Anritsu 681XXC synthesized signal generator GPIB Programming Manual

SERIES
681XXC
SYNTHESIZED SIGNAL GENERATOR
GPIB PROGRAMMING MANUAL
490 JARVIS DRIVE
MORGAN HILL, CA 95037-2809
P/N: 10370-10334
REVISION: A
PRINTED: JANUARY 1999
COPYRIGHT 1999 ANRITSU CO.
WARRANTY
The Anritsu product(s) listed on the title page is (are) warranted against defects in materials and
workmanship for one year from the date of shipment.
Anritsu’s obligation covers repairing or replacing products which prove to be defective during the
warranty period. Buyers shall prepay transportation charges for equipment returned to Anritsu for
warranty repairs. Obligation is limited to the original purchaser. Anritsu is not liable for consequential damages.
LIMITATION OF WARRANTY
The foregoing warranty does not apply to Anritsu connectors that have failed due to normal wear.
Also, the warranty does not apply to defects resulting from improper or inadequate maintenance by
the Buyer, unauthorized modification or misuse, or operation outside of the environmental specifications of the product. No other warranty is expressed or implied, and the remedies provided
herein are the Buyer’s sole and exclusive remedies.
TRADEMARK ACKNOWLEDGEMENTS
Adobe Acrobat is a registered trademark of Adobe Systems Incorporated.
NOTICE
Anritsu Company has prepared this manual for use by Anritsu Company personnel and customers
as a guide for the proper installation, operation and maintenance of Anritsu Company equipment
and computer programs. The drawings, specifications, and information contained herein are the
property of Anritsu Company, and any unauthorized use or disclosure of these drawings, specifications, and information is prohibited; they shall not be reproduced, copied, or used in whole or in
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MANUAL CHANGES
0$18$/
7LWOH Series 681XXC Synthesized Signal Generator GPIB Programming Manual
3DUW1XPEHU 10370-10334
5HY/WU'DWH A / January 1999
&+$1*(3$&.(7
3DUW1XPEHU 10900-00283
,16758&7,216
1. Make the manual changes listed below. The changes are listed in numerical order by page number.
Effectivity is all 681XXC models with Firmware Version 1.01 and above.
2. The replacement pages provided are for technical changes to the manual. The black bar or bars in the
replacement page margins shows the area in which the changes were made.
&+$1*(0D\
3DJH
Replace with enclosed pages 2-5 and 2-6, Changed: May 1999.
3DJHVDQG
Replace with enclosed pages 2-41 thru 2-46, Changed: May 1999.
3DJH$
Insert enclosed page 2-41A/2-42A, Changed: May 1999.
3DJH$
Replace with enclosed pages A-11 and A-12, Changed: May 1999.
(&1 MI001082
681XXC PM
C-1
Table of Contents
Chapter 1 - General GPIB Information
1-1
SCOPE OF MANUAL . . . . . . . . . . . . . . . . . 1-3
Electronic Manual . . . . . . . . . . . . . . . . . . 1-3
1-2
INTRODUCTION . . . . . . . . . . . . . . . . . . . 1-3
1-3
IEEE-488 INTERFACE BUS DESCRIPTION . . . 1-5
Functional Elements . . . . . . . . . . . . . . . . . 1-6
Bus Structure. . . . . . . . . . . . . . . . . . . . . 1-7
Data Bus Description . . . . . . . . . . . . . . . . 1-7
Data Byte Transfer Control Bus Description . . . . 1-8
General Interface Management Bus Description . . 1-9
Device Interface Function Capability . . . . . . . 1-10
Message Types . . . . . . . . . . . . . . . . . . . 1-11
1-4
681XXC GPIB OPERATION. . . . . . . . . . . .
Setting GPIB Operating Parameters . . . . . .
Selecting the Interface Language . . . . . . . .
Response to GPIB Interface Function Messages
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1-13
1-13
1-13
1-13
Chapter 2 - Programming with GPIB Commands
2-1
INTRODUCTION . . . . . . . . . . . . . . . . . . . 2-3
2-2
COMMAND CODES . . . . . . . . . . . . . . . . . 2-3
2-3
DATA INPUT RESTRICTIONS. . . . . . . . . . . . 2-6
2-4
PARAMETER AND DATA ENTRY COMMANDS . . 2-7
Opening a Parameter . . . . . . . . . . . . . . . . 2-7
Data Entry . . . . . . . . . . . . . . . . . . . . . . 2-7
Using the SYZ Command. . . . . . . . . . . . . . 2-13
2-5
CW FREQUENCY COMMANDS . . . . . . . . . . 2-14
2-6
ANALOG AND STEP SWEEP COMMANDS.
Sweep Range . . . . . . . . . . . . . . . . .
Alternate Sweep . . . . . . . . . . . . . . .
Sweep Triggering . . . . . . . . . . . . . . .
Analog/Step Sweep Select . . . . . . . . . .
Special Step Sweep . . . . . . . . . . . . . .
2-7
FREQUENCY MARKER COMMANDS . . . . . . 2-20
2-8
MODULATION COMMANDS. . . . . . . . . . . . 2-22
681XXC PM
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2-15
2-15
2-16
2-16
2-18
2-20
i
Table of Contents (Continued)
Amplitude Modulation . . . . . . . . . . . . . . . 2-22
Frequency Modulation . . . . . . . . . . . . . . . 2-22
Square Wave Modulation . . . . . . . . . . . . . . 2-23
ii
2-9
MEASURE FUNCTION COMMANDS . . . . . . . 2-26
2-10
OUTPUT POWER LEVELING COMMANDS . . . 2-27
Linear or Logarithmic Power Level Selection . . . 2-27
RF Output Power Level Selection . . . . . . . . . 2-27
Alternate Sweep RF Output Power Level Selection2-27
Output Power Leveling . . . . . . . . . . . . . . . 2-27
ALC Power Slope . . . . . . . . . . . . . . . . . . 2-30
Attenuator Decoupling . . . . . . . . . . . . . . . 2-30
2-11
OUTPUT COMMANDS . . . . . . . . . . . . . . . 2-31
2-12
STORED SETUP COMMANDS . . . . . . . . . . . 2-34
2-13
SRQ AND STATUS BYTE COMMANDS . . . . . . 2-36
Status Bytes. . . . . . . . . . . . . . . . . . . . . 2-36
SRQ Generation. . . . . . . . . . . . . . . . . . . 2-36
2-14
CONFIGURATION COMMANDS. . . . . . . . . . 2-41
2-15
GROUP EXECUTE TRIGGER COMMANDS . . . 2-42
2-16
LIST SWEEP COMMANDS . .
Accessing and Editing a List .
List Sweep Triggering . . . .
Generating a List Sweep . . .
2-17
FAST-FREQUENCY-SWITCHING COMMANDS . 2-47
Loading the Frequency Table . . . . . . . . . . . 2-47
2-18
POWER-OFFSET-TABLE COMMANDS . . . . . . 2-51
Loading the Power-Offset Table . . . . . . . . . . 2-51
2-19
USER LEVEL CALIBRATION COMMANDS . . . 2-54
Editing the Table Data . . . . . . . . . . . . . . . 2-58
2-20
MASTER-SLAVE OPERATION COMMANDS . . . 2-62
2-21
SELF TEST COMMAND . . . . . . . . . . . . . . 2-63
2-22
MISCELLANEOUS COMMANDS . . . . . . . . . 2-65
2-23
PROGRAM ERRORS . . . . . . . . . . . . . . . . 2-66
Invalid-Parameter . . . . . . . . . . . . . . . . . 2-66
Syntax . . . . . . . . . . . . . . . . . . . . . . . . 2-66
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2-43
2-43
2-45
2-45
681XXC PM
Table of Contents (Continued)
2-24
RESET PROGRAMMING AND DEFAULT
CONDITIONS . . . . . . . . . . . . . . . . . . . 2-67
2-25
PROGRAMMING EXAMPLES . . . . . . . . . . . 2-68
Appendix A - Index of GPIB Commands
A-1
681XXC PM
INTRODUCTION . . . . . . . . . . . . . . . . . . . A-1
iii/iv
Chapter 1
General GPIB Information
Table of Contents
1-1
SCOPE OF MANUAL . . . . . . . . . . . . . . . . . 1-3
Electronic Manual . . . . . . . . . . . . . . . . . . 1-3
1-2
INTRODUCTION . . . . . . . . . . . . . . . . . . . 1-3
1-3
IEEE-488 INTERFACE BUS DESCRIPTION . . . 1-5
Functional Elements . . . . . . . . . . . . . . . . . 1-6
Bus Structure. . . . . . . . . . . . . . . . . . . . . 1-7
Data Bus Description . . . . . . . . . . . . . . . . 1-7
Data Byte Transfer Control Bus Description . . . . 1-8
General Interface Management Bus Description . . 1-9
Device Interface Function Capability . . . . . . . 1-10
Message Types . . . . . . . . . . . . . . . . . . . 1-11
1-4
681XXC GPIB OPERATION. . . . . . . . . . . .
Setting GPIB Operating Parameters . . . . . .
Selecting the Interface Language . . . . . . . .
Response to GPIB Interface Function Messages
.
.
.
.
1-13
1-13
1-13
1-13
Chapter 1
General GPIB Information
1-1
SCOPE OF MANUAL
This manual provides information for remote operation of the Series
681XXC Synthesized Signal Generator using commands sent from an
external controller via the IEEE-488 General Purpose Interface Bus
(GPIB). It includes the following:
q
q
q
A general description of the GPIB and the bus data transfer and
control functions.
A listing of the IEEE-488 Interface Function Messages recognized by the signal generator with a description of its response.
A complete listing and description of all 681XXC GPIB commands (i.e., Product Specific Commands) that can be used to
control signal generator operation with programming examples.
This manual is intended to be used in conjunction with the Series
681XXC Synthesized Signal Generator Operation Manual, P/N
10370-10333. Refer to that manual for general information about the
681XXC, including equipment set up and front panel (manual mode)
operating instructions.
Electronic
Manual
1-2
INTRODUCTION
This manual is available on CD ROM as an Adobe
Acrobat Portable Document Format (*.pdf) file. The
file can be viewedf using Acrobat Reader, a free program that is included on the CD ROM. The file is
“linked” such that the viewer can choose a topic to
view from the displayed “bookmark” list and “jump”
to the manual page on which the topic resides. The
text can also be word-searched. Contact Anritsu
Customer Service for price and availability.
This chapter provides a general description of the GPIB and the bus
data transfer and control functions. It also contains a listing of the
681XXC’s GPIB interface function subset capability and response to
IEEE-488 interface function messages.
The GPIB information presented in this chapter is general in nature.
For complete and specific information, refer to the following documents: ANSI/IEEE Std 488.1-1987 IEEE Standard Digital Interface
for Programmable Instrumentation and ANSI/IEEE Std 488.2-1987
IEEE Standard Codes, Formats, Protocols and Common Commands.
These documents precisely define the total specification of the mechanical and electrical interface, and of the data transfer and control
protocols.
681XXC PM
1-3
GENERAL GPIB
INFORMATION
IEEE-488 INTERFACE
BUS DESCRIPTION
IE E E -4 8 8 B U S (1 6 L in e s )
D E V IC E A
A b le to ta lk , lis te n ,
a n d c o n tro l
(e .g . C O M P U T E R )
D a ta B u s
( 8 s ig n a l lin e s )
D A T A L IN E S
D E V IC E B
A b le
(e .g .
S IG N
G E N
to ta lk a n d lis te n
6 8 1 X X C
A L
E R A T O R )
D a ta B y te T ra n s fe r
C o n tro l B u s
( 3 s ig n a l lin e s )
H A N D S H A K E L in e s
D E V IC E C
O n ly a b le to lis te n
(e .g . O T H E R
IN S T R U M E N T * * )
G e n e ra l In te rfa c e
M a n a g e m e n t B u s
( 5 s ig n a l lin e s )
M a n a g e m e n t
C O N T R O L L in e s
D E V IC E D
O n ly a b le to ta lk
(e .g . O T H E R
IN S T R U M E N T * * )
D A T A IN P U T /O U T P U T ,
D IO 1 th r u D IO 8
D A V - D A T A V A L ID
N R F D - N O T R E A D Y F O R D A T A *
N D A C - N O T D A T A A C C E P T E D *
IF C
A T
S R
R E
E O
- IN T E
N - A T T
Q - S E R
N - R E M
I - E N D
R F A
E N T
V IC
O T
O R
C E C
IO N
E R E
E E N
ID E N
L E A R
Q U E S T
A B L E
T IF Y
* N E G A T IO N IS R E P R E S E N T E D B Y
L O W S T A T E O N T H E S E T W O L IN E S
* * IF U S E D
Figure 1-1.
1-4
Interface Connections and GPIB Bus Structure
681XXC PM
GENERAL GPIB
INFORMATION
1-3
IEEE-488 INTERFACE
BUS DESCRIPTION
IEEE-488 INTERFACE
BUS DESCRIPTION
The IEEE-488 General Purpose Interface Bus (GPIB) is an instrumentation interface for integrating instruments, computers, printers, plotters, and other measurement devices into systems. The GPIB uses 16
signal lines to effect transfer of information between all devices connected on the bus.
The following requirements and restrictions apply to the GPIB.
q
q
q
q
No more than 15 devices can be interconnected by one contiguous
bus; however, an instrumentation system may contain more than
one interface bus.
The maximum total cumulative cable length for one interface bus
may not exceed twice the number of devices connected (in meters) , or 20 meters—whichever is less.
A maximum data rate of 1 Mb/s across the interface on any signal line.
Each device on the interface bus must have a unique address,
ranging from 00 to 30.
The devices on the GPIB are connected in parallel, as shown in Figure
1-1. The interface consists of 16 signal lines and 8 ground lines in a
shielded cable. Eight of the signal lines are the data lines, DIO 1 thru
DIO 8. These data lines carry messages (data and commands), one
byte at a time, among the GPIB devices. Three of the remaining lines
are the handshake lines that control the transfer of message bytes between devices. The five remaining signal lines are referred to as interface management lines.
The following paragraphs provide an overview of the GPIB including a
description of the functional elements, bus structure, bus data transfer
process, interface management bus, device interface function requirements, and message types.
681XXC PM
1-5
GENERAL GPIB
INFORMATION
IEEE-488 INTERFACE
BUS DESCRIPTION
Functional
Elements
Effective communications between devices on the
GPIB requires three functional elements; a talker, a
listener, and a controller. Each device on the GPIB is
categorized as one of these elements depending on
its current interface function and capabilities.
Talker
A talker is a device capable of sending devicedependent data to another device on the bus when
addressed to talk. Only one GPIB device at a time
can be an active talker.
Listener
A listener is a device capable of receiving devicedependent data from another device on the bus
when addressed to listen. Any number of GPIB
devices can be listeners simultaneously.
Controller
A controller is a device, usually a computer, capable
of managing the operation of the GPIB. Only one
GPIB device at a time can be an active controller.
The active controller manages the transfer of
device-dependent data between GPIB devices by
designating who will talk and who will listen.
System Controller
The system controller is the device that always
retains ultimate control of the GPIB. When the system is first powered-up, the system controller is the
active controller and manages the GPIB. The system controller can pass control to a device, making
it the new active controller. The new active controller, in turn, may pass control on to yet another
device. Even if it is not the active controller, the
system controller maintains control of the Interface
Clear (IFC) and Remote Enable (REN) interface
management lines and can thus take control of the
GPIB at anytime.
1-6
681XXC PM
GENERAL GPIB
INFORMATION
IEEE-488 INTERFACE
BUS DESCRIPTION
Bus
Structure
The GPIB uses 16 signal lines to carry data and
commands between the devices connected to the
bus. The interface signal lines are organized into
three functional groups.
q
q
q
Data Bus (8 lines)
Data Byte Transfer Control Bus (3 lines)
General Interface Management Bus (5 lines)
The signal lines in each of the three groups are designated according to function. Table 1-1 lists these
designations.
Table 1-1.
Interface Bus Signal Line Designations
Signal Line
Name
Bus Type
Function
Data Bus
DIO1–DIO8
Data Input/Output, 1 thru 8
Data Byte
Transfer
Control Bus
DAV
NRFD
NDAC
Data Available
Not Ready For Data
Not Data Accepted
General
Interface
Management
Bus
ATN
IFC
SRQ
REN
EOI
Attention
Interface Clear
Service Request
Remote Enable
End Or Identify
Data Bus
Description
The data bus is the conduit for the transfer of data
and commands between the devices on the GPIB. It
contains eight bi-directional, active-low signal lines
—DIO 1 thru DIO 8. Data and commands are transferred over the data bus in byte-serial, bit-parallel
form. This means that one byte of data (eight bits) is
transferred over the bus at a time. DIO 1 represents
the least-significant bit (LSB) in this byte and
DIO 8 represents the most-significant bit (MSB).
Bytes of data are normally formatted in seven-bit
ASCII (American Standard Code for Information Interchange) code. The eighth (parity) bit is not used.
Each byte placed on the data bus represents either a
command or a data byte. If the Attention (ATN) interface management line is TRUE while the data is
transferred, then the data bus is carrying a bus
command which is to be received by every GPIB device. If ATN is FALSE, then a data byte is being
transferred and only the active listeners will receive
that byte.
