... 8 DATA
(8 LINES)
DAV
NRFD
NDAC
IFC
ATN
SRQ
REN
EOI
Figure B-1
IEEE-488 bus configuration
B-2
DATA BYTE
TRANSFER
CONTROL
HANDSHAKE
BUS
MANAGEMENT
IEEE-488 Bus Overview
B.3
Bus lines
The signal lines on the IEEE-488 bus are grouped into three
different categories: data lines, management lines, and handshake lines. The data lines handle bus data and commands,
while the management and handshake lines ensure that
proper data transfer and operation take place. Each bus line
is active low, with approximately zero volts representing a
logic 1 (true). The following paragraphs describe the operation of these lines.
B.3.1 Data lines
The IEEE-488 bus uses eight data lines that transfer data one
byte at a time. DIO1 (Data Input/Output) through DIO8
(Data Input/Output) are the eight bi-directional data lines
used to transmit both data and multiline commands. The data
lines operate with low true logic.
B.3.2 Bus management lines
The five bus management lines help to ensure proper interface control and management. These lines are used to send
the uniline commands.
• ATN (Attention) — The state of the ATN line determines how information on the data bus is to be interpreted.
• DAV (DATA VALID) — The source controls the state
of the DAV line to indicate to any listening devices
whether or not data bus information is valid.
• NRFD (Not Ready For Data) — The acceptor controls
the state of NRFD. It is used to signal to the transmitting
device to hold off the byte transfer sequence until the
accepting device is ready.
• NDAC (Not Data Accepted) — NDAC is also controlled by the accepting device. The state of NDAC tells
the source whether or not the device has accepted the
data byte.
The complete handshake sequence for one data byte is
shown in Figure B-2. Once data is placed on the data lines,
the source checks to see that NRFD is high, indicating that
all active devices are ready. At the same time, NDAC should
be low from the previous byte transfer. If these conditions are
not met, the source must wait until NDAC and NRFD have
the correct status. If the source is a controller, NRFD and
NDAC must be stable for at least 100ns after ATN is set true.
Because of the possibility of a bus hang up, many controllers
have time-out routines that display messages in case the
transfer sequence stops for any reason.
DATA
SOURCE
DAV
SOURCE
VALID
• IFC (Interface Clear) — The IFC line controls clearing
of instruments from the bus.
• REN (Remote Enable) —The REN line is used to place
the instrument on the bus in the remote mode.
• EOI (End or Identify) — The EOI line is used to mark
the end of a multi-byte data transfer sequence.
• SRQ (Service Request) — The SRQ line is used by
devices when they require service from the controller.
B.3.3 Handshake lines
The bus handshake lines operate in an interlocked sequence.
This method ensures reliable data transmission regardless of
the transfer rate. Generally, data transfer will occur at a rate
determined by the slowest active device on the bus.
One of the three handshake lines is controlled by the source
(the talker sending information), while the remaining two
lines are controlled by accepting devices (the listener(s)
receiving the information). The three handshake lines are:
ALL READY
ACCEPTOR
NRFD
ALL ACCEPTED
NDAC
ACCEPTOR
Figure B-2
IEEE-488 handshake sequence
Once all NDAC and NRFD are properly set, the source sets
DAV low, indicating to accepting devices that the byte on the
data lines is now valid. NRFD will then go low, and NDAC
will go high once all devices have accepted the data. Each
device will release NDAC at its own rate, but NDAC will not
be released to go high until all devices have accepted the data
byte.
The previous sequence is used to transfer both data, talk, and
listen addresses, as well as multiline commands. The state of
the ATN line determines whether the data bus contains data,
addresses, or commands as described in the following paragraphs.
B-3
IEEE-488 Bus Overview
B.4
Bus commands
The instrument may be given a number of special bus commands through the IEEE-488 interface. The following paragraphs briefly describe the purpose of the bus commands that
are grouped into the following categories.
by the controller or other devices depending on the direction
of data transfer. The following is a description of each command. Each command is sent by setting the corresponding
bus line true.