681XXC PM
1-7
GENERAL GPIB
INFORMATION
IEEE-488 INTERFACE
BUS DESCRIPTION
1st Data Byte
2nd Data Byte
DIO1-DIO8
(composite)
DAV
Valid
All
Ready
NRFD
None
Accept
NDAC
Figure 1-2.
None
Ready
All
Accept
Not
Valid
All
Ready
None
Accept
Not
Valid
Valid
None
Ready
All
Accept
Typical GPIB Handshake Operation
Data Byte
Transfer
Control Bus
Description
Control of the transfer of each byte of data on the
data bus is accomplished by a technique called the
“three-wire handshake”, which involves the three
signal lines of the Data Byte Transfer Control Bus.
This technique forces data transfers at the speed of
the slowest listener, which ensures data integrity in
multiple listener transfers. One line (DAV) is controlled by the talker, while the other two (NRFD and
NDAC) are wired-OR lines shared by all active listeners. The handshake lines, like the other GPIB
lines, are active low. The technique is described
briefly in the following paragraphs and is depicted
in Figure 1-2. For further information, refer to
ANSI/IEEE Std 488.1.
DAV (Data Valid)
This line is controlled by the active talker. Before
sending any data, the talker verifies that NDAC is
TRUE (active low) which indicates that all listeners
have accepted the previous data byte. The talker
then places a byte on the data lines and waits until
NRFD is FALSE (high) which indicates that all addressed listeners are ready to accept the information. When both NRFD and NDAC are in the proper
state, the talker sets the DAV line TRUE (active
low) to indicate that the data on the bus is valid
(stable).
NRFD (Not Ready For Data)
This line is used by the listeners to inform the
talker when they are ready to accept new data. The
talker must wait for each listener to set the NRFD
1-8
681XXC PM
GENERAL GPIB
INFORMATION
IEEE-488 INTERFACE
BUS DESCRIPTION
line FALSE (high) which they will do at their own
rate. This assures that all devices that are to accept
the data are ready to receive it.
NDAC (Not Data Accepted)
This line is also controlled by the listeners and is
used to inform the talker that each device addressed
to listen has accepted the data. Each device releases
NDAC at its own rate, but NDAC will not go FALSE
(high) until the slowest listener has accepted the
data byte.
General
Interface
Management
Bus
Description
The general interface management bus is a group of
five signal lines used to manage the flow of information across the GPIB. A description of the function of
each of the individual control lines is provided below.
ATN (Attention)
The active controller uses the ATN line to define
whether the information on the data bus is a command or is data. When ATN is TRUE (low), the bus
is in the command mode and the data lines carry
bus commands. When ATN is FALSE (high), the bus
is in the data mode and the data lines carry devicedependent instructions or data.
EOI (End or Identify)
The EOI line is used to indicate the last byte of a
multibyte data transfer. The talker sets the EOI line
TRUE during the last data byte.
The active controller also uses the EOI line in conjunction with the ATN line to initiate a parallel poll
sequence.
IFC (Interface Clear)
Only the system controller uses this line. When IFC
is TRUE (low), all devices on the bus are placed in a
known, quiescent state (unaddressed to talk, unaddressed to listen, and service request idle).
REN (Remote Enable)
Only the system controller uses this line. When
REN is set TRUE (low), the bus is in the remote
mode and devices are addressed either to listen or to
talk. When the bus is in remote and a device is addressed, it receives instructions from the GPIB
rather than from its front panel. When REN is set
FALSE (high), the bus and all devices return to local
operation.
681XXC PM
1-9
GENERAL GPIB
INFORMATION
IEEE-488 INTERFACE
BUS DESCRIPTION
SRQ (Service Request)
The SRQ line is set TRUE (low) by any device requesting service by the active controller.
Device
Interface
Function
Capability
An interface function is the GPIB system element
which provides the basic operational facility through
which a device can receive, process, and send messages. Each specific interface function may only
send or receive a limited set of messages within
particular classes of messages. As a result, a set of
interface functions is necessary to achieve complete
communications among devices on the GPIB.
ANSI/IEEE Std 488.1 defines each of the interface
functions along with its specific protocol.
ANSI/IEEE Std 488.2 specifies the minimum set of
IEEE 488.1 interface capabilities that each GPIB
device must have. This minimum set of interface
functions assures that the device is able to send and
receive data, request service, and repond to a device
clear message. Table 1-2 lists the interface function
capability of the series 681XXC signal generator.
Table 1-2.
681XXC Interface Function Capability
Function
Identifier
681XXC Capability
AH1
Acceptor Handshake
Complete Capability
SH1
Source Handshake
Complete Capability
T6
Talker
No Talk Only (TON)
L4
Listener
No Listen Only (LON)
SR1
Service Request
Complete Capability
RL1
Remote/Local
Complete Capability
PP1
Parallel Poll
Complete Capability
DC1
Device Clear
Complete Capability
DT1
Device Trigger
Complete Capability
Controller Capability
Options
C0, No Capability;
C1, System Controller;
C2, Send IFC and Take Charge;
C3, Send REN;
C28, Send IF Messages
Tri-State Drivers
Three-state bus drivers
C0, C1, C2,
C3, C28
E2
1-10
Function
681XXC PM
GENERAL GPIB
INFORMATION
IEEE-488 INTERFACE
BUS DESCRIPTION
Message
Types
There are three types of information transmitted
over the GPIB—interface function messages,
device-specific commands, and data and instrument
status messages.
Interface Function Messages
The controller manages the flow of information on
the GPIB using interface function messages, usually
called commands or command messages. Interface
function messages perform such functions as initializing the bus, addressing and unaddressing devices,
and setting device modes for remote or local operation.
There are two types of commands—multiline and
uniline. Multiline commands are bytes sent by the
active controller over the data bus (DIO1-DIO8)
with ATN set TRUE. Uniline commands are signals
carried by the individual interface management
lines.
The user generally has control over these commands; however, the extent of user control depends
on the implementation and varies with the specific
GPIB interface hardware and software used with
the external controller.
Device-Specific Commands
These commands are keywords or mnemonic codes
sent by the external controller to control the setup
and operation of the addressed device or instrument. The commands are normally unique to a particular instrument or class of instruments and are
described in its documentation.
Device-specific commands are transmitted over the
data bus of the GPIB to the device in the form of
ASCII strings containing one or more keywords or
codes.They are decoded by the device’s internal controller and cause the various instrument functions
to be performed.
Data and Instrument Status Messages
These messages are sent by the device to the external controller via the GPIB. They contain measurement results, instrument status, or data files that
the device transmits over the data bus in response
to specific requests from the external controller. The
contents of these messages are instrument specific
and may be in the form of ASCII strings or binary
data.
681XXC PM
1-11
GENERAL GPIB
INFORMATION
IEEE-488 INTERFACE
BUS DESCRIPTION
In some cases data messages will be transmitted
from the external controller to the device. For example, messages to load calibration data.
An SRQ (service request) is an interface function
message sent from the device to the external controller to request service from the controller, usually
due to some predetermined status condition or error.
To send this message, the device sets the SRQ line
of the General Interface Management Bus true,
then sends a status byte on the data bus lines.
An SRQ interface function message is also sent by
the device in response to a serial poll message from
the controller, or upon receiving an Output Status
Byte(s) command from the controller. The protocols
associated with the SRQ functions are defined in the
ANSI/IEEE Std 488.2 document.
The manner in which interface function messages
and device-specific commands are invoked in programs is implementation specific for the GPIB interface used with the external controller. Even though
both message types are represented by mnemonics,
they are implemented and used in different ways.
Normally, the interface function messages are sent
automatically by the GPIB driver software in response to invocation of a software function. For example, to send the IFC (Interface Clear) interface
fuction message, one would call the ibsic function of
the National Instruments software driver. On the
other hand, the command *RST (Reset) is sent in a
command string to the addressed device. In the case
of the National Instruments example, this would be
done by using the ibwrt function call.
1-12
681XXC PM
GENERAL GPIB
INFORMATION
1-4
681XXC GPIB
OPERATION
681XXC GPIB
OPERATION
All Series 681XXC Synthesized Signal Generator functions, settings,
and operating modes (except for power on/standby) are controllable using commands sent from an external controller via the GPIB. When in
the remote (GPIB) mode, the Signal Generator functions both as a
listener and a talker. The GPIB interface function capability of the
681XXC is listed in Table 1-2 (page 1-10).
Setting GPIB
Operating
Parameters
The 681XXC leaves the factory with the GPIB address value set to 5 and the data delimiting terminator set to carriage return and line feed (CR/LF). A
different address value can be entered from the
front panel using the Configure GPIB menu. Using
this same menu, the data delimiting terminator can
be changed to carriage return (CR) only. Refer to
Chapter 2 of the Series 681XXC Synthesized Signal
Generator Operation Manual for the procedure.
Selecting the
Interface
Language
Series 681XXC Synthesized Signal Generators with
Option 19 can be remotely operated using one of two
external interface languages—Native or SCPI. The
Native interface language uses a set of 681XXC
GPIB Product-Specific commands to control the
instrument; the SCPI interface language uses a set
of the Standard Commands for Programmable Instruments commands to control the unit. Selecting
which of these external interface languages is to be
used can be done from the front panel using the
Configure GPIB menu. Refer to Chapter 2 of the
Series 681XXC Synthesized Signal Generator
Operation Manual for the procedure.r
Response to
GPIB
Interface
Function
Messages
Table 1-3 (page 1-14) lists the GPIB Interface Function Messages that the 681XXC will recognize and
respond to. With the exception of the Device Clear
and Selected Device Clear messages, these messages affect only the operation of the 681XXC GPIB
interface. The 681XXC response for each message is
indicated.
Interface function messages are transmitted on the
GPIB data lines and interface management lines as
either unaddressed or addressed commands. The
manner in which these messages are invoked in programs is implementation dependent. For programming information, refer to the documentation
included with the GPIB Interface for the external
controller used.
681XXC PM
1-13
GENERAL GPIB
INFORMATION
681XXC GPIB
OPERATION
Table 1-3.
681XXC Response to GPIB Interface Function Messages
Interface Function Message
1-14
Addressed
Command
681XXC Response
Device Clear (DCL)
Selected Device Clear
(SDC)
No
Yes
Resets the 681XXC to its default
state. (Equivalent to sending the
*RST command.)
Go To Local (GTL)
Yes
Returns the 681XXC to local (front
panel) control.
Group Execute Trigger
(GET)
Yes
Executes a string sof commands, if
programmed.
Interface Clear (IFC)
No
Stops the 681XXC GPIB interface
from listening or talking. (The front
panel controls are not cleared.)
Local Lockout (LLO)
No
Disables the front panel menu
RETURN TO LOCAL soft-key.
Remote Enable (REN)
No
Places the 681XXC under remote
(GPIB) control when it has been
addressed to listen.
Serial-Poll Enable (SPE)
No
Outputs the serial-poll status byte.
Serial-Poll Disable (SPD)
No
Disables the serial-poll function.
Parallel-Poll Configure (PPC)
Yes
Responds to a parallel-poll message
(PPOLL) by setting assigned data
bus line to the logical state (1,0) that
indicates its correct SRQ status.
Parallel-Poll Unconfigure
(PPU)
No
Disables the parallel-poll function.
681XXC PM
Chapter 2
Programming with
GPIB Commands
Table of Contents
2-1
INTRODUCTION . . . . . . . . . . . . . . . . . . . 2-3
2-2
COMMAND CODES . . . . . . . . . . . . . . . . . 2-3
2-3
DATA INPUT RESTRICTIONS. . . . . . . . . . . . 2-6
2-4
PARAMETER AND DATA ENTRY COMMANDS . . 2-7
Opening a Parameter . . . . . . . . . . . . . . . . 2-7
Data Entry . . . . . . . . . . . . . . . . . . . . . . 2-7
Using the SYZ Command. . . . . . . . . . . . . . 2-13
2-5
CW FREQUENCY COMMANDS . . . . . . . . . . 2-14
2-6
ANALOG AND STEP SWEEP COMMANDS.
Sweep Range . . . . . . . . . . . . . . . . .
Alternate Sweep . . . . . . . . . . . . . . .
Sweep Triggering . . . . . . . . . . . . . . .
Analog/Step Sweep Select . . . . . . . . . .
Special Step Sweep . . . . . . . . . . . . . .
2-7
FREQUENCY MARKER COMMANDS . . . . . . 2-20
2-8
MODULATION COMMANDS.
Amplitude Modulation . . . .
Frequency Modulation . . . .
Square Wave Modulation . . .
2-9
MEASURE FUNCTION COMMANDS . . . . . . . 2-26
2-10
OUTPUT POWER LEVELING COMMANDS .
Linear or Logarithmic Power Level Selection .
RF Output Power Level Selection . . . . . . .
Alternate Sweep RF Output Power Level
Selection . . . . . . . . . . . . . . . . . . . .
Output Power Leveling . . . . . . . . . . . . .
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2-15
2-15
2-16
2-16
2-18
2-20
2-22
2-22
2-22
2-23
. . 2-27
. . 2-27
. . 2-27
. . 2-27
. . 2-27
Table of Contents (Continued)
ALC Power Slope . . . . . . . . . . . . . . . . . . 2-30
Attenuator Decoupling . . . . . . . . . . . . . . . 2-30
2-11
OUTPUT COMMANDS . . . . . . . . . . . . . . . 2-31
2-12
STORED SETUP COMMANDS . . . . . . . . . . . 2-34
2-13
SRQ AND STATUS BYTE COMMANDS . . . . . . 2-36
Status Bytes. . . . . . . . . . . . . . . . . . . . . 2-36
SRQ Generation. . . . . . . . . . . . . . . . . . . 2-36
2-14
CONFIGURATION COMMANDS. . . . . . . . . . 2-41
2-15
GROUP EXECUTE TRIGGER COMMANDS . . . 2-42
2-16
LIST SWEEP COMMANDS . .
Accessing and Editing a List .
List Sweep Triggering . . . .
Generating a List Sweep . . .
2-17
FAST-FREQUENCY-SWITCHING COMMANDS . 2-47
Loading the Frequency Table . . . . . . . . . . . 2-47
2-18
POWER-OFFSET-TABLE COMMANDS . . . . . . 2-51
Loading the Power-Offset Table . . . . . . . . . . 2-51
2-19
USER LEVEL CALIBRATION COMMANDS . . . 2-54
Editing the Table Data . . . . . . . . . . . . . . . 2-58
2-20
MASTER-SLAVE OPERATION COMMANDS . . . 2-62
2-21
SELF TEST COMMAND . . . . . . . . . . . . . . 2-63
2-22
MISCELLANEOUS COMMANDS . . . . . . . . . 2-65
2-23
PROGRAM ERRORS . . . . . . . . . . . . . . . . 2-66
Invalid-Parameter . . . . . . . . . . . . . . . . . 2-66
Syntax . . . . . . . . . . . . . . . . . . . . . . . . 2-66
2-24
RESET PROGRAMMING AND DEFAULT
CONDITIONS . . . . . . . . . . . . . . . . . . . 2-67
2-25
PROGRAMMING EXAMPLES . . . . . . . . . . . 2-68
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2-43
2-43
2-45
2-45
Chapter 2
Programming with
GPIB Commands
2-1
INTRODUCTION
This chapter provides information for remote operation of the Series
681XXC Synthesized Signal Generator via the GPIB using 681XXC
GPIB commands. All GPIB Product-Specific commands that are accepted and implemented by the 681XXC are listed and described by
function. Sample programs showing usage of the commands are also
included.
2-2
COMMAND CODES
There are over three hundred and fifty GPIB Product-Specific commands that are accepted and implemented by the 681XXC. These
GPIB commands allow the user to program all front panel and menu
functions (except for power on/standby). Each GPIB command is a
two- or three-character mnemonic code that represents an instrument
command or parameter; for example: RST (reset).
Table 2-1, beginning on page 2-4, is a listing of all 681XXC GPIB command mnemonic codes grouped into functional categories. The listing
for each category includes references to the paragraph and page
number in this chapter where a complete description of that group of
commands can be found.
NOTE
A quick way to determine the function of any of the GPIB command codes listed in Table 2-1 is to look up the command code
of interest in Appendix A of this manual. Appendix A is an alphabetical index of all 681XXC GPIB command mnemonic
codes. A brief description of the function of each command is
also included.
681XXC PM
2-3
PROGRAMMING WITH
GPIB COMMANDS
COMMAND
CODES
Table 2-1.
681XXC GPIB Command Codes Listed by Function (1 of 2)
GPIB Command
Group Function
2-4
Command Codes
Para.