• REN (Remote Enable) — REN is sent to set up instruments on the bus for remote operation. When REN is
true, devices will be removed from the local mode.
Depending on device configuration, all front panel controls except the LOCAL button (if the device is so
equipped) may be locked out when REN is true. Generally, REN should be sent before attempting to program
instruments over the bus.
• Uniline commands — Sent by setting the associated bus
lines true. For example, to assert REN (Remote
Enable), the REN line would be set low (true).
• Multiline commands — General bus commands that are
sent over the data lines with the ATN line true (low).
• Common commands — Commands that are common to
all devices on the bus and are sent with ATN high
(false).
• EOI (End or Identify) — EOI is used to positively identify the last byte in a multi-byte transfer sequence, thus
allowing data words of various lengths to be transmitted
easily.
• SCPI commands — Commands that are particular to
each device on the bus and are sent with ATN (false).
These bus commands and their general purpose are summarized in Table B-1.
• IFC (Interface Clear) — IFC is used to clear the interface and return all devices to the talker and listener idle
states.
B.4.1 Uniline commands
• ATN (Attention) — The controller sends ATN while
transmitting addresses or multiline commands.
ATN, IFC, and REN are asserted only by the controller. SRQ
is asserted by an external device. EOI may be asserted either
• SRQ (Service Request) — SRQ is asserted by a device
when it requires service from a controller.
Table B-1
IEEE-488 bus command summary
Command
State of
ATN
Comments
line
Uniline
REN (Remote Enable)
EOI
IFC (Interface Clear)
ATN (Attention)
SRQ
X
X
X
Low
X
Set up devices for remote operation.
Marks end of transmission.
Clears interface.
Defines data bus contents.
Controlled by external device.
Multiline
Universal
LLO (Local Lockout)
DCL (Device Clear)
SPE (Serial Enable)
SPD (Serial Poll Disable)
Low
Low
Low
Low
Locks out local operation.
Returns device to default conditions.
Enables serial polling.
Disables serial polling.
Addressed
SDC (Selective Device Clear) Low
Low
GTL (Go To Local)
Command
type
Unaddressed UNL (Unlisten)
UNT (Untalk)
B-4
Low
Low
Returns unit to default conditions.
Returns device to local.
Removes all listeners from the bus.
Removes any talkers from the bus.
IEEE-488 Bus Overview
B.4.2 Universal multiline commands
Universal commands are those multiline commands that
require no addressing. All devices equipped to implement
such commands will do so simultaneously when the commands are transmitted. As with all multiline commands,
these commands are transmitted with ATN true.
• LLO (Local Lockout) — LLO is sent to the instrument
to lock out the LOCAL key and all their front panel controls.
• DCL (Device Clear) — DCL is used to return instruments to some default state. Instruments usually return
to their power-up conditions.
• SPE (Serial Poll Enable) — SPE is the first step in the
serial polling sequence that is used to determine which
device has requested service.
• SPD (Serial Poll Disable) — SPD is used by the controller to remove all devices on the bus from the serial
poll mode and is generally the last command in the
serial polling sequence.
B.4.3 Addressed multiline commands
Addressed commands are multiline commands that must be
preceded by the device listen address before that instrument
will respond to the command in question. Note that only the
addressed device will respond to these commands. Both the
commands and the address preceding it are sent with ATN
true.
• SDC (Selective Device Clear) — The SDC command
performs essentially the same function as the DCL
command except that only the addressed device
responds. Generally, instruments return to their powerup default conditions when responding to the SDC
command.
• GTL (Go To Local) — The GTL command is used to
remove instruments from the remote mode. With some
instruments, GTL also unlocks front panel controls if
they were previously locked out with the LLO command.
• GET (Group Execute Trigger) — The GET command is
used to trigger devices to perform a specific action that
depends on device configuration (for example, take a
reading). Although GET is an addressed command,
many devices respond to GET without addressing.
B.4.4 Address commands
• LAG (Listen Address Group) — These listen commands are derived from an instrument’s primary
address and are used to address devices to listen. The
actual command byte is obtained by ORing the primary
address with $20.