Page
Parameter Entry
Commands
F0, F1, F2, F3, F4, F5, F6, F7, F8, F9, M0,
M1, M2, M3, M4, M5, M6, M7, M8, M9,
XL0, XL1, XL2, XL3, XL4, XL5, XL6, XL7,
XL8, XL9, DLF, DFF, DFM, SLF0, SLF1,
SLF2, SLF3, SLF4, SLF5, SLF6, SLF7,
SLF8, SLF9, SLM0, SLM1, SLM2, SLM3,
SLM4, SLM5, SLM6, SLM7, SLM8, SLM9,
SLDF, SDT, SNS, SWT, LOS, PDT, PNS,
AMS, ASD, FMS, PVT, SLP, SOF, SLV,
SLL1, SLL2, EGI, ADD, FRS, LDT, SYZ,
UP, DN, CLO
2-4
2-7
Data Entry/
DataTerminator
Commands
0 thru 9, –, ., ADR, CLR, DB, DM, GH, MH,
KH, HZ, SEC, MS, US, NS, PCT, GV, MV,
KV, DV, PCV, SPS, TMS, VT
2-4
2-11,
2-12
CW Frequency
Commands
CF0, CF1, CF2, CF3, CF4, CF5, CF6,
CF7, CF8, CF9, CM0, CM1, CM2, CM3,
CM4, CM5, CM6, CM7, CM8, CM9, SQF,
SQU, SQD, ACW
2-5
2-14
Analog and Digital
Sweep Commands
SF1, SF3, FUL, DF0, DF1, DF5, DF6,
AFU, AF1, AF3, AD1, AD5, AD6, AUT,
HWT, EXT, TRG, TRS, RSS, SWP, SSP,
LIS, LGS, MAN, DU1, DU0, TSS, SP1,
SP0
2-6
2-15
Frequency Marker
Commands
ME1, ME0, MK0, IM1, VM1
2-7
2-20
Modulation
Commands
AM0, AM1, AM2, AM3, AM4, AM5, AM6,
FM0, FM1, FM3, FM4, FM5, FM6, FMS,
FMW, FML, FMU, P0, SQP, SW0, SW1,
SW2, SW3, SW4, SW5, SW6, XP
2-8
2-22
Measure Function
Commands
AMI, FMD, MOM
2-9
2-26
Output Power
Leveling
Commands
LOG, LIN, L0, L1, L2, L3, L4, L5, L6, L7,
L8, L9, AL0, AL1, AL2, AL3, AL4, AL5,
AL6, AL7, AL8, AL9, RF1, RF0, LO1, LO0,
IL1, DL1, PL1, ELF, ELR, LV0, LSP, AT0,
AT1, ATT(xx), SL0, SL1, EGO
2-10
2-27
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
COMMAND
CODES
Table 2-1.
681XXC GPIB Command Codes Listed by Function (2 of 2)
GPIB Command
Group Function
681XXC PM
Changed: May 1999
Command Codes
Para.
Page
Output Commands
*IDN?, OI, OFL, OFH, OF0, OF1, OF2,
OF3, OF4, OF5, OF6, OF7, OF8, OF9,
OM0, OM1, OM2, OM3, OM4, OM5, OM6,
OM7, OM8, OM9, OL0, OL1, OL2, OL3,
OL4, OL5, OL6, OL7, OL8, OL9, OLO,
ODF, OPD, OPS, OSD, OSS, OST, OAS,
OAB, OAI, OAE, OFS, OFI, OFE, OMM,
OVN, OWT, OSE, OEM, OES, OSB, OSM,
OSR
2-11
2-31
Stored Setup
Commands
SAF, SAM, SM, SSN(M1-9), RCF, RCM,
RSN(M1-9)
2-12
2-34
Service Request
and Status Byte
Commands
ES1, ES0, FB1, FB0, LE1, LE0, MB0,
MB1, MB2, PE1, PE0, SB1, SB0, SE1,
SE0, SQ1, SQ0, UL1, UL0, LS1, LS0, LA1,
LA0, EL1, EL0, II1, II0, CSB
2-13
2-36
Configuration
Commands
BPN, BPP, EP0, EP1, FRS, PPO, PPC,
RC0, RC1, RT0, RT1, RO0, RO1, TR0,
TR1
2-14
2-41
Group Execute
Trigger (GET)
Commands
GTC, GTD, GTF, GTL, GTO, GTS, GTT,
GTU, Y
2-15
2-42
List Sweep
Commands
LST, ELI(xxxx), ELN(x), LF, LP, LIB(xxxx),
LIE(xxxx), AUT, HWT, EXT, TRG, MNT, UP,
DN, LEA, CTL
2-16
2-43
Fast-FrequencySwitching
Commands
ZL(X000-999), ZEL, ZS(X000-999),
ZPN(bbbb),
ZTL(bbbbnnnnD8D8D8.......D8)
2-17
2-47
Power-OffsetTable Commands
PT0, PT1, PTC, PTL
2-18
2-51
User Level
Calibration
Commands
LU0, LU1, LU2, LU3, LU4, LU5, LUS, LUR
2-19
2-54
Master-Slave
Operation
Commands
S0, S1
2-20
2-62
Self Test
Command
TST
2-21
2-63
Miscellaneous
Commands
ADD, CS0, CS1, DS0, DS1, RL, RST, SNR
2-22
2-65
2-5
PROGRAMMING WITH
GPIB COMMANDS
2-3
DATA INPUT
RESTRICTIONS
DATA INPUT
RESTRICTIONS
The 681XXC signal generator does not accept parameter or data entries in an exponential or scientific notation format. The accepted data
formats are as follows:
q
q
A decimal or integer format for entering parameters and data.
A binary-byte format for entering the status byte mask commands (para. 2-13), the RCF and RCM stored-setup commands
(para. 2-12), the ZTL fast-frequency-switching command (para.
2-17), the power-offset-table commands (para. 2-18), and the LUR
user level calibration command (para. 2-19).
Programming Note: The signal generator only recognizes the following 65 characters:
q
q
q
q
q
The 52 upper- and lower-case alphabetic characters. (The
681XXC accepts both upper- and lower-case characters without
distinguishing between the cases).
The minus sign (–).
The comma (,).
The decimal point (.).
The numerals between 0 and 9.
All characters other than the 65 listed above are ignored and can be
interspersed between meaningful characters without ill effect. This
use of other characters can improve readability. For example, the two
command strings below are valid and interchangable.
“F12.754GHF27.792GHSF1SWPMK0L12DM”
“F1=2.754 GH, F2=7.792 GH, SF1, SWP, MK0, L1=2 DM”
2-6
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
2-4
PARAMETER AND DATA
ENTRY COMMANDS
PARAMETER AND DATA
ENTRY COMMANDS
Table 2-2 lists the command mnemonic codes that open parameters for
data entry. The table also provides the range of values permitted for
each parameter and the data terminator mnemonic codes for each. Tables 2-3 and 2-4 (pages 2-11 and 2-12) list the data entry and data terminator command mnemonic codes.
Opening a
Parameter
All of the commands listed in Table 2-2 open a parameter for data entry. Once opened, a parameter
remains open until one of the following occurs:
q
q
q
Data Entry
Another parameter is opened.
A function other than video markers, intensity
markers, or output power leveling is commanded.
The CLO (close open parameter) command is
received.
When a parameter is open for data entry, its value
can be changed as follows:
q
q
By sending a numeric value followed by the appropriate terminator code.
By incrementing or decrementing its value using an associated step size.
NOTE
An appropriate data terminator must be
used to terminate a numeric-parameter entry, and it must immediately follow the numeric value. If it does not, a parameter entry error will result.
The parameter and data entry commands do not affect the Signal Generator’s output unless the parameter being changed is also the current
output parameter. The commands, therefore, may be used to change
the preset values of parameters without altering the 681XXC’s output.
Example: Assume that the 681XXC is executing an F3-F4 sweep from
3 GHz to 10 GHz. Changing the value of F1 to 3 GHz with the command string “F1 3 GH” does not affect the current output of the Signal Generator. However, changing the value of F4 with the command
string “F4 16.01 GH” alters the output of the 681XXC because it
changes the end point of the F3-F4 sweep to 16.01 GHz.
681XXC PM
2-7
PROGRAMMING WITH
GPIB COMMANDS
PARAMETER AND DATA
ENTRY COMMANDS
Table 2-2.
Parameter Entry Commands (1 of 3)
MNEMONIC
CODE
2-8
PARAMETER
VALUES
TERMINATOR
F0
F1
F2
F3
F4
F5
F6
F7
F8
F9
Opens the F0 parameter
Opens the F1 parameter
Opens the F2 parameter
Opens the F3 parameter
Opens the F4 parameter
Opens the F5 parameter
Opens the F6 parameter
Opens the F7 parameter
Opens the F8 parameter
Opens the F9 parameter
Dependent on the
frequency range of
the instrument
GH
MH
KH
HZ
M0
M1
M2
M3
M4
M5
M6
M7
M8
M9
Opens the M0 parameter
Opens the M1 parameter
Opens the M2 parameter
Opens the M3 parameter
Opens the M4 parameter
Opens the M5 parameter
Opens the M6 parameter
Opens the M7 parameter
Opens the M8 parameter
Opens the M9 parameter
Dependent on the
frequency range of
the instrument
GH
MH
KH
HZ
XL0
XL1
XL2
XL3
XL4
XL5
XL6
XL7
XL8
XL9
Opens the L0 parameter
Opens the L1 parameter
Opens the L2 parameter
Opens the L3 parameter
Opens the L4 parameter
Opens the L5 parameter
Opens the L6 parameter
Opens the L7 parameter
Opens the L8 parameter
Opens the L9 parameter
Dependent on the
power level range
of the instrument
DM
(Logarithmic)
VT
(Linear)
DLF
DFF
DFM
Opens the DF parameter
Opens the DF parameter
Opens the DF parameter
Dependent on the
frequency range of
the instrument
GH
MH
KH
HZ
SLF0
SLF1
SLF2
SLF3
SLF4
SLF5
SLF6
SLF7
SLF8
SLF9
Slave Unit Frequencies
Opens the F0 parameter
Opens the F1 parameter
Opens the F2 parameter
Opens the F3 parameter
Opens the F4 parameter
Opens the F5 parameter
Opens the F6 parameter
Opens the F7 parameter
Opens the F8 parameter
Opens the F9 parameter
Dependent on the
frequency range of
the instrument
GH
MH
KH
HZ
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
PARAMETER AND DATA
ENTRY COMMANDS
Table 2-2.
Parameter Entry Commands (2 of 3)
MNEMONIC
CODE
SLM0
SLM1
SLM2
SLM3
SLM4
SLM5
SLM6
SLM7
SLM8
SLM9
681XXC PM
PARAMETER
Slave Unit Frequencies
Opens the M0 parameter
Opens the M1 parameter
Opens the M2 parameter
Opens the M3 parameter
Opens the M4 parameter
Opens the M5 parameter
Opens the M6 parameter
Opens the M7 parameter
Opens the M8 parameter
Opens the M9 parameter
VALUES
TERMINATOR
Dependent on the
frequency range of
the instrument
GH
MH
KH
HZ
SLDF
Opens the DF parameter for
the slave unit
Dependent on the
frequency range of
the instrument
GH
MH
KH
HZ
SDT
Opens the step sweep dwell
time parameter
1 ms to 99 sec
MS
SEC
SNS
Opens the step sweep
number of steps parameter
1 to 10,000
SPS
SWT
Opens the analog sweep,
step sweep, and CW ramp
time parameter
30 ms to 99 sec
MS
SEC
LOS
Opens the level offset
parameter
+100 dB to
–100 dB
PDT
Opens the power sweep
dwell time parameter
1 ms to 99 sec
MS
SEC
PNS
Opens the power sweep
number of steps parameter
1 to 10,000
SPS
AMS
Opens the external AM %/V
sensitivity parameter
0 %/V to 100 %/V
PCV
ASD
Opens the external AM dB/V
sensitivity parameter
0 dB/V to 25 dB/V
DV
FMS
Opens the external FM
sensitivity parameter
±1 kHz/V to
±20 MhzV in
Locked FM and
Unlocked Narrow
FM; ±100 kHz/V to
±100 MHz/V in
Unlocked Wide FM
KV
MV
DB
2-9
PROGRAMMING WITH
GPIB COMMANDS
PARAMETER AND DATA
ENTRY COMMANDS
Table 2-2.
Parameter Entry Commands (3 of 3)
MNEMONIC
CODE
PARAMETER
VALUES
TERMINATOR
PVT
Opens the ALC power slope
pivot point frequency
parameter
Dependent on the
frequency range of
the instrument
GH
MH
KH
HZ
SLP
Opens the ALC power
slope value parameter
0 to 255
SPS
SOF
Opens the frequency offset
parameter for the slave unit
(in a 360B VNA configuration)
Dependent on the
frequency range of
the instrument
GH
MH
KH
HZ
SLV, SLL1
Opens the main power level
parameter (L1) for the slave
unit
Dependent on the
power level range
of the instrument
DM
SLL2
Opens the alternate sweep
power level parameter (L2)
for the slave unit
Dependent on the
power level range
of the instrument
DM
EGI
Opens the Reference Level
DAC setting parameter (in
external power leveling
mode)
0 to 255
SPS
ADD
Opens the GPIB address
parameter
1 to 30
ADR
LDT
Opens the list sweep dwell
time parameter
1 ms to 99s
MS
SEC
FRS
Opens the frequency
scaling reference multiplier
parameter
0.1 to 14
TMS
SYZ
Opens the step-size
parameter for updating
Dependent on the
open parameter
N/A
UP
Increments the open parameter by the step size
N/A
N/A
DN
Decrements the open
parameter by the step size
N/A
N/A
Closes the previously
opened parameter
N/A
N/A
CLO
2-10
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
PARAMETER AND DATA
ENTRY COMMANDS
Table 2-3.
Data Entry Commands
MNEMONIC
CODE
0, 1, 2, 3, 4,
5, 6, 7, 8, 9
Numerals for parameter value entries
–
Change sign of input
.
Decimal point
CLR
681XXC PM
DESCRIPTION
Clear data entry
2-11
PROGRAMMING WITH
GPIB COMMANDS
PARAMETER AND DATA
ENTRY COMMANDS
Table 2-4.
Data Terminator Codes
MNEMONIC
CODE
2-12
DESCRIPTION
ADR
GPIB Address
DB
Decibels (dB)
DM
dBm
GH
GHz
MH
MHz
KH
kHz
HZ
Hertz (Hz)
SEC
Seconds
MS
Milliseconds (ms)
US
Microseconds (ms)
NS
Nanoseconds (ns)
PCT
Percent (%)
GV
GHz per volt (GHz/V)
MV
MHz per volt (MHz/V)
KV
kHz per volt (kHz/V)
DV
Decibel per volt (dB/V)
PCV
Percent per volt (%/V)
SPS
Steps
TMS
Times
VT
Volts
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
PARAMETER AND DATA
ENTRY COMMANDS
Using the
SYZ Command
Each 681XXC parameter has an associated step size
that can be used to increment or decrement its
value. Parameters that have common units share a
common step size. For example, the frequency parameters (F0-F9, M0-M9, and DF) have a common
step size as do the power level parameters (XL0XL9, L0-L9, and Level Offset). Other parameters,
such as analog sweep time, have individual step
sizes.
To set the step size for a parameter, first send the
command code to open the parameter, then send the
SYZ command. Now set the step size by sending a
numeric string with the proper terminator. When
the terminator is received, the step size is accepted
and the original parameter is again open for entry.
Figure 2-1 shows how the SYZ command can be
used to increment a parameter. In this example, the
F1 frequency parameter is set to 4 GHz, the step
size is set to 10 MHz, and F1 frequency is incremented three times by the value of the step size.
F1
4 GH
SYZ
10 MH
UP
UP
UP
Increments F1 from 4.02 GHz to 4.03 GHz.
Increments F1 from 4.01 GHz to 4.02 GHz.
Increments F1 from 4.00 GHz to 4.01 GHz.
Sets a step size of 10 MHz, ends the step-size entry,
and reopens the F1 parameter.
Opens the step-size parameter for F1.
Sets the F1 Parameter to 4 GHz.
Selects the F1 Parameter and opens it for entry.
Figure 2-1.
Using the SYZ (Step Size) Command
681XXC PM
2-13
PROGRAMMING WITH
GPIB COMMANDS
2-5
CW FREQUENCY
COMMANDS
CW FREQUENCY
COMMANDS
Table 2-5 lists the CW frequency command mnemonic codes. These
commands call up each of the 20 preset (or previously set) CW frequencies. Each command causes its associated CW frequency to be
output and opens that frequency’s parameter for data entry.
The command, SQF, accesses the preset frequencies in sequential
order—that is, F0 to F9 and M0 to M9.
Table 2-5.
CW Frequency Commands
MNEMONIC
CODE
2-14
FUNCTION
OPENS FOR ENTRY
CF0
CF1
CF2
CF3
CF4
CF5
CF6
CF7
CF8
CF9
Set CW mode at F0
Set CW mode at F1
Set CW mode at F2
Set CW mode at F3
Set CW mode at F4
Set CW mode at F5
Set CW mode at F6
Set CW mode at F7
Set CW mode at F8
Set CW mode at F9
F0 parameter
F1 parameter
F2 parameter
F3 parameter
F4 parameter
F5 parameter
F6 parameter
F7 parameter
F8 parameter
F9 parameter
CM0
CM1
CM2
CM3
CM4
CM5
CM6
CM7
CM8
CM9
Set CW mode at M0
Set CW mode at M1
Set CW mode at M2
Set CW mode at M3
Set CW mode at M4
Set CW mode at M5
Set CW mode at M6
Set CW mode at M7
Set CW mode at M8
Set CW mode at M9
M0 parameter
M1 parameter
M2 parameter
M3 parameter
M4 parameter
M5 parameter
M6 parameter
M7 parameter
M8 parameter
M9 parameter
SQF
Scan to the next higher preset
CW frequency.
CW frequency parameter
then selected
SQU
Scan up to the next higher preset
CW frequency.
CW frequency parameter
then selected
SQD
Scan down to the next lower preset
CW frequency.
CW frequency parameter
then selected
ACW
Activates the currently scanned
frequency as CW.
CW frequency parameter
then selected
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
ANALOG AND STEP
SWEEP COMMANDS
Programming Note: Signal generator response to a SQF command
depends on the state the instrument is in at the time the command is
received. For example, if the 681XXC is in a CW mode of operation
with the current output frequency open for entry, the SQF command
(1) causes the output to change to the next sequential frequency and
(2) opens that frequency’s parameter for data entry. However, if the instrument is in any other mode of operation, the SQF command causes
it to switch to the last CW frequency that was output and opens that
parameter for data entry.
Figure 2-2 is an example of a CW frequency command string.
CF1
CF6 7 GH
SQF
Closes the F6 parameter. Places the 681XXC at the
preset (or previously set) CW F7 parameter and opens
the F7 parameter for data entry.
Closes the F1 parameter. Places the 681XXC at the
preset (or previously set) CW F6 frequency and opens the F6
parameter for data entry. Sets the F6 frequency to 7 GHz.
Places the 681XXC at the preset (or previously set) CW F1
frequency and opens the F1 parameter for data entry.
Figure 2-2.
2-6
ANALOG AND STEP
SWEEP COMMANDS
Example of a CW Frequency Command String
Table 2-6 (page 2-17) lists the analog and step sweep command mnemonic codes. These commands are divided into five subclasses and are
described in the following paragraphs.
Sweep Range
Seven sweep ranges are available. The SF1 and SF3
commands select the sweep ranges of F1-F2 and
F3-F4 respectively; the FUL command selects a full
band sweep from the Signal Generator’s low frequency limit to its high frequency limit.
The DF0, DF1, DF5, and DF6 commands each select
a symmetrical frequency sweep around F0, F1, F5,
and F6 respectively. The width of the sweep is determined by the DF frequency parameter.
Programming Examples:
Programming “F1 2 GH F2 8 GH SF1” sets F1 to
2 GHz, F2 to 8 GHz, and implements a F1-F2 frequency sweep.
681XXC PM
2-15
PROGRAMMING WITH
GPIB COMMANDS
ANALOG AND STEP
SWEEP COMMANDS
Programming “DLF 6 GH F5 7 GH DF5” sets DF to
6 GHz, F5 to 7 GHz, and implements a F5-DF frequency sweep.
Programming Note:
If the commanded sweep range is invalid, a parameter error (para. 2-23) will be generated, and the output of the Signal Generator will not be altered.
A sweep range is invalid if (1) the analog sweep
start frequency is greater than the stop frequency,
or (2) the DF frequency parameter results in a sweep
that is outside the range of the instrument.
Alternate
Sweep
Six alternate sweep commands are available. If the
681XXC is sweeping when the alternate sweep command is received, the signal generator’s output will
alternate between the commanded sweep and the
sweep then being executed.
Programming Example:
Assume that the 681XXC had been previously programmed and was then executing an F1-F2 sweep.
Programming “AF3” would then activate the F3-F4
sweep and cause it to alternate with the F1-F2
sweep.
Programming Note:
An alternate sweep command will only be recognized when the 681XXC has been programmed to
sweep. It will be ignored at all other times.
Sweep
Triggering
Three modes of sweep triggering are available over
the bus—Automatic, External, and Single. The AUT
command selects automatic sweep triggering; the
HWT command selects external triggerng; the EXT
command selects single sweep triggering.
When automatic sweep triggering is selected, the
sweep continually sweeps from its start frequency
(or power level) to its stop frequency (or power level)
with optimal retrace time.
When external sweep triggering is selected, a single
sweep occurs when triggered by an external TTLcompatible clock pulse to the rear panel AUX I/O
connector.
2-16
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
ANALOG AND STEP
SWEEP COMMANDS
When single sweep triggering is selected, a single
sweep starts when the TRG or TRS command is received. The RSS command resets the sweep to its
start frequency (or power level), whenever the command is received while a single sweep is in progress.
Table 2-6.
Analog and Step Sweep Commands
MNEMONIC
CODE
681XXC PM
FUNCTION
OPENS FOR
ENTRY
SF1
SF3
FUL
DF0
DF1
DF5
DF6
Sweep Range
Selects the F1-F2 sweep mode
Selects the F3-F4 sweep mode
Selects the Full Range sweep mode
Selects the F0-DF sweep mode
Selects the F1-DF sweep mode
Selects the F5-DF sweep mode
Selects the F6-DF sweep mode
None
None
None
None
None
None
None
AFU
AF1
AF3
AD1
AD5
AD6
Alternate Sweep
Selects Full Range alternate sweep
Selects F1-F2 alternate sweep
Selects F3-F4 alternate sweep
Selects F1-DF alternate sweep
Selects F5-DF alternate sweep
Selects F6-DF alternate sweep
None
None
None
None
None
None
AUT
HWT
EXT
TRG
TRS
RSS
Sweep Triggering
Selects Auto Trigger
Selects External Trigger
Selects Single Trigger
Triggers a Single Sweep
Triggers a Single Sweep
Resets a Sweep if in progress
None
None
None
None
None
None
SWP
SSP
LIS
LGS
MAN
DU1
DU0
TSS
Analog/Step Sweep Select
Selects Analog Sweep
Selects Step Sweep (Linear)
Selects Linear Step Sweep (Default Mode)
Selects Logarithmic Step Sweep
Selects Manual (Step) Sweep
Selects Dual Step Sweep mode
Deselects Dual Step Sweep mode
Steps to next point in DU1 mode
None
None
None
None
None
None
None
None
SP1
SP0
Special Step Sweep (Steps Not Equally Spaced)
Selects non-equally spaced step sweep
Deselects non-equally spaced step sweep
None
None
2-17
PROGRAMMING WITH
GPIB COMMANDS
ANALOG AND STEP
SWEEP COMMANDS
Analog/Step
Sweep Select
Five commands are available—SWP selects an analog sweep, SSP and LIS select a linear step sweep,
LGS selects a logarithmic step sweep, and MAN selects a manual (step) sweep. The selected sweep
mode applies to all sweep ranges. Figure 2-3 shows
an example of a sweep command string.
Programming Notes:
Commanding either SWP or SSP does not, by itself,
provide a swept-frequency output. It only determines whether the swept-frequency output will be
an analog or step sweep. If, on the other hand, a frequency sweep is being output by the 681XXC when
one of these commands is received, that sweep will
assume the commanded sweep mode.
The MAN command only provides for setting up the
Signal Generator for a manual sweep. It must be accompanied by the RL command to return the instrument to local (front panel) control in order for the
operator to perform the manual sweep.
SF1
AUT
SWP
EXT
TRS
SSP
TRS
Triggers a single sweep.
Selects linear step sweep.
Triggers a single sweep.
Selects the Single triggering mode.
Selects analog sweep.
Selects Auto triggering.
Selects the F1-F2 sweep range.
Figure 2-3.
2-18
Example of a Sweep Command String
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
ANALOG AND STEP
SWEEP COMMANDS
Dual Step Sweep Mode
The dual step sweep mode provides for generating
synchronized, step sweep outputs from two
681XXCs at a frequency offset. Figure 2-4 shows an
example of dual step sweep programming.
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
190
200
210
220
230
240
250
260
270
280
290
300
310
320
330
340
350
!
“DUAL”
CLEAR
DISP “ENTER # OF STEPS”
INPUT S
DISP “ENTER WAIT TIME [mS]
INPUT W
WAIT 100
DISP “ENTER ‘LO’ START FREQ [GHz]”
INPUT F1
DISP “ENTER ‘LO’ STOP FREQ [GHz]
INPUT F2
DISP “ENTER OFFSET [GHz]
INPUT F3
!
! Initialize both 681XXC’s
!
OUTPUT 705 ;"CF1F1";F1;"GHF2";F2;
“GHSNS”;S;"SPSSSPEXTCLO"
OUTPUT 706 ;"CF1F1";F1+F3;"GHF2";
F2+F3;"GHSNS";S;"SPSSSPEXTCLO"
WAIT 1000
!
! Set both to dual mode and enable
GET to end DWELL
!
SEND 7 ; CMD “%&” DATA “GTLDU1SF1"
EOL
WAIT 100
! Trigger the sweep and wait for
retrace to finish
SEND 7 ; CMD “%&” DATA “TRS” EOL
WAIT 100
! Listen address both 681XXC’s
SEND 7 ; CMD “%&”
FOR C+1 TO S+1
WAIT W
! Trigger both to next point
TRIGGER 7
NEXT C
GOTO 260
Figure 2-4.
681XXC PM
Dual Step Sweep Programming Example
2-19
PROGRAMMING WITH
GPIB COMMANDS
FREQUENCY
MARKER COMMANDS
Special Step
Sweep
This special step sweep provides for a step sweep
that has non-equally spaced steps. It can be used in
any of the available sweep ranges (F1-F2, F3-F4,
Full, F0-DF, F1-DF, F5-DF, and F6-DF). The start frequency in this sweep must be equal to the first frequency programmed with the ZL(X000-999) command
(Table 2-17). The intermediate steps can be programmed to be any frequency within the range of
the programmed sweep.
Programming Note:
The SP1 command can be used with the dual step
sweep mode.
Figure 2-5 shows an example of special step sweep
programming.
For this example, assume a frequency sweep of 3 GHz to 10 GHz, with steps at 3,
6, 8, 9, and 10 GHz.
Sample Coding in BASIC
10 OUTPUT 705; “ZL000 3GH 6GH 8GH 9GH 10GH ZEL”
20 OUTPUT 705; “F1 3GH F2 10GH SNS 4SPS”
30 OUTPUT 705; “SP1 SSP SF1"
Explanation of Code
Line 10 sets up the step frequencies.
Line 20 sets start and stop frequencies and number of steps (frequency points – 1).
Line 30 set the signal generator to SP1, Step Sweep, and F1-F2 sweep range.
Figure 2-5.
2-7
FREQUENCY MARKER
COMMANDS
Special Step Sweep Programming Example
Table 2-7 lists the frequency marker command mnemonic codes. These
commands provide for (1) selecting a CW frequency as a potential
marker, (2) selecting a potential marker as an active marker, and
(3) individually turning markers on and off.
The ME1 command will enable a marker at the current frequency that
is open for update; the ME0 command will disable the same marker. If
a frequency parameter is not open, no action will be taken. The IM1
and VM1 commands will turn on their respective intensity and video
markers. The MK0 command will turn all markers off.
Figure 2-6 shows an example of a frequency marker command string.
2-20
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
FREQUENCY
MARKER COMMANDS
Table 2-7.
Frequency Marker Commands
MNEMONIC
CODE
FUNCTION
OPENS FOR
ENTRY
ME1
Enables a marker at the active frequency
(F0-F9 or M0-M9)
None
ME0
Disables the marker at the active frequency
None
MK0
Turns off markers. Enabled markers remain enabled, but are not active
None
IM1
Turns on the intensity marker mode
None
VM1
Turns on the video marker mode
None
Programming Note: Only one marker mode can be active. Consequently, if the intensity marker mode is active and the video marker
mode is programmed, the displayed markers will change to video
markers. Either mode can be turned off with the MK0 command.
VM1
F1 ME0 F7 ME1 F4 ME1
MK0
Turns both markers off, but leaves the F7 and F4 markers
enabled. Therefore, when VM1 is next programmed, two
frequency markers will reappear on the display — provided
their frequencies are within the 681XXC's sweep range.
Enables the F4 frequency marker.
Enables the F7 frequency marker.
Disables the F1 frequency marker.
Turns on the video-marker mode, and turns off the
intensity-marker mode (if previously enabled).
Figure 2-6.
Example of a Frequency Marker Command String
681XXC PM
2-21
PROGRAMMING WITH
GPIB COMMANDS
2-8
MODULATION
COMMANDS
MODULATION
COMMANDS
Table 2-8 lists the modulation command mnemonic codes. These commands provide for AM, FM, and square wave/pulse modulation of the
signal generator’s output signal.
Amplitude
Modulation
Two AM modes are available—Linear and Log. In
the Linear AM mode, sensitivity is variable from
0 %/V to 100 %/V and the amplitude of the RF output changes linearly as the AM input changes. The
AM1 command turns on the external AM function in
Linear mode. In the Linear AM mode, the AM sensitivity value is changed using the AMS command.
In the Log AM mode, sensitivity is variable from
0 dB/V to 25 dB/V and the amplitude of the RF output changes exponentially as the AM input changes.
The AM2 command turns on the external AM function in Log mode. In the Log AM mode, the AM sensitivity value is changed using the ASD command.
The AM0 command turns off the AM function.
Programming Example:
Programming “AM1 AM3 AM5 AMS 90 PCV” turns
on the AM function in Linear mode, selects the front
panel external AM input, selects an input impedance of 50W, and sets the AM sensitivity to 90 %/V.
Frequency
Modulation
Three FM modes are available—Locked, Unlocked
Narrow, and Unlocked Wide. In the Locked FM
mode, frequency modulation of the output signal is
accomplished by summing the modulating signal
into the FM control path of the YIG phase-lock loop.
Maximum FM deviation is the lesser of ±10 MHz or
Fmod x 300 for 1 kHz to 500 kHz rates.
In the Unlocked FM modes, the YIG phase-lock loop
is disabled to allow for peak FM deviations of up to
100 MHz. In the Unlocked Narrow FM mode, frequency modulation is obtained by applying the
modulating signal to the fine tuning coil of the YIGtuned oscillator. Unlocked Narrow FM mode allows
maximum deviations of ±10 MHz for DC to 500 kHz
rates.
In the Unlocked Wide FM mode, frequency modulation is accomplished by applying the modulating
signal to the main tuning coil of the YIG-tuned oscillator. Unlocked Wide FM mode allows maximum
deviations of ±100 MHz for DC to 100 Hz rates.
2-22
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
MODULATION
COMMANDS
The FM1 (or FMU) command turns on the external
FM function in Unlocked Narrow mode, the FMW
command turns it on in Unlocked Wide mode, and
the FML command turns it on in Locked mode. The
FM sensitivity value is changed using the FMS command. The FM0 command turns off the external FM
function.
Programming Example:
Programming “FMW FM4 FM6 FMS 50 MV” turns on
the external FM function in Unlocked Wide mode,
selects the rear panel FM input, selects an input impedance of 600W, and sets the external FM sensitivity to 50 MHz/V.
Square Wave
Modulation
Two square wave modulation modes are available
—Internal and External. In internal mode, square
wave modulation of the output signal by one of four
modulating signals is available using the following
commands:
q
q
q
q
SW1 turns on modulation at 400 Hz.
SW2 (or SQP) turns on modulation at 1 kHz.
SW3 turns on modulation at 7.8125 kHz.
SW4 turns on modulation at 27.8 kHz.
The XP command turns on the external square
wave/pulse modulation mode. Both the SW0 and P0
commands turn off the square wave modulation
mode.
681XXC PM
2-23
PROGRAMMING WITH
GPIB COMMANDS
MODULATION
COMMANDS
Table 2-8.
2-24
Modulation Commands (1 of 2)
MNEMONIC
CODE
FUNCTION
AM0
Turns off the external AM function. (This is the default mode.)
AM1
Turns on the external AM function in Linear mode.
Disables the external AM function in Log mode, if previously
programmed.
AM2
Turns on the external AM function in Log mode.
Disables the external AM function in Linear mode, if previously
programmed.
AM3
Selects front panel external AM input.
AM4
Selects rear panel external AM input.
AM5
Selects external AM input impedance of 50W.
AM6
Selects external AM input impedance of 600W.
FM0
Turns off the external FM function. (This is the default mode.)
FM1
Turns on the external FM function in Unlocked Narrow mode.
(The signal generator output is not phase-locked.)
Disables the external FM function in Unlocked Wide or Locked
mode, had either mode been previously programmed.
FMW
Turns on the external FM function in Unlocked Wide mode.
(The signal generator output is not phase-locked.)
Disables the external FM function in Unlocked Narrow or
Locked mode, had either mode been previously programmed.
FML
Turns on the external FM function in Locked mode. (The signal
generator output is phase-locked.)
Disables the external FM function in Unlocked Narrow or Unlocked Wide mode, had either mode been previously programmed.
FM3
Selects front panel external FM input.
FM4
Selects rear panel external FM input.
FM5
Selects external FM input impedance of 50W.
FM6
Selects external FM input impedance of 600W.
FMU
Same as FM1. Turns on the external FM function in Unlocked
Narrow mode. (The signal generator output is not phaselocked.)