• TAG (Talk Address Group) — The talk commands are
derived from the primary address by ORing the address
with $40. Talk commands are used to address devices to
talk.
• SCG (Secondary Command Group) — Commands in
this group provide additional addressing capabilities.
Many devices (including the Model 707A) do not use
these commands.
B.4.5 Unaddress commands
The two unaddress commands are used by the controller to
remove any talkers or listeners from the bus. ATN is true
when these commands are asserted.
• UNL (Unlisten) — Listeners are placed in the listener
idle state by the UNL command.
• UNT (Untalk) — Any previously commanded talkers
will be placed in the talker idle state by the UNT command.
B.4.6 Command codes
Command codes for the various commands that use the data
lines are summarized in Figure B-3. Hexadecimal and decimal values for the various commands are listed in Table B-2.
Table B-2
Hexadecimal and decimal command codes
Command
Hex value
Decimal value
GTL
SDC
GET
LLO
DCL
SPE
SPD
LAG
TAG
SCG
UNL
UNT
01
04
08
11
14
18
19
20-3F
40-5F
60-7F
3F
5F
1
4
8
17
20
24
25
32-63
64-95
96-127
63
95
Addressed commands include two primary command groups
and a secondary address group. ATN is true when these commands are asserted. The commands include:
B-5
Figure B-3
Command codes
B-6
PRIMARY
COMMAND
GROUP
(PCG)
TALK
ADDRESS
GROUP
(TAG)
UNIVERSAL
COMMAND
GROUP
(UCG)
ADDRESSED
COMMAND
GROUP
(ACG)
LISTEN
ADDRESS
GROUP
(LAG)
15
?
15
/
SI
15
1
o
n
30
UNT
∩

14
N
O
30
UNL
>
14
.
RS
US
SO
14
0
1
1
1
1
1
1
:
}
m
29
]
13
M
29
=
13
-
GS
CR
13
1
0
1
1
{
l
28
\
12
L
28
<
12
,
FS
FF
12
0
0
1
1
z
k
27
[
11
K
27
;
11
+
ESC
VT
11
1
1
0
1
y
j
26
Z
10
J
26
:
10
•
SUB
LF
10
0
1
0
i
25
Y
9
I
25
9
9
)
1
x
h
24
X
8
H
24
8
8
(
SPE
EM
9
1
0
0
SPD
CAN
GET
TCT*
BS
HT
8
0
0
0
1
23
7
23
7
7
‘
1
v
w
f
g
22
V
W
6
F
G
22
6
6
&
ETB
BEL
7
1
1
1
SYN
ACK
6
0
1
1
0
e
21
5
E
21
5
5
0
t
u
d
20
T
U
4
D
20
4
4
$
%
DCL
5
1
0
1
0
PPU*
DC4
NAK
SDC
PPC*
EOT
ENQ
4
0
0
1
0
r
s
c
19
S
3
C
19
3
3
#
DC3
ETX
3
1
1
0
0
q
b
18
R
2
B
18
2
2
“
DC2
STX
2
0
1
0
0
17
1
SECONDARY
COMMAND
GROUP
(SDC)
DEL
≅
p
a
16
P
Q
0
A
7 (A)
@
6 (B)
17
6 (A)
X
1
1
1
16
5 (B)
X
1
1
0
1
LLO
1
DC1
DLE
0
5 (A)
X
1
0
1
0
GTL
!
1
1
0
0
0
SP
NUL
SOH
0
0
0
0
0
Primary
Address
4 (B)
X
1
0
0
Primary
Address
4 (A)
3 (A)
X
0
1
1
Primary
Address
3(B)
2 (B)
1 (B)
X
0
1
0
Primary
Address
2 (A)
0 (A)
Column→
Row ↓
D0
↓
D1
↓
1 (A)
X
0
0
1
D2
↓
0 (B)
Command
D3
↓
X
0
0
0
Command
*PPC (PARALLEL POLL CONFIGURE) PPU (PARALLEL POLL UNCONFIGURE),
and TCT (TAKE CONTROL) not implemented by Model 708.
Note: D0 = DIO1 ... D7 = DIO8; X = Don’t Care.
Bits
D7
D6
D5
D4
7 (B)
IEEE-488 Bus Overview
IEEE-488 Bus Overview
B.4.7 Typical command sequences
B.4.8 IEEE command groups
For the various multiline commands, a specific bus sequence
must take place to properly send the command. In particular,
the correct listen address must be sent to the instrument
before it will respond to addressed commands. Table B-3
lists a typical bus sequence for sending the addressed multiline commands. In this instance, the SDC command is being
sent to the instrument. UNL is generally sent as part of the
sequence to ensure that no other active listeners are present.
Note that ATN is true for both the listen command and the
SDC command byte itself.
Command groups supported by the Model 707A are listed in
Table B-5.
Table B-5
IEEE command groups
HANDSHAKE COMMAND GROUP
NDAC = NOT DATA ACCEPTED
NRFD = NOT READY FOR DATA
DAV = DATA VALID
UNIVERSAL COMMAND GROUP
Table B-3
Typical addressed command sequence
ATN = ATTENTION
DCL = DEVICE CLEAR
IFC = INTERFACE CLEAR
REN = REMOTE ENABLE
SPD = SERIAL POLL DISABLE
SPE = SERIAL POLL ENABLE
Data bus
Step Command
ATN state
ASCII
1
2
3
4
UNL
LAG*
SDC
?
Set low
0
Stays low
EOT
Stays low
Returns high
Hex
Decimal
3F
30
04
63
48
4
ADDRESS COMMAND GROUP
LISTEN
*Assumes primary address = 16.
TALK
Table B-4 gives a typical common command sequence. In
this instance, ATN is true while the instrument is being
addressed, but it is set high while sending the common command string.
Typical common command sequence
Data bus
ATN state
ASCII Hex Decimal
1
2
3
4
5
6
UNL
LAG*
Data
Data
Data
Data
Set low
Stays low
Set high
Stays high
Stays high
Stays high
?
0
*
R
S
T
ADDRESSED COMMAND GROUP
ACG = ADDRESSED COMMAND GROUP
GTL = GO TO LOCAL
SDC = SELECTIVE DEVICE CLEAR
Table B-4
Step Command
LAG = LISTEN ADDRESS GROUP
MLA = MY LISTEN ADDRESS
UNL = UNLISTEN
TAG = TALK ADDRESS GROUP
MTA = MY TALK ADDRESS
UNT = UNTALK
OTA = OTHER TALK ADDRESS
3F
30
2A
52
53
54
63
48
42
82
83
84
STATUS COMMAND GROUP
RQS = REQUEST SERVICE
SRQ = SERIAL POLL REQUEST
STB = STATUS BYTE
EOI = END
*Assumes primary address = 16.
B-7
IEEE-488 Bus Overview
B.5
Interface function codes
The interface function codes, which are part of the IEEE-488
standards, define an instrument’s ability to support various
interface functions and should not be confused with programming commands found elsewhere in this manual. The
interface function codes for the Model 707A are listed in
Table B-6.
Table B-6
Model 707A interface function codes
Code
Interface function
SH1
AH1
T5
Source Handshake capability
Acceptor Handshake capability
Talker (basic talker, talk-only, serial poll, unaddressed to talk on LAG)
Listener (basic listener, unaddressed to listen on
TAG)
Service Request capability
Remote/Local capability
No Parallel Poll capability
Device Clear capability
Device Trigger capability
No Controller capability
Open collector bus drivers
No Extended Talker capability
No Extended Listener capability
L4
SR1
RL1
PP0
DC1
DT1
C0
E1
TE0
LE0
The codes define Model 707A capabilities as follows:
• SH (Source Handshake Function) — SH1 defines the
ability of the instrument to initiate the transfer of message/data over the data bus.
B-8
• AH (Acceptor Handshake Function) — AH1 defines
the ability of the instrument to guarantee proper reception of message/data transmitted over the data bus.