Disables the external FM function in Unlocked Wide or Locked
mode, had either mode been previously programmed.
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
MODULATION
COMMANDS
Table 2-8.
Modulation Commands (2 of 2)
MNEMONIC
CODE
P0
Turns off the internal or external square wave/pulse modulation
function.
SQP
Turns on internal square wave modulation at 1 kHz.
Disables the external square wave/pulse modulation function, if
previously programmed.
SW0
Same as P0. Turns off the internal or external square
wave/pulse modulation function.
SW1
Turns on internal square wave modulation at 400 Hz.
Disables the external square wave/pulse modulation function, if
previously programmed.
SW2
Same as SQP. Turns on internal square wave modulation at
1 kHz.
Disables the external square wave/pulse modulation function, if
previously programmed.
SW3
Turns on internal square wave modulation at 7.8125 kHz.
Disables the external square wave/pulse modulation function, if
previously programmed.
SW4
Turns on internal square wave modulation at 27.8 kHz.
Disables the external square wave/pulse modulation function, if
previously programmed.
SW5
Selects front panel external square wave input.
SW6
Selects rear panel external square wave input.
XP
681XXC PM
FUNCTION
Turns on the external square wave/pulse modulation function.
Disables the internal square wave modulation function, if
previously programmed.
2-25
PROGRAMMING WITH
GPIB COMMANDS
2-9
MEASURE FUNCTION
COMMANDS
MEASURE
FUNCTION COMMANDS
Table 2-9 lists the measure function commands. These commands provide for measuring the following:
q
q
The actual modulation depth of the RF output signal, as caused
by an external AM signal connected to either the front panel or
rear panel AM IN connector.
The actual frequency deviation of the RF output signal, as caused
by an external FM signal connected to either the front panel or
rear panel FM IN connector.
Table 2-9.
Measure Function Commands
MNEMONIC
CODE
2-26
FUNCTION
AMI
Turns on the AM Measurement mode. In this mode, the signal
generator measures the voltage of the external modulating signal and calculates the modulation depth of the RF output signal.
The measurement results will be sent to the controller upon receipt of the OMM command (Table 2-11).
When the AMI command is received, measurements will
continue to be taken until the mode is exited by receipt of the
MOM command.
FMD
Turns on the FM Measurement mode. In this mode, the signal
generator measures the voltage of the external modulating signal and calculates the peak frequency deviation of the RF output signal.
The measurement results will be sent to the controller upon receipt of the OMM command (Table 2-11).
When the FMD command is received, measurements will
continue to be taken until the mode is exited by receipt of the
MOM command.
MOM
Turns off the AM and FM measurement modes.
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
2-10
OUTPUT POWER
LEVELING COMMANDS
OUTPUT POWER
LEVELING COMMANDS
Table 2-10 lists the output power leveling command mnemonic codes.
These commands provide for (1) selecting linear or logarithmic power
level operation, (2) selecting an RF output power level, (3) leveling the
output power and (4) turning the output power leveling off. In addition, commands are provided for the level offset, power level sweep,
ALC power slope, and step attenuator decoupling functions. Figure 2-7
(page 2-30) shows an example of an output power level command
string.
Linear or
Logarithmic
Power Level
Selection
Power level operations can be linear or logarithmic.
The command, LOG, selects logarithmic power level
operation. In logarithmic mode, power level entries
and outputs are in dBm and power level sweeps are
logarithmic. This is the default mode.
The command, LIN, selects linear power level operation. In linear mode, power level entries and outputs
are in mV and power level sweeps are linear.
RF Output
Power Level
Selection
The commands, L0 thru L9, call up each of the preset (or previously set) output power levels. Each
command causes its associated RF power level to be
output and opens that power level’s parameter for
data entry. Each command will also deselect any
other previously programmed power level and will
turn off a power level sweep, if active.
Alternate
Sweep RF
Output
Power Level
Selection
In the alternate sweep mode, the commands, AL0
thru AL9, call up each of the preset (or previously
set) L0 to L9 output power levels. Each command
causes its associated RF power level to be output
during the alternate sweep. Each command will also
deselect any other previously programmed alternate
sweep power level. The commands do not open the
L1 to L9 power level parameters for data entry. Use
the commands, XL0 thru XL9 or L0 thru L9, to enter
new power level values.
Output
Power
Leveling
There are three output power leveling modes of operation—internal, external (detector or power meter), and fixed gain (leveling off). The IL1 command
selects the internal leveling mode. In this mode, a
signal from an internal level detector is used to level
the output power. This is the default mode.
The DL1 command selects the external (detector)
leveling mode; the PL1 command selects the external (power meter) leveling mode. In this mode, the
output power is leveled using a signal from an exter-
681XXC PM
2-27
PROGRAMMING WITH
GPIB COMMANDS
OUTPUT POWER
LEVELING COMMANDS
nal detector (power meter) connected to the EXTERNAL ALC IN connector. In the external power
leveling mode, the EGI command provides for entering a setting for the Reference Level DAC to control
the ALC gain. The LV0 command selects the fixed
gain (leveling off) mode. Each command will also deselect any other previously programmed output
power leveling mode.
Programming Example:
Programming “PL1 EGI 140 SPS” selects external
leveling of the output power using a signal from an
external power meter and sets the Reference Level
DAC to 140.
Table 2-10.
Power Leveling Commands (1 of 2)
MNEMONIC
CODE
2-28
FUNCTION
OPENS FOR
ENTRY
LOG
Selects logarithmic power level operation.
(This is the default mode.)
None
LIN
Selects linear power level operation.
None
L0
L1
L2
L3
L4
L5
L6
L7
L8
L9
Set RF output power level to L0
Set RF output power level to L1
Set RF output power level to L2
Set RF output power level to L3
Set RF output power level to L4
Set RF output power level to L5
Set RF output power level to L6
Set RF output power level to L7
Set RF output power level to L8
Set RF output power level to L9
L0
L1
L2
L3
L4
L5
L6
L7
L8
L9
AL0
AL1
AL2
AL3
AL4
AL5
AL6
AL7
AL8
AL9
Set alternate sweep RF output level to L0
Set alternate sweep RF output level to L1
Set alternate sweep RF output level to L2
Set alternate sweep RF output level to L3
Set alternate sweep RF output level to L4
Set alternate sweep RF output level to L5
Set alternate sweep RF output level to L6
Set alternate sweep RF output level to L7
Set alternate sweep RF output level to L8
Set alternate sweep RF output level to L9
None
None
None
None
None
None
None
None
None
None
RF1
Turns on the RF output. (This is the default
mode.)
None
RF0
Turns off the RF output.
None
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
OUTPUT POWER
LEVELING COMMANDS
Table 2-10.
Power Leveling Commands (2 of 2)
MNEMONIC
CODE
OPENS FOR
ENTRY
LO1
Turns on the Level Offset function. The value of
the Level Offset parameter is added to the level
measured by the internal leveling loop. The resultant power level value is displayed.
None
LO0
Turns off the Level Offset function.
None
IL1
Selects internal leveling of the output power.
(This is the default mode.)
Deselects the DL1 or PL1 leveling modes, if
previously programmed.
None
DL1
Selects external leveling of the output power,
using a signal from an external detector connected to the EXTERNAL ALC IN connector.
Deselects the IL1 or PL1 leveling modes, if previously programmed.
None
PL1
Selects external leveling of the output power using a signal from an external power meter connected to the EXTERNAL ALC IN connector.
Deselects the IL1 and DL1leveling modes, if
previously programmed.
None
ELF
Selects front panel external leveling input.
None
ELR
Selects rear panel external leveling input.
None
LV0
Turns off leveling of the output power.
None
LSP
Selects the Power Sweep mode. The power
level will sweep as determined by the preset (or
previously set) dwell-time and number-of-steps
parameters.
None
AT1
Selects ALC step attenuator decoupling.
None
AT0
Deselects ALC step attenuator decoupling.
None
Sets step attenuator value to xx (´10 dB) in the
ALC step attenuator decouple mode. xx is an
unsigned integer between 00 (0 dB attenuation)
and 11 (110 dB attenuation).
None
SL1
Turns on the ALC power slope function.
None
SL0
Turns off the ALC power slope function.
None
EGO
Outputs the value of the Reference Level DAC
setting in external power leveling mode.
None
ATT(xx)
681XXC PM
FUNCTION
2-29
PROGRAMMING WITH
GPIB COMMANDS
OUTPUT POWER
LEVELING COMMANDS
ALC Power
Slope
The ALC power slope function provides for linearly
increasing or decreasing output power as the frequency increases to compensate for system, cable,
and waveguide variations due to changes in frequency. The SL1 command turns on the ALC power
slope function. The power slope value is changed using the SLP command and the pivot point frequency
is changed using the PVT command. The SL0 command turns off the ALC power slope function.
Programming Example:
Programming “SL1 SLP 128 SPS PVT 2.0 GH”
turns on the ALC power slope function and sets the
power slope value to 128 and the pivot point frequency to 2 GHz.
Attenuator
Decoupling
The attenuator decoupling function provides for decoupling of the step attenuator (if equipped) from
the ALC system. The AT1 command decouples the
step attenuator, the ATT(xx) command provides for
setting the step attenuator value for 0 to 110 dB in
10 dB increments, and the AT0 command deselects
the attenuator decoupling function.
Programming Example:
Programming “AT1 ATT08” decouples the step
attenuator from the ALC system and sets the step
attenuator value to 80 dB.
RF0
L1 2 DM
L2 12 DM
PNS 10 SPS
LSP
RF1
Turns the RF output on.
Selects a level sweep.
Selects a power sweep and 10 steps.
Selects Level 2 and sets it for 12 dBm.
Selects Level 1 and sets it for 2 dBm.
Turns the RF output off.
Figure 2-7.
2-30
Example of an Output Power Level Command String
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
2-11
OUTPUT COMMANDS
OUTPUT
COMMANDS
Table 2-11 lists the output command mnemonic codes. These commands provide for the output of data from the signal generator to the
controller. Figure 2-8 (page 2-34) shows examples of output command
programming.
Table 2-11.
Output Commands (1 of 4)
MNEMONIC
CODE
681XXC PM
FUNCTION
*IDN?
Causes the signal generator to return an identification string in
IEEE-488.2 specified <NR1> format (four fields separated by
commas). The fields are:<Manufacturer>, <Model>, <Serial #>,
<Firmware revision level>; where the actual model number,
serial number, and firmware version of the 681XXC will be
passed.
OI
Causes the signal generator to identify itself by sending the
following parameter information over the bus; model number,
low-end frequency, high-end frequency, minimum output power
level, maximum output power level, software revision number,
serial number, model prefix (A or B), and series (1 or 2). This
command can be used to send parameter information to the
controller automatically, thus relieving the operator from having
to input the information manually. The string is 36 characters
long.
OFL
Returns the low-end frequency value (in MHz) to the controller.
OFH
Returns the high-end frequency value(in MHz) to the controller.
OF0
Returns the F0 frequency value (in MHz) to the controller.
OF1
Returns the F1 frequency value (in MHz) to the controller.
OF2
Returns the F2 frequency value (in MHz) to the controller.
OF3
Returns the F3 frequency value (in MHz) to the controller.
OF4
Returns the F4 frequency value (in MHz) to the controller.
OF5
Returns the F5 frequency value (in MHz) to the controller.
OF6
Returns the F6 frequency value (in MHz) to the controller.
OF7
Returns the F7 frequency value (in MHz) to the controller.
OF8
Returns the F8 frequency value (in MHz) to the controller.
OF9
Returns the F9 frequency value (in MHz) to the controller.
OM0
Returns the M0 frequency value (in MHz) to the controller.
OM1
Returns the M1 frequency value (in MHz) to the controller.
2-31
PROGRAMMING WITH
GPIB COMMANDS
OUTPUT
COMMANDS
Table 2-11.
Output Commands (2 of 4)
MNEMONIC
CODE
2-32
FUNCTION
OM2
Returns the M2 frequency value (in MHz) to the controller.
OM3
Returns the M3 frequency value (in MHz) to the controller.
OM4
Returns the M4 frequency value (in MHz) to the controller.
OM5
Returns the M5 frequency value (in MHz) to the controller.
OM6
Returns the M6 frequency value (in MHz) to the controller.
OM7
Returns the M7 frequency value (in MHz) to the controller.
OM8
Returns the M8 frequency value (in MHz) to the controller.
OM9
Returns the M9 frequency value (in MHz) to the controller.
OL0
Returns the L0 power value (in dBm when in log mode; in mV
when in linear mode) to the controller.
OL1
Returns the L1 power value (in dBm when in log mode; in mV
when in linear mode) to the controller.
OL2
Returns the L2 power value (in dBm when in log mode; in mV
when in linear mode) to the controller.
OL3
Returns the L3 power value (in dBm when in log mode; in mV
when in linear mode) to the controller.
OL4
Returns the L4 power value (in dBm when in log mode; in mV
when in linear mode) to the controller.
OL5
Returns the L5 power value (in dBm when in log mode; in mV
when in linear mode) to the controller.
OL6
Returns the L6 power value (in dBm when in log mode; in mV
when in linear mode) to the controller.
OL7
Returns the L7 power value (in dBm when in log mode; in mV
when in linear mode) to the controller.
OL8
Returns the L8 power value (in dBm when in log mode; in mV
when in linear mode) to the controller.
OL9
Returns the L9 power value (in dBm when in log mode; in mV
when in linear mode) to the controller.
OLO
Returns the Level Offset power value (in dB when in log mode;
in mV when in linear mode) to the controller.
ODF
Returns the DF frequency value (in MHz) to the controller.
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
OUTPUT
COMMANDS
Table 2-11.
Output Commands (3 of 4)
MNEMONIC
CODE
681XXC PM
FUNCTION
OPD
Returns the dwell time of the power sweep (in ms) to the
controller.
OPS
Returns the number-of-steps of the power sweep to the
controller.
OSD
Returns the dwell time of the step sweep (in ms) to the
controller.
OSS
Returns the number-of-steps of the step sweep to the
controller.
OST
Returns the sweep time value (in ms) to the controller.
OAS
Returns the external AM sensitivity value (in %/V) to the
controller.
OAB
Returns the external AM sensitivity value (in dB) to the
controller.
OAI
Returns the external AM impedance value (in W) to the
controller
OAE
Returns the name of the AM source (“FRONT”, “REAR”) to the
controller.
OFS
Returns the external FM sensitivity value (in MHz/V) to the
controller.
OFI
Returns the external FM impedance value (in W) to the
controller.
OFE
Returns the name of the FM source (“FRONT”, “REAR”) to the
controller.
OMM
1. Returns the AM depth measurement value (in %) to the
controller, when the AMI command either has been or is also
programmed.
2. Retruns the FM deviation measurement value (in MHz) to
the controller, when the FMD command either has been or is
also programmed.
OVN
Returns the ROM version number to the controller.
OWT
Returns the GPIB termination status to the controller. (0=CR;
1=CRLF)
OSE
Returns the last GPIB syntax error to the controller.
2-33
PROGRAMMING WITH
GPIB COMMANDS
STORED SETUP
COMMANDS
Table 2-11.
Output Commands (4 of 4)
MNEMONIC
CODE
FUNCTION
OEM
Returns the Extended SRQ Mask bytes (3 binary bytes) to the
controller.
OES
Returns the GPIB Status bytes (3 binary bytes) to the
controller.
OSB
Returns the Primary GPIB Status byte to the controller.
OSM
Returns the Primary SRQ Mask byte to the controller.
OSR
Returns the self-test results (6 binary bytes) to the controller.
760 OUTPUT 705;"OF1"
770 ENTER 705;A
780 PRINT “F1 is set at ”;A;" MHz"
1050 OUTPUT 705;"OSS"
1060 ENTER 705;A
1070 PRINT “Step Sweep has ”;A;" Steps"
Figure 2-8.
2-12
STORED SETUP
COMMANDS
Output Command Programming Examples
Table 2-12 lists the stored setup command mnemonic codes. These
commands provide for saving instrument setups and recalling them
for use.
A current instrument setup can be saved to internal setup memory using the SSN(M1 to 9) command, where M = memory locations 1 to 9. Up
to nine instrument setups can be stored in this manner. The command
RSN(M1 to 9) recalls a stored instrument setup from internal setup
memory locations 1 to 9.
If more than nine instrument setups are needed, or if it is desirable to
store the setups in the controller instead of the signal generator memory, the 681XXC can be commanded to output and accept stored setups
over the bus.
The SAF command outputs the current instrument setup to the controller in a 4100-byte (approximately) binary data string. The controller stores the instrument setup. The RCF command readies the signal
generator to receive a new instrument setup recalled from the control-
2-34
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
STORED SETUP
COMMANDS
ler. Figure 2-9 shows an example of SAF and RCF command programming.
The SAM and RCM commands perform the same functions as described for the SAF and RCF commands, except that all of the stored
instrument setups are included in the binary data string along with
the current instrument setup. For these commands, the binary data
string is approximately 41000 bytes long.
Table 2-12.
Stored Setup Commands
MNEMONIC
CODE
FUNCTION
SAF
Outputs the current instrument setup to the controller.
SAM
Outputs both the current instrument setup and all stored instrument setups to the controller.
SM
SSN(M1-9)
Recalls the next stored instrument setup in sequence.
Saves the current instrument setup to internal setup memory
location M, where M = 1 to 9.
RCF
Readies the 681XXC to receive a new instrument setup recalled from the controller.
RCM
Readies the 681XXC to receive a new instrument setup and
new stored setups recalled from the controller.
RSN(M1-9)
Recalls the instrument setup stored in internal setup memory
location M, where M = 1 to 9.
Programming Note: The SAF and SAM commands output binary
data. The data string is terminated with “EOI” on the last byte sent
(no CR or LF is sent).
10 DIM A$ [300]
20 OUTPUT 705; “SAF”
30 ENTER 705 USING “#%, #%K”; A$ (Requires EOI
to be the terminator of the read.)
40 OUTPUT 705; “RCF”; A$ (A$ must follow the SAF.)
Figure 2-9.
681XXC PM
SAF and RCF Commands Programming Example
2-35
PROGRAMMING WITH
GPIB COMMANDS
2-13
SRQ AND STATUS
BYTE COMMANDS
SRQ AND STATUS
BYTE COMMANDS
Table 2-13 (page 2-38) lists the Service Request (SRQ) and Status Byte
command mnemonic codes. These commands enable the signal generator to request service from the controller when certain, predefined conditions exist.
Status Bytes
The 681XXC has three GPIB status bytes—the primary and two extended status bytes. Figure 2-10
shows the three status bytes and identifies the
status reporting function of each status byte bit.
Each status reporting bit, with the exception of primary status byte bit 6 (SRQ), is set when the condition on which it reports is detected. These changes
in status byte bit settings can be read by the controller as follows:
q
q
SRQ
Generation
The contents of the primary status byte is returned to the controller in response to a serial
poll or the OSB command.
The contents of the primary status byte and
the two extended status bytes are returned to
the controller in response to the OES command. Figure 2-11 (page 2-40) shows an example of OES command programming.
The Signal Generator can generate GPIB service requests (SRQs) to report instrument status and syntax errors to the controller. The signal generator
will generate an SRQ if:
1. The SRQ generation function has been enabled
using the SQ1 command and,
2. One (or more) of the status reporting functions is
true and,
3. The primary status byte bit associated with the
true status reporting function has been enabled.
Bits in the primary status byte can be enabled by either of two methods. The first uses the FB1/FB0,
ES1/ES0, UL1/UL0, LE1/LE0, PE1/PE0, SE1/SE0,
and SB1/SB0 commands, described in Table 2-13, to
individually enable or disable each bit. The second
method uses a single 8-bit status byte mask (MB0)
to enable any or all of the primary status byte bits.
Figure 2-12 (page 2-40) shows examples of status
byte mask programming.
2-36
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
SRQ AND STATUS
BYTE COMMANDS
NOTE
All status byte bits are latched except for those indicated with the “*”. Once
set, an OES or OSB command must be received before the condition will
be reset. The primary status byte bit 6 (SRQ) is cleared by a serial poll
only.
Primary Status Byte
Extended
Status
Byte 2
SRQ
Syntax
Error
Parameter
Range
Error
Lock
Error
RF
Unleveled
End
of
Sweep
Extended
Status
Byte 1
Bit 7
(128)
Bit 6
(64)
Bit 5
(32)
Bit 4
(16)
Bit 3
(8)
Bit 2
(4)
Bit 1
(2)
Bit 0
(1)
Primary status byte bit 0 is set whenever one of the status conditions reported by
an extended status byte 1 is true and the associated status bit is enabled. This
bit is cleared when the controller sends the OES command.
Primary status byte bit 7 is set whenever one of the status conditions reported by
an extended status byte 2 is true and the associated status bit is enabled. This
bit is cleared when the controller sends the OES command.
Primary status byte bit 6 (SRQ) is not maskable. This bit is set by the SQ1 command and cleared by a serial poll.
Extended Status Byte 1
RF*
Leveled
Not
Used
Not
Used
Not
Used
RF*
Locked
Bit 7
(128)
Bit 6
(64)
Bit 5
(32)
Bit 4
(16)
Bit 3
(8)
Self Test Modulation
Completed
Error
Bit 2
(4)
Bit 1
(2)
Self Test
Failed
Bit 0
(1)
Extended status byte 1 bits are enabled by the extended status byte 1 mask
command, MB1.
Extended status byte 1 bit 0 (SelfTest Failed) and bit 2 (Self Test Complete)
should not be unmasked at the same time.
Extended status byte 1 bit 3 (RF Locked) is only used with the Model 360B interface. The setting of this bit is blocked or unblocked by the commands, LS0 and
LS1 (See Table 2-13).
The setting of extended status byte 1 bit 7 (RF Leveled) is blocked or unblocked
by the commands LA0 and LA1 (See Table 2-13).
Extended Status Byte 2
Parameter* Calibrate
Changed Function
Finished
Bit 7
(128)
Bit 6
(64)
Not
Used
RF*
Unlocked
Crystal
Oven
Failure
Calibrate
Function
Failed
Not
Used
Not
Used
Bit 5
(32)
Bit 4
(16)
Bit 3
(8)
Bit 2
(4)
Bit 1
(2)
Bit 0
(1)
Extended status byte 2 bits are enabled by the extended status byte 2 mask
command, MB2.
The setting of extended status byte 2 bit 4 (RF Unlocked) is blocked or unblocked by the commands, EL0 and EL1 (See Table 2-13).
Extended status byte 2 bit 7 (Parameter Changed) is only used with the Model
56100A interface. The setting of this bit is blocked or unblocked by the commands, II0 and II1 (See Table 2-13).
Figure 2-10.
681XXC PM
Primary and Extended Status Bytes
2-37
PROGRAMMING WITH
GPIB COMMANDS
SRQ AND STATUS
BYTE COMMANDS
Table 2-13.
SRQ and Status Byte Commands (1 of 2)
MNEMONIC
CODE
2-38
FUNCTION
ES1
Enables an SRQ to be generated when Primary Status Byte bit
1 (End of Sweep) is set and SQ1 has been programmed.
ES0
Inhibits an SRQ from being generated when the End of Sweep
bit is set. This is the default mode.
FB1
Enables an SRQ to be generated when Primary Status Byte bit
0 (Extended Status Byte 1) is set and SQ1 has been programmed. The Extended Status Byte 1 bit is set whenever one
(or more) of the unmasked status reporting functions in Extended Status Byte 1 is true.
FB0
Inhibits an SRQ from being generated when the Extended
Status Byte 1 bit is set. This is the default mode.
LE1
Enables an SRQ to be generated when Primary Status Byte bit
3 (Lock Error) is set and SQ1 has been programmed.
LE0
Inhibits an SRQ from being generated when the Lock Error bit
is set. This is the default mode.
MB0
Sets an 8-bit data mask that is used to enable specific bits of
the Primary Status Byte (Figure 2-12). This enables any or all
of the bits (except for bit 6) in the Primary Status Byte to generate an SRQ using one 8-bit byte. This command can be
equivalent to sending ES1, FB1, LE1, PE1, SE1, SB1, and
UL1.
MB1
Sets the enable mask byte for Extended Status Byte 1.
MB2
Sets the enable mask byte for Extended Status Byte 2.
PE1
Enables an SRQ to be generated when Primary Status Byte bit
4 (Parameter Range Error) is set and SQ1 has been programmed.
PE0
Inhibits an SRQ from being generated when the Parameter
Range Error bit is set. This is the default mode.
SB1
Enables an SRQ to be generated when Primary Status Byte bit
7 (Extended Status Byte 2) is set and SQ1 has been programmed. The Extended Status Byte 2 bit is set whenever one
(or more) of the unmasked status reporting functions in Extended Status Byte 2 is true.
SB0
Inhibits an SRQ from being generated when the Extended
Status Byte 2 bit is set. This is the default mode.
SE1
Enables an SRQ to be generated when Primary Status Byte bit
5 (Syntax Error) is set and SQ1 has been programmed.
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
SRQ AND STATUS
BYTE COMMANDS
Table 2-13.
SRQ and Status Byte Commands (2 of 2)
MNEMONIC
CODE
SE0
Inhibits an SRQ from being generated when the Syntax Error
bit is set. This is the default mode.
SQ1
Enables the SRQ generation function. This command allows a
status reporting function, that is true and enabled, to pull the
SRQ line LOW (true) and request service from the controller.
SQ0
Disables the SRQ generation function. This is the default
mode.
UL1
Enables an SRQ to be generated when Primary Status Byte bit
2 (RF Unleveled) is set and SQ1 has been programmed.
UL0
Inhibits an SRQ from being generated when the RF Unleveled
bit is set. This is the default mode.
LS1
Unblocks updating of the Extended Status Byte 1 bit 3 (RF
Locked). This bit is only used with the Model 360B interface.
LS0
Disables updating of the Extended Status Byte 1 bit 3. This is
the default setting.
LA1
Unblocks updating of the Extended Status Byte 1 bit 7 (RF
Leveled)
LA0
Blocks updating of the Extended Status Byte 1 bit 7. This is the
default setting.
EL1
Unblocks updating of the Extended Status Byte 2 bit 4 (RF Unlocked).
EL0
Blocks updating of the Extended Status Byte 2 bit 4. This is the
default setting because it is normal for the RF to be momentarily unlocked during sweeps and sweep retrace.
II1
Unblocks updating of the Extended Status Byte 2 bit 7 (Parameter Changed). This bit is only used with the Model 56100A
interface. This bit is cleared when the 56100A sends the OCP
command (Output Last Parameter Changed).
II0
Disables updating of the Extended Status Byte 2 bit 7. This is
the default setting.
CSB
681XXC PM
FUNCTION
Clears all GPIB status bytes.
2-39
PROGRAMMING WITH
GPIB COMMANDS
SRQ AND STATUS
BYTE COMMANDS
OUTPUT 705; “OES”
ENTER 705 USING “#, B”; A, B, C
MAIN = A
1 EXT = B
2 EXT = C
Figure 2-11.
OES Command Programming Example
The 681XXC has a software mask that permits manipulation of the three status bytes over the bus. This manipulation is accomplished by sending the command codes MB0, MB1, MB2, or all three at once, followed by an argument that assigns an
on/off condition for each bit in the byte. Two examples are shown below:
EXTENDED STATUS BYTE 2
0
1
CALIBRATE FUNCTION FAILED
2
CRYSTAL OVEN FAILURE
3
RF UNLOCKED
4
5
CALIBRATE FUNCTION FINISHED
6
PARAMETER CHANGED
7
"1"
"2"
"4"
"8"
OR
0
0
0
0
0
1
0
1
2
1
1
3
1
0
4
0
0
5
0
0
6
0
7
0
EXAMPLE #1
"16"
PRIMARY
STATUS
BYTE
BIT 7
"32"
"64"
"128"
EXAMPLE #2
MASK BYTE 2
EXAMPLE #1:
“MB2" (CHR $(24))
Sets bits 3 and 4 in Mask Byte 2 to 1 and all other bits to 0, thus enabling bits 3 and 4 in Extended Status Byte 2 to be
read from the bit 7 position of the Primary Status Byte.
EXAMPLE #2:
“MB2" (CHR $(12))
Sets bits 2 and 3 in Mask Byte 2 to 1 and all other bits to 0, thus enabling bits 2 and 3 in Extended Status Byte 2 to be
read from the bit 7 position of the Primary Status Byte.
Figure 2-12.
2-40
Status Byte Mask Programming Examples
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
2-14
CONFIGURATION
COMMANDS
CONFIGURATION
COMMANDS
Table 2-14 lists the configuration command mnemonic codes. These
commands permit selection/setting of the following system configuration items via the bus:
q
q
q
q
q
q
q
q
A +5V or –5V level for the rear panel retrace and bandswitch
blanking outputs.
A TTL-low or TTL-high signal to turn RF on during square
wave/pulse moduation.
Setting the frequency scaling reference multiplier value.
Normally-open or normally-closed contacts on the internal penlift
relay.
RF on or RF off during frequency switching in CW, step sweep,
and list sweep modes.
RF on or RF off during sweep retrace.
RF on or RF off at reset.
40 dB or 0 dB of attenuation when RF is switched off in units
with a step attenuator (Option 2).
The system configuration selections made with GPIB commands remain in effect when the instrument is returned to local control.
Table 2-14.
Configuration Commands (1 of 2)
MNEMONIC
CODE
681XXC PM
Changed: May 1999
FUNCTION
BPN
Selects a –5V level for the retrace and bandswitch blanking
outputs. (The retrace blanking output signal is available at pin 6
of the AUX I/O connector; the bandswitch blanking output signal at pin 20 of the AUX I/O connector.)
BPP
Selects a +5V level for the retrace and bandswitch blanking
outputs.
EP0
Selects TTL-low to turn RF on during square wave/pulse modulation.
EP1
Selects TTL-high to turn RF on during square wave/pulse
modulation.
FRS
Permits setting the frequency scaling reference multiplier value.
The multiplier value must be between 0.1 to 14 and must be
terminated with TMS.
Programming Example:
Programming “FRS 3 TMS” sets the frequency scaling reference multiplier to 3.
This command affects all entered and displayed frequencies,
but does not affect the output of the instrument.
2-41
PROGRAMMING WITH
GPIB COMMANDS
CONFIGURATION
COMMANDS
Table 2-14.
Configuration Commands (2 of 2)
MNEMONIC
CODE
2-42
FUNCTION
PPO
Selects normally-open contacts on the internal penlift relay.
(The penlift relay output, available at the rear panel PEN LIFT
OUT connector, is used to lift a plotter pen during retrace.)
PPC
Selects normally-closed contacts on the internal penlift relay.
RC0
Selects RF to be off during frequency switching in CW, step
sweep, and list sweep modes.
RC1
Selects RF to be on during frequency switching in CW, step
sweep, and list sweep modes.
RT0
Selects RF to be off during retrace.
RT1
Selects RF to be on during retrace.
RO0
Selects RF to be on at reset. (This is the default mode.)
RO1
Selects RF to be off at reset.
TR0
Sets 0 dB of attenuation when RF is switched off in units with a
step attenuator (Option 2) installed. If Option 2 is not installed,
this command produces a syntax error.
TR1
Sets 40 dB (minimum) of attenuation when RF is switched off
in units with a step attenuator (Option 2) installed. This provides better output source match. If Option 2 is not installed,
this command produces a syntax error.
681XXC PM
Changed: May 1999
PROGRAMMING WITH
GPIB COMMANDS
2-15
GROUP EXECUTE
TRIGGER COMMANDS
GROUP EXECUTE
TRIGGER COMMANDS
Table 2-15 lists the group execute trigger (GET) command mnemonic
codes. These commands let a GET bus message (Table 1-3) be used to
trigger certain signal generator functions and thus speed up bus operations.
In the default state, the 681XXC responds to a GET message by triggering a single sweep.
Table 2-15.
Group Execute Trigger Commands
MNEMONIC
CODE
GTC
Configures the 681XXC to execute an SQF command (scan to
the next higher preset CW frequency) each time a GET message is received.
GTD
Configures the 681XXC to execute a DN command (steps the
open parameter down by the step size) each time a GET message is received.
GTF
Configures the 681XXC to execute a fast-frequency-switching
step (Table 2-17) each time a GET message is received.
GTL
Configures the 681XXC to execute a TSS command (steps to
the next point in a dual step sweep mode) each time a GET
message is received.
GTO
Disables the GET functions.
GTS
Configures the 681XXC to execute a TRS command (trigger a
single sweep) each time a GET message is received. This is
the default mode.
GTT
Configures the 681XXC to execute a TST command (execute a
complete signal generator self test) each time a GET message
is received.
GTU
Configures the 681XXC to execute a UP command (steps the
open parameter up by the step size) each time a GET message
is received.
Y
681XXC PM
Changed: May 1999
FUNCTION
Sending a “Y” is equivalent to sending a GET.
2-41A/2-42A
PROGRAMMING WITH
GPIB COMMANDS
2-16
LIST SWEEP
COMMANDS
LIST SWEEP
COMMANDS
Table 2-16 lists the list sweep command mnemonic codes. These commands provide for (1) placing the signal generator in list sweep mode,
(2) accessing up to four lists of 2000 frequency/power level sets, and (3)
generating a phase-locked step sweep of the list frequency/power level
sets.
In list sweep mode, up to four lists of 2000 non-sequential frequency/
power level sets can be stored and accessed. A list index (0 thru 1999)
identifies each frequency/power level set in a list. When commanded,
the signal generator generates a phase-locked step sweep between the
specified list start index and list stop index.
Accessing
and Editing
a List
The command, LST, places the signal generator in
list sweep mode. The ELN(x) command is used to select which of the four lists is to be accessed. The first
list (list number 0) is the same list that is available
via local (front panel) control. This list is stored in
non-volatile RAM to preserve any settings after the
instrument is powered off. The other three lists (list
numbers 1, 2, and 3) are all stored in volatile RAM
and all settings are lost when power to the signal
generator is turned off. At power up, list numbers 1,
2, and 3 are set to their default state of 2000 index
entries of 5 GHz at 0 dBm.