• T (Talker Function) — The ability of the instrument to
send data over the bus to other devices is provided by
the T function. Instrument talker capabilities (T5) exist
only after the instrument has been addressed to talk.
• L (Listener Function) — The ability of the instrument
to receive device-dependent data over the bus from
other devices is provided by the L function. Listener
capabilities (L4) of the instrument exist only after it has
been addressed to listen.
• SR (Service Request Function) — SR1 defines the
ability of the instrument to request service from the
controller.
• RL (Remote/Local Function) — RL1 defines the ability
of the instrument to be placed in the remote or local
modes.
• PP (Parallel Poll Function) — The instrument does not
have parallel polling capabilities (PP0).
• DC (Device Clear Function) — DC1 defines the ability
of the instrument to be cleared (initialized).
• DT (Device Trigger Function) — DTI defines the ability of the Model 708 to have readings triggered.
• C (Controller Function) — The instrument does not
have controller capabilities (C0).
• E (Bus Driver Type) — The instrument has open-collector bus drivers (E1).
• TE (Extended Talker Function) — The instrument does
not have extended talker capabilities (TE0).
• LE (Extended Listener Function) — The instrument
does not have extended listener capabilities (LE0).
Index
A
A — External trigger 5-16
Address commands B-5
Address decoding 6-2
Addressed multiline commands B-5
Alphanumeric display 4-4
B
B — Matrix ready 5-17
Backplane 7-16
Backplane jumpers 7-7
Basic switching operation 3-22
Battery replacement 7-9
Bus cable connections 5-3
Bus commands B-4
Bus description B-1
Bus lines B-3
Bus management lines B-3
Digital board checks 7-10
Digital I/O 4-14, 6-17
Disassembly 7-5
Display board checks 7-14
Display circuitry 6-10
Display data 6-13
Display interface 6-13
Display messages 4-5
Displays and messages 4-4
Documenting system configuration 3-20
E
E — Edit pointer 5-19
Expanding matrix size 3-10
External trigger 4-14
External trigger input 4-25
F
C
C — Close crosspoint 5-18
Card configuration worksheet A-1
Card connections 3-8
Card installation 2-1
Card labels 4-18
Cleaning 7-16
Command codes B-5
Component layouts and schematics 8-1
Concurrent front panel and bus
operation 5-10
Control signals 6-17
Copying crosspoint display 4-11
Crosspoint display LEDs 4-6
F — Enable/disable triggers 5-19
Factory defaults 4-18
Factory service 8-1
Fan filter 7-16
Features 1-1
Fixed rack installation 7-2
Front panel aspects of IEEE-488
operation 5-8
Front panel error messages 5-8
Front panel familiarization 3-1
Front panel keys 6-13
Front panel triggering 4-21
Fuse replacement 7-2
G
D
D — Display 5-18
Data lines B-3
DCL (device clear) 5-11
Device-dependent command (DDC)
programming 5-12
G — Data format 5-20
General bus command programming 5-10
General information 1-1
GET (group executive trigger) 5-11
Getting started 3-1
GTL (go to local) 5-11
H
H — Hit key 5-25
Handshake lines B-3
I
I — Insert blank setup 5-26
IEEE command groups B-7
IEEE-488 bus address 4-17
IEEE-488 bus interface 6-17
IEEE-488 bus overview B-1
IEEE-488 bus triggering 4-25
IEEE-488 programming 5-1
IEEE-488 quick start 5-1
IEEE-488 status indicators 4-6
IFC (interface clear) 5-11
Inserting and deleting stored setups 4-12
Inspection for damage 1-2
Installing and removing cards 2-1
Interface function codes 5-5, B-8
Introduction 1-1, 3-1, 4-1, 5-1, 6-1, 7-1,
8-1, B-1
J
J — Self-test 5-26
K
K — EOI and hold-off 5-26
L
L — Download setups 5-27
Light pen 4-8
Light pen interface 6-14
Line power connections 4-2
Line voltage selection 4-2