The ELI(xxxx) command sets the list index for the
current list. Use the LF command to set the list frequencies starting at the list index and the LP command to set the list power levels starting at the list
index. Any number of frequencies and power levels
can follow these commands.
Another method of entering frequency and power
level information into the current list index is to use
the command, CTL, which copies the current CW
frequency and power level to the current list index.
Programming Example:
Programming “LST ELN1 ELI1234 LF 2 GH,
5 GH, 1 GH, 8 GH LP 2 DM, 9 DM, –3 DM,
–10 DM” places the signal generator in list sweep
mode, selects list number 1, and sets the list index
to 1234. List index 1234 is set to 2 GHz at 2 dBm,
list index 1235 is set to 5 GHz at 9 dBm, list index
1236 is set to 1 GHz at –3 dBm, and list index 1237
is set to 8 GHz at –10 dBm.
681XXC PM
Changed: May 1999
2-43
PROGRAMMING WITH
GPIB COMMANDS
LIST SWEEP
COMMANDS
Table 2-16.
List Sweep Commands
MNEMONIC
CODE
LST
ELI(xxxx)
ELN(x)
2-44
FUNCTION
Places the 681XXC in List Sweep mode.
Sets list index to xxxx, where xxxx = 4-digit integer between
0000 and 1999.
Sets list number to x, where x = 1-digit integer between 0 and
3.
LF
Sets list frequencies starting at the list index. Any number of
frequencies can follow. This command does not change the
value of the list index.
LP
Sets list power levels starting at the list index. Any number of
power levels can follow. This command does not change the
value of the list index.
LIB(xxxx)
Sets the list start index to xxxx, where xxxx = 4-digit integer
between 0000 and 1999.
LIE(xxxx)
Sets the list stop index to xxxx, where xxxx = 4-digit integer
between 0000 and 1999.
AUT
Selects Auto Trigger
HWT
Selects External Trigger
EXT
Selects Single Trigger
TRG
Triggers a Single Sweep (only in Single Trigger mode)
MNT
Selects Manual Trigger
UP
Increases list index by one (only in Manual Trigger mode)
DN
Decreases list index by one (only in Manual Trigger mode)
LEA
Learn List (This command initiates a process that examines
every index in the list and performs all calculations necessary
to set the frequency and power levels.)
CTL
Copy current CW frequency and power level to the current list
index.
681XXC PM
Changed: May 1999
PROGRAMMING WITH
GPIB COMMANDS
LIST SWEEP
COMMANDS
List Sweep
Triggering
Four different modes of triggering are available in
list sweep mode—automatic, external, single, and
manual. When automatic, external, or single trigger
mode is selected, the output sweeps between the
specified list start and stop indexes, dwelling at
each list index for the specified dwell time. When
manual trigger is selected, the list start index, list
stop index, and dwell time parameter are not used.
Instead, the list index is incremented using the UP
command or an external TTL trigger and is decremented using the DN command.
The AUT command selects automatic sweep triggering and the HWT command selects external sweep
triggering. Whe external sweep trigger mode is
selected, the output sweep recurs when triggered by
an external TTL-compatible clock pulse to the rear
panel AUX I/O connector. The EXT command selects
single list sweep triggering. When single sweep trigger mode is selected, a single list sweep starts when
the TRG command is received.
The MNT command selects the manual trigger
mode. In manual trigger mode, the list index is incremented by one each time the UP command is received or each time an external TTL trigger is
received. The list index is decremented by one each
time the DN command is received.
Generating a
List Sweep
Generating a list sweep involves selecting a sweep
range, a dwell-time-per-step, and a sweep trigger.
The list sweep range is defined by a list start index
and a list stop index. Use the LIB(xxxx) command to
set the list start index and the LIE(xxxx) command
to set the list stop index. The dwell-time-per-step of
the list sweep is changed using the LDT parameter
entry command. Select a trigger for the list sweep
using the list sweep trigger commands perviously
described.
Programming Example:
Programming “LIB1234 LIE1237 EXT LDT 10
MS EXT” implements a list sweep from current list
index 1234 to index 1237 in single trigger mode with
a 10 ms dwell-time-per-step, then triggers a single
sweep.
681XXC PM
Changed: May 1999
2-45
PROGRAMMING WITH
GPIB COMMANDS
LIST SWEEP
COMMANDS
List Calculations
During the initial list sweep, the signal generator
performs calculations to set the frequency and
power levels. This causes the initial list sweep to
take longer than each subsequent sweep. The command, LEA, initiates a process that examines every
index in the current list and performs all the calculations necessary to set the frequency and power
levels. This lets the initial list sweep be as fast as
each subsequent sweep.
The list calculations are for the current list only.
Any changes to the current list or selection of another list requires the calculations to be performed
again. The calculations are stored only in volatile
RAM and are lost when power to the signal generator is turned off.
2-46
681XXC PM
Changed: May 1999
PROGRAMMING WITH
GPIB COMMANDS
2-17
FAST-FREQUENCYSWITCHING
COMMANDS
FAST-FREQUENCYSWITCHING COMMANDS
Table 2-17 lists the fast-frequency-switching command mnemonic
codes. These commands provide for reducing the time that it takes to
switch between CW frequencies.
In the fast-frequency-switching mode, up to 3202 frequencies can be
loaded into a table. A table pointer can then be set to point to a specific
frequency in the table and the signal generator commanded to switch
from that frequency through the following frequencies to the bottom of
the table.
Loading the
Frequency
Table
To load the frequency table, use the command
ZTLbbbbnnnnD8D8D8.....D8, where “bbbb” is the table location where the frequency points are to start
loading, “nnnn” is the number of frequency points to
be loaded, and “D8” is the frequency of the frequency
point. Both “bbbb” and “nnnn” are 4 binary byte integers and “D8” is 8 binary bytes of an IEEE-754
double precision floating point number. The order of
the bytes in each field is most significant byte first.
NOTE
Use of the commands ZL(X000-999), ZEL,
and ZS(X000-999) limits the number of frequency points in the table to 1000.
Figures 2-13 thru 2-13b show an example of fast-frequency-switching
mode programming.
Table 2-17.
Fast-Frequency-Switching Commands
MNEMONIC
CODE
ZPN
Sets the table pointer (ZPNbbbb), where bbbb is the location
the pointer is to point to.
ZTL
Loads the frequency table (ZTLbbbbnnnnD8D8D8.......D8),
where bbbb is the table location where the frequency points
are to start loading, nnnn is the number of frequencies to be
loaded, and D8 is the frequency of the frequency point.
ZL(X000-999)
Loads a CW frequency into the stack at location X. The location is a number from 000 to 999.
ZEL
ZS(X000-999)
681XXC PM
FUNCTION
Ends frequency loading.
Sets the stack pointer to point to location X. The location is a
number from 000 to 999.
2-47
PROGRAMMING WITH
GPIB COMMANDS
FAST-FREQUENCYSWITCHING COMMANDS
The following is an example of fast-frequency-switching mode programming. This is a IBM-PC based program using the
National Instruments NI-488.2 C language interface library (mcib.lib) and header (decl.h).
#include <stdio.h>
#include “decl.h”
#define BOARD_ID
void main()
{
Addr4882_t
double
int
char
0
source_addr = 5,
device_addr[2] = {5, NOADDR};
freq_list[2] = {600e6, 8e9},
*double_ptr;
start_index,
num_freqs = 2,
*integer_ptr;
command_str[50];
/** Clear the bus and take control.
**/
SendIFC(BOARD_ID);
if (ibsta & ERR)
{
exit (-1);
}
/** Set the remote enable line.
**/
EnableRemote(BOARD_ID, device_addr);
if (ibsta & ERR)
{
exit (-1);
}
/** Set the start index to an arbitrary starting point.
**/
start_index = 12;
/** Begin constructing the command.
**/
command_str[0] = ‘Z’;
command_str[1] = ‘T’;
command_str[2] = ‘L’;
integer_ptr = &start_index;
command_str[3] = (char)(*(integer_ptr + 3));
command_str[4] = (char)(*(integer_ptr + 2));
command_str[5] = (char)(*(integer_ptr + 1));
command_str[6] = (char)(*integer_ptr);
/** Start with the ZTL command. **/
/**
/**
/**
/**
/**
/**
Point to the start index. **/
Get the value of the fourth byte. **/
Data is LSB first on Intel based PCs. **/
Get the value of the third byte. **/
Get the value of the second byte. **/
Get the value of the first byte. **/
NOTE: This program is continued in Figure 2-13a.
Figure 2-13.
2-48
Fast-Frequency-Switching Programming Example (1 of 3)
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
FAST-FREQUENCYSWITCHING COMMANDS
integer_ptr = &num_freqs;
command_str[7] = (char)(*(integer_ptr + 3));
command_str[8] = (char)(*(integer_ptr + 2));
command_str[9] = (char)(*(integer_ptr + 1));
command_str[10] = (char)(*integer_ptr);
/**
/**
/**
/**
/**
Point to the number of frequencies. **/
Get the value of the fourth byte. **/
Get the value of the third byte. **/
Get the value of the second byte. **/
Get the value of the first byte. **/
double_ptr = &(freq_list[0])
command_str[11] = (char)(*(double_ptr + 7));
/**
/**
/**
/**
/**
/**
/**
/**
/**
/**
Point to the first frequency. **/
Get the value of byte 7. **/
Data is LSB first on Intel based PCs. **/
Byte 6. **/
Byte 5. **/
Byte 4. **/
Byte 3. **/
Byte 2. **/
Byte 1. **/
Byte 0. **/
/**
/**
/**
/**
/**
/**
/**
/**
/**
Point to the second frequency. **/
Get the value of byte 7. **/
Byte 6. **/
Byte 5. **/
Byte 4. **/
Byte 3. **/
Byte 2. **/
Byte 1. **/
Byte 0. **/
command_str[12]
command_str[13]
command_str[14]
command_str[15]
command_str[16]
command_str[17]
command_str[18]
=
=
=
=
=
=
=
(char)(*(double_ptr +
(char)(*(double_ptr +
(char)(*(double_ptr +
(char)(*(double_ptr +
(char)(*(double_ptr +
(char)(*(double_ptr +
(char)(*double_ptr );
double_ptr = &(freq_list[1])
command_str[19] = (char)(*(double_ptr +
command_str[20] = (char)(*(double_ptr +
command_str[21] = (char)(*(double_ptr +
command_str[22] = (char)(*(double_ptr +
command_str[23] = (char)(*(double_ptr +
command_str[24] = (char)(*(double_ptr +
command_str[25] = (char)(*(double_ptr +
command_str[26] = (char)(*double_ptr );
6));
5));
4));
3));
2));
1));
7));
6));
5));
4));
3));
2));
1));
/** Send the command.
**/
Send(BOARD_ID, source_addr, command_str, 27, DABend);
if (ibsta & ERR)
{
exit (-1);
}
/** Set the pointer back to the start index.
**/
command_str[0] = ‘Z’;
command_str[1] = ‘P’;
command_str[2] = ‘N’;
/** ZPN command. **/
integer_ptr = &start_index;
command_str[3] = (char)(*(integer_ptr + 3));
command_str[4] = (char)(*(integer_ptr + 2));
command_str[5] = (char)(*(integer_ptr + 1));
command_str[6] = (char)(*integer_ptr);
/**
/**
/**
/**
/**
Point to the start index. **/
Get the value of the fourth byte. **/
Get the value of the third byte. **/
Get the value of the second byte. **/
Get the value of the first byte. **/
/** Send the command.
**/
Send(BOARD_ID, source_addr, command_str, 7, DABend);
if (ibsta & ERR)
{
exit (-1);
}
NOTE: This program is continued in Figure 2-13b.
Figure 2-13a.
681XXC PM
Fast-Frequency-Switching Programming Example (2 of 3)
2-49
PROGRAMMING WITH
GPIB COMMANDS
FAST-FREQUENCYSWITCHING COMMANDS
/** Send a trigger.
**/
Trigger(BOARD_ID, source_addr);
if (ibsta & ERR)
{
exit (-1);
}
/** Source is now outputting 600 MHz. **/
/** Send a trigger.
**/
Trigger(BOARD_ID, source_addr);
if (ibsta & ERR)
{
exit (-1);
}
/** Source is now outputting 8 GHz. **/
exit(0);
} /** End of main **/
Figure 2-13b.
2-50
Fast-Frequency-Switching Programming Example (3 of 3)
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
2-18
POWER-OFFSETTABLE COMMANDS
POWER-OFFSETTABLE COMMANDS
Table 2-18 list the power-offset-table command mnemonic codes. These
commands provide for maintaining a consistent power level at a point
within a test setup across the measurement frequencies. This “flattening” of the test point power level is accomplished by summing a power
offset word (from the power offset table) with the Signal Generator’s
normal power level DAC word at each frequency point.
The power-offset mode works in conjunction with the fast-frequencyswitching mode (para. 2-17). The frequency stack must be loaded before loading the power-offset table because the frequency loading sets
the upper limit for the number of entries in the power-offset table. The
same pointer is used for both the frequency stack and the power-offset
table. Once the power-offset table is loaded, the PT1 command turns
on the power-offset mode; the PT0 command turns it off.
Loading the
Power-Offset
Table
To load the power-offset table, use the command,
PTL clch dldh....., where “clch” is the number of
power-offset words and “dldh” is a power-offset word.
Both “clch” and “dldh” are two-byte binary words
sent LOW byte first and HIGH byte second. The
power-offset word is in hundreths of a dB. Negative
power offsets use twos-complement representation.
To change a power-offset word in the table, use the
PTC dldh command, where “dldh” is the new poweroffset word for the current power level setting.
Programming Note:
Care must be taken to send the exact number of
power-offset words specified in the wordcount,
“clch”. If to few words are sent, the GPIB interface
may not respond properly.
Figures 2-14 and 2-14a show an example of power-offset mode programming.
Table 2-18.
Power-Offset-Table Command
MNEMONIC
CODE
681XXC PM
FUNCTION
PT0
Disable the Power Offset Table
PT1
Enable the Power Offset Table
PTC
Change a Power Offset Table entry (PTC dldh), where dldh is
the new offset word for the current table entry.
PTL
Load a Power Offset Table (PTL clch dldh ...), where clch is the
data word count and dldh is the data word.
2-51
PROGRAMMING WITH
GPIB COMMANDS
POWER-OFFSETTABLE COMMANDS
The following is an example of power-offset mode programming. This program is written for use with an IBM-PC type computer/controller containing an IOtech GPIB interface.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/* IOtech Driver488/LIB Subroutine Interface definitions... */
#include “\ieee488\iotlib.h”
#include “\ieee488\iot_main.h”
/* Define the device handles */
DevHandleT Synth,ieee;
void main()
{
char CmdString[10], DataString[40], String[40];
unsigned char XString[160];
int
next_step,i,j;
/*************************************************************************/
/* Initialize the IOtech interface board and */
/* obtain the interface’s handle.
*/
#define
ADDRESS 5
if((ieee=InitIeee488(btMP488CT, 21, -1, 0x02el, 7, 5, 1, 10000,0))==-1)
{
printf(“Cannot initialize IEEE 488 system.\n”)
exit(1);
}
if(( Synth=CreateDevice( ADDRESS, -1 ) )==-1)
{
printf(“Cannot create Synth device.\n”);
exit(1);
/* Set the device timeout so you don’t wait forever if there’s a problem */
TimeOut(Synth, 2000);
/* Handle the errors in the program */
Error(Synth,OFF);
/*************************************************************************/
/* Address the Synthesizer to listen */
NOTE: This program is continued in Figure 2-14a.
Figure 2-14.
2-52
Power-Offset Mode Programming Example (1 of 2)
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
POWER-OFFSETTABLE COMMANDS
strcpy(XString,"_?U%");
SendCmd(Synth,XString,strlen(XString));
Output(Synth,"RST");
Output(Synth,"GTF");
Output(Synth,"ZL000");
Output(Synth,"1 GH 2 GH 3 GH 4 GH 5 GH 6 GH 7 GH 8 GH 9 GH 10 GH");
Output(Synth,"ZEL");
/* Make a data array with the PTL command, the word count */
/* and the binary data in low-byte, high-byte order.
*/
DataString[0]=’P’;
DataString[1]=’T’;
DataString[2]=’L’;
DataString[3]=10;
/* Low byte — ten words */
DataString[4]=0;
/* High byte —
*/
DataString[5]=0;
/* 0 */
DataString[6]=0;
DataString[7]=20;
/* 276 */
DataString[8]=1;
DataString[9]=30;
/* 542 */
DataString[10]=2;
DataString[11]=40;
/* 808 */
DataString[12]=3;
DataString[13]=50;
/* 1074 */
DataString[14]=4;
DataString[15]=60;
/* 1340 */
DataString[16]=5;
DataString[17]=70;
/* 1606 */
DataString[18]=6;
DataString[19]=80;
/* 1872 */
DataString[20]=7;
DataString[21]=90;
/* 2138 */
DataString[22]=8;
DataString[23]=100;
/* 2404 */
DataString[24]=9;
/* Send the data with an EOI on the last byte */
SendEoi(Synth,DataString,25);
Output(Synth,"PT1");
Output(Synth,"ZS000");
for(next_step=0;next_step<10;next_step++)
{
Output(Synth,"Y");
printf(“Press Enter for Next Frequency”);
getchar();
}
} /* End of main() */
Figure 2-14a.
681XXC PM
Power-Offset Mode Programming Example (2 of 2)
2-53
PROGRAMMING WITH
GPIB COMMANDS
2-19
USER LEVEL
CALIBRATION
COMMANDS
USER LEVEL
CALIBRATION COMMANDS
Table 2-19 lists the user level calibration commands. These commands
provide for (1) activating individual user level calibration tables, (2)
sending the tables to the controller, and (3) recalling the tables from
the controller.
The user level (flatness correction) calibration function provides for
calibrating out path variations in a test setup. This is accomplished by
means of an entered power-offset table from a GPIB power meter or
calculated data. When the user level calibration table is activated, the
set power level is delivered to the point in the test setup where the
calibration was performed. Up to five user level calibration tables from
2 to 801 frequency points/table can be created and stored in 681XXC
memory for recall. (Refer to the 681XXC Operation Manual, chapter 3,
for user level calibration procedures.)
The commands, LU1 thru LU5, each activate an individual user level
calibration table (#1 thru #5). The LU0 command turns off the active
user level calibration table. The LUS command sends all five tables of
user level calibration data to the controller where they are stored in a
binary data file. While stored in the file, the data can be edited (see
page 2-58). The LUR command readies the 681XXC to receive the five
tables of user level calibration data from the controller. Figures 2-15
thru 2-15b show an example program for saving and recalling user
level calibration tables.
Table 2-19.
User Level Calibration Commands
MNEMONIC
CODE
2-54
FUNCTION
LU0
Turns off the active user level calibration table.
LU1
Activates user level calibration table #1.
Turns off any other active user level calibration table.
LU2
Activates user level calibration table #2.
Turns off any other active user level calibration table.
LU3
Activates user level calibration table #3.
Turns off any other active user level calibration table.
LU4
Activates user level calibration table #4.
Turns off any other active user level calibration table.
LU5
Activates user level calibration table #5.
Turns off any other active user level calibration table.
LUR
Readies the 681XXC to receive five tables of user level
calibration data from the controller.
LUS
Sends all five tables of user level calibration data to the
controller.
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
USER LEVEL
CALIBRATION COMMANDS
The following is an example program for saving and recalling user level calibration tables. This program uses the National Instruments NI-288.2 C language interface library (mcib.lib) and header (decl.h).
#include <stdio.h>
#include “decl.h”
void gpiberr(char *);
#define
#define
#define
#define
BOARD_ID
0
USER_LVL_SAVE
USER_LVL_RECALL
USER_LVL_NUM_BYTES
1
2
8232
void main()
{
Addr4882_t
source_addr = 5
device_addr[2] = {5, NOADDR};
unsigned char user_lvl_tables[USER_LVL_NUM_BYTES];
init
user_lvl_received,
user_input;
FILE
*fp_user_lvl_data:
/** Clear the bus and take control.
**/
SendIFC(BOARD_ID);
if(ibsta & ERR)
gpiberr(“SendIFC error”);
/** Set the remote enable line.
**/
EnableRemote(BOARD_ID, device_addr);
if(ibsta & ERR)
gpiberr(“EnableRemote error”);
/** Prompt the user to save or recall the data.
**/
printf(“1. Save the data from the source\n”);
printf(“2. Recall the data to the source\n”);
printf(“Option: ”);
scanf(“%d”,&user_input);
if(user_input == USER_LVL_SAVE)
{
NOTE: This program is continued in Figure 2-15a.
Figure 2-15.
Programming Example of Saving and Recalling User Level Calibration Tables (1 of 3)
681XXC PM
2-55
PROGRAMMING WITH
GPIB COMMANDS
USER LEVEL
CALIBRATION COMMANDS
/** The LUS command tells the source to send the user level
** table data over the bus.
**/
Send(BOARD_ID, source_addr, “LUS\r\n”, 5L, DABend);
if(ibsta & ERR)
gpiberr(“Send error”);
/** Receive the user level table data.
**/
printf(“Receiving data from the source\n”);
Receive(BOARD_ID, source_addr, user_lvl_tables,
(long)USER_LVL_NUM_BYTES, STOPend);
if(ibsta & ERR)
gpiberr(“Receive error”);
user_lvl_received = ibcntl;
printf(“Received %d bytes of user level data\n”,
user_lvl_received);
else
/** Open binary data file and output the data.
**/
if((fp_user_lvl_data = fopen(“userlvl.dat”,"w+b")) == NULL)
{
printf(“Can’t open the userlvl.dat data file\n”);
}
else
{
printf(“Outputting to userlvl.dat in the current
directory\n”);
fwrite(user_lvl_tables, sizeof(user_lvl_tables[0]),
USER_LVL_NUM_BYTES, fp_user_lvl_data);
}
}
{
/** Open the binary data file and read the data.
**/
if((fp_user_lvl_data = fopen(“userlvl.dat”,"rb")) == NULL)
{
printf(“Can’t open the userlvl.dat data file\n”);
}
else
{
printf(“Inputting from userlvl.dat in the current
directory\n”);
fread(user_lvl_tables, sizeof(user_lvl_tables[0]),
USER_LVL_NUM_BYTES, fp_user_lvl_data);
}
NOTE: This program is continued in Figure 2-15b.
Figure 2-15a.
2-56
Programming Example of Saving and Recalling User Level Calibration Tables (2 of 3)
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
USER LEVEL
CALIBRATION COMMANDS
/** The LUR command readies the source to receive the user
** level table data. Notice that there is no carriage
** return, line feed, or EOI sent with the LUR command.
**/
Send(BOARD_ID, source_addr, “LUR”, 3L, NULLend);
if(ibsta & ERR)
gpiberr(“Send error; LUR”);
/** The data is sent to the source immediately following the
** LUR command.
**/
printf(“Sending %d bytes of data to the source\n”,
USER_LVL_NUM_BYTES);
Send(BOARD_ID, source_addr, user_lvl_tables,
(long)USER_LVL_NUM_BYTES, DABend);
if(ibsta & ERR)
gpiberr(“Send error; data”);
}
fclose(fp_user_lvl_data);
exit(0);
}/** end of main **/
/****************************************************************************************
***Name: gpiberr
**Desc: Display error code and message for all GPIB operation
**Receives: errsta - the error string to display
**Returns: nothing
**/
void gpiberr(char *errstr)
{
printf(“\n%s\nError code = %d\n”,errstr,iberr);
}/** end of gpiberr **/
Figure 2-15b.
681XXC PM
Programming Example of Saving and Recalling User Level Calibration Tables (3 of 3)
2-57
PROGRAMMING WITH
GPIB COMMANDS
USER LEVEL
CALIBRATION COMMANDS
Editing the
Table Data
While stored in the binary data file of the controller,
the data of the five user level calibration tables can
be edited. An editor that can display the data file in
hexadecimal will be needed to perform the edit.
Types of Data Storage Methods
There are three types of data storage methods used
for user level calibration data. Each is described in
the following paragraphs. (The data item descriptions will refer back to these data types.)
Double:
8 bytes. Most significant byte first.
ANSI/IEEE-754 64-bit floating point format.
|S|
E
|
F
|
where:
S (1 bit) = sign bit, 0 positive, 1 negative
E (11 bits) = exponent, biased by 1023 base 10
F (52 bits) = fraction, 0 £F <1
value = [(–1) raised to the S power] ´
[2 raised to the (E – 1023) power] ´
[1 + F]
Example:
801 is stored as 40 89 08 00 00 00 00 00, base 16.
S=0
E = 408 base 16 = 1032 base 10
F = .908 base 16 = .564453125 base 10
801 = 1 ´ 512 ´ 1.564453125
Integer:
4 bytes. Most significant byte first.
Stored as a signed integer. The sign bit is the most
significant bit. Negative numbers are stored in 2’s
complement form.
Example:
7025 is stored as 00 00 1B 71, base 16.
–7025 is stored as FF FF D4 8F, base 16 2’s com
plement.
Short:
2 bytes. Most significant byte first.
Stored as a signed short. The sign bit is the most
significant bit. Negative numbers are stored in 2’s
complement form.
Example:
350 is stored as 01 5E, base 16.
–350 is stored as FE A2, base 16.
2-58
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
USER LEVEL
CALIBRATION COMMANDS
Data Item Descriptions
Each data item contained in the binary data file is
described below with the following information:
q
q
q
q
q
Data name
Description
Type of data storage
Offset into the data file for each user level
calibration table
Data units
Figure 2-16 (page 2-61) shows a printout of a section
of the data file that contains each of these data
items for user level calibration table #2.
Name: Start Frequency
Description: The starting frequency for each user
level calibration.
Type: Double
Offsets (base 16): Table #1 0006
Table #2 0674
Table #3 0CE2
Table #4 1350
Table #5 19BE
Units: mHz (millihertz)
Name: Stop Frequency
Description: The ending frequency for each user
level calibration.
Type: Double
Offsets (base 16): Table #1 000E
Table #2 067C
Table #3 0CEA
Table #4 1358
Table #5 19C6
Units: mHz (millihertz)
Name: Frequency Increment
Description: The frequency increment for 1 point.
This value = (stop frequency – start frequency) divided by the number of points.
Type: Double
Offset (base 16): Table #1 0016
Table #2 0684
Table #3 0CF2
Table #4 1360
Table #5 19CE
Units: mHz (millihertz)
681XXC PM
2-59
PROGRAMMING WITH
GPIB COMMANDS
USER LEVEL
CALIBRATION COMMANDS
Name: Number of Points
Description: The number of frequency points.
Type: Double
Offsets (base 16): Table #1 001E
Table #2 068C
Table #3 0CFA
Table #4 1368
Table #5 19D6
Units: a value of 1 = 1 point
Name: Level Correction Offset
Description: This is the power level that is added
to the front panel power before the level correction
point table power levels are subtracted. It represents the maximum power deviations read during
the calibration.
Type: Integer
Offsets (base 16): Table #1 0026
Table #2 0694
Table #3 0D02
Table #4 1370
Table #5 19DE
Units: mdB (milli-dB)
Name: Level Correction Point Table
Description: These are the power level correction
values with respect to the maximum power deviation read during the calibration.
Type: Short (Array of 801 Points)
Offsets (base 16): Table #1 002A
Table #2 0698
Table #3 0D06
Table #4 1374
Table #5 19E2
Units: mdB (milli-dB)
2-60
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
USER LEVEL
CALIBRATION COMMANDS
000640
000650
000660
000670
000680
000690
0006A0
0006B0
0006C0
0006D0
00
00
00
00
E5
00
FF
00
00
00
00
00
00
00
40
00
93
00
00
00
00
00
00
DA
00
00
FF
00
00
00
00
00
00
BE
00
00
9C
00
00
00
00
00
00
42
42
00
FF
00
00
00
00
00
00
7D
6D
00
F6
00
00
00
00
00
00
1A
1A
17
00
00
00
00
00
00
00
94
94
83
00
00
00
00
00
00
00
A2
A2
FF
FF
00
00
00
00
00
00
00
00
11
C4
00
00
00
00
00
00
00
00
FF
D1
00
00
00
00
00
00
00
00
56
21
00
00
00
00
00
00
42
40
FF
E8
00
00
00
00
00
00
A2
22
56
37
00
00
00
00
00
BA
30
00
FF
00
00
00
00
00
00
BE
9C
00
74
00
00
00
00
Printout Explanation
The printout shows a section of the user level calibration data file, in hexadecimal, that contains each of the data items for user level calibration table #2. The offset into the data file is
shown at the left in the printout.
Offset 0674: Start Frequency
42 7D 1A 94 A2 00 00 00 = 2 GHz
Offset 067C: Stop Frequency
42 A2 30 9C E5 40 00 00 = 10 GHz
Offset 0684: Frequency Increment
42 6D 1A 94 A2 00 00 00 = 1 GHz
Offset 068C: Number of Points
40 22 00 00 00 00 00 00 = 9 points
Offset 0694: Level Correction Offset
00 00 17 83 = 6.016 dB
Offset 0698: Level Correction Point Table (9 points)
FF 11 = –.239 dB
FF 56 = –.170 dB
FF 56 = –.170 dB
FF 74 = –.140 dB
FF 93 = –.109 dB
FF 9C = –.100 dB
FF F6 = –.010 dB
00 00 = 0 dB
FF C4 = –.060 dB
Figure 2-16.
681XXC PM
Printout of a Section of the User Level Calibration Binary Data File
2-61
PROGRAMMING WITH
GPIB COMMANDS
2-20
MASTER-SLAVE
OPERATION
COMMANDS
MASTER-SLAVE
OPERATION
Table 2-20 lists the master-slave operation command mnemonic codes.
These commands provide for enabling two instruments (68XXXB
and/or 68XXXC) that are connected in a master-slave configuration to
produce CW and synchronized, swept output signals at a frequency
offset.
In a master-slave configuration, one instrument (the Master) controls
the other (the Slave) via interface cables between their rear panel AUX
I/O and SERIAL I/O connectors. The two units are phase-locked together by connecting them to the same 10 MHz reference time base.
(Refer to the 681XXC Operation Manual, Chapter 7—Use With Other
Instruments, for master-slave interconnection and operating instructions.)
The parameter entry commands, SLF0 - SLF9 and SLM0 - SLM9, are
used to set the F0 - F9 and M0 - M9 frequencies for the Slave unit; the
SLDF command is used to set the DF parameter for the Slave unit. The
main output power level (L1) for the Slave unit is set using the SLV or
SLL1 command; the alternate sweep power level (L2) for the Slave
unit is set using the SLL2 command. The S1 command turns on the
master-slave mode of operation; the S0 command turns off the masterslave mode of operation.
Programming Example:
Programming “SLF1 5 GH SLF2 8 GH SLL1 3 DM S1” sets the
Slave unit F1 frequency to 5 GHz, its F2 frequency to 8 GHz, and its
output power level to 3 dBm and turns on the master-slave mode of
operation. Now, when the Master unit is programmed to perform a F1
to F2 sweep, the Slave unit will produce a synchronous 5 GHz to
8 GHz frequency sweep that has an output power level of 3 dBm.
Programming Note:
Use the SOF command only to set the frequency offset for a Slave unit
that is (1) slave to a Master unit that is connected to a 360B VNA in a
source or dual-source configuration or (2) slave to a Master unit that is
programmed to perform non-sequential frequency step sweeps (refer to
Special Step Sweep on page 2-20).
Table 2-20.
Master-Slave Operation Commands
MNEMONIC
CODE
2-62
FUNCTION
S0
Turns off the Master-Slave mode of operation.
S1
Turns on the Master-Slave mode of operation.
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
2-21
SELF TEST COMMAND
SELF TEST
COMMAND
Table 2-21 lists the self test command mnemonic code. This command
provides for executing a signal generator self test.
When a TST command is received, the signal generator performs a self
test, then places a “P” (for pass) or a “F” (for fail) on the bus. It also
generates six self test results bytes. Figure 2-18 (next page) shows the
six self test results bytes and identifies the reporting function of each
bit.
When self test is completed, bit 7 of Self Test Results Byte 6 and bit 2
of Extended Status Byte 1 are both set. If a failure(s) occurs during
self test, the Self Test Results Byte bit(s) reporting the failure(s) and
bit 0 of Extended Status Byte 1 are set.
The OSR command returns the six self test results bytes to the controller. Figure 2-17 provides an example of self test command programming.
Programming Note: The “P or “F” character placed on the bus by the
signal generator self test must be cleared from the output buffer (read
by the controller) before another output command, such as OSR, is
sent. If it is not cleared, the first character of the next output will be
missing. Line 30 (Figure 2-17) shows clearing of the “P” or “F” character.
Table 2-21.
Self Test Command
MNEMONIC
CODE
TST
Executes a signal generator self test. Extended Status Byte 1
bit 0 is set if self test fails; bit 2 is set when self test is complete.
10
20
30
40
50
60
70
80
Figure 2-17.
681XXC PM
FUNCTION
OUTPUT 705; “CSB”
OUTPUT 705; “TST”
ENTER 705; D$
DISP D$
OUTPUT 705; “OSR”
ENTER 705 USING “#,B”; A, B, C, D, E, F
DISP A; B; C; D; E; F
END
Self Test Command Programming Example
2-63
PROGRAMMING WITH
GPIB COMMANDS
SELF TEST
COMMANDS
Self Test Results Byte 1
Sweep Time
Circuitry Failed
A18 Power
Supply is Not
Locked
Power Supply
Voltage(s) are
Out of Reg
A12 –10 Volt
Reference
Check Failed
A12 +10 Volt
Reference
Check Failed
DVM –10 Volt
Reference
Check Failed
DVM +10 Volt
Reference
Check Failed
DVM Ground
Offset Check
Failed
Bit 7
(128)
Bit 6
(64)
Bit 5
(32)
Bit 4
(16)
Bit 3
(8)
Bit 2
(4)
Bit 1
(2)
Bit 0
(1)
Self Test