Line voltage sensing 7-1
LLO (local lockout) 5-11
Local key 5-10
i-1
M
Q
T
M — SRQ and serial poll byte 5-28
Mainframe troubleshooting 7-9
Maintenance 7-1
Make/break and break/make LEDs 4-8
Make/break and break/make rows 4-19
Manual addenda 1-1
Master/slave circuitry 6-15
Master/slave power-up 4-4
Matrix ready 4-15
Matrix ready output 4-25
Memory 6-4
Menu operations 4-12
Microcomputer 6-1
Modifying a relay setup 3-22
Modifying crosspoint display 4-10
Multiple unit expansion 3-16
Q — Delete setup 5-31
QuickBASIC programming 5-7
T — Trigger 5-33
Timing considerations 5-43
Trigger overrun conditions 4-21
Trigger sources 4-20
Triggering 4-20
Typical command sequences B-7
R
R — Restore defaults 5-32
Rear panel familiarization 3-6
Recommended test equipment 7-10
Refresh display/read keyboard 6-14
Relay command combinations 5-42
Relay control circuitry 6-4
Relay (hardware) settling times 4-18
REN (remote enable) 5-10
Repacking for shipment 1-2
Replaceable parts 8-1
Reset circuit 6-1
Resetting 4-25
N
N — Open crosspoint 5-30
O
O — Digital output 5-30
Operation 4-1
Optional accessories 1-2
Ordering information 8-1
Overall function description 6-1
Overview 5-10, 5-12
P
P — Clear crosspoints 5-31
Parts lists 8-1
Power supply 6-19
Power supply checks 7-10
Power switch 4-2
Power-up 3-22
Power-up configuration 4-3
Power-up procedure 4-2
Power-up self-test 7-10
Power-up self-test and messages 4-2
Primary address programming 5-6
Principles of operation 6-1
Programmed settling time 4-19
i-2
U
U — Status 5-34
Unaddress commands B-5
Uniline commands B-4
Universal multiline commands B-5
Unpacking and inspection 1-2
Using an extender card 7-16
V
S
S — Programmed settling time 5-32
Safety symbols and terms 1-2
SDC (selective device clear) 5-11
Selecting crosspoint display 4-10
Selecting make/break and break/make
rows 3-22
Selecting switching parameters 4-19
Self-test 4-18
Serial communication 6-15
Setup data paths 4-1
Shipment contents 1-2
Single unit expansion 3-10
SPE, SPD (serial polling) 5-11
Specifications 1-2
Stand-alone and master/slave 4-16
Static-sensitive devices 7-9
Status indicators 5-9
Storing setup and sending to relays 3-23
Switching card interface 6-6
Switching card logic 6-6
System expansion issues 3-20
V — Make/break 5-39
W
W — Break/make 5-39
Warranty information 1-1
X
X — Execute 5-40
Y
Y — Terminator 5-41
Z
Z — Copy setup 5-41
Service Form
Model No.
Serial No.
Date
Name and Telephone No.
Company
List all control settings, describe problem and check boxes that apply to problem.
❏
Intermittent
❏
Analog output follows display
❏
Particular range or function bad; specify
❏
❏
IEEE failure
Front panel operational
❏
❏
Obvious problem on power-up
All ranges or functions are bad
❏
❏
Batteries and fuses are OK
Checked all cables
Display or output (check one)
❏
❏
❏
Drifts
Unstable
Overload
❏
❏
Unable to zero
Will not read applied input
❏
❏
Calibration only
❏
CertiÞcate of calibration required
Data required
(attach any additional sheets as necessary)
Show a block diagram of your measurement system including all instruments connected (whether power is turned on or not).
Also, describe signal source.
Where is the measurement being performed? (factory, controlled laboratory, out-of-doors, etc.)
What power line voltage is used?
Relative humidity?
Ambient temperature?
Other?
Any additional information. (If special modiÞcations have been made by the user, please describe.)
Be sure to include your name and phone number on this service form.
¡F
Keithley Instruments, Inc.
28775 Aurora Road
Cleveland, Ohio 44139
Printed in the U.S.A.
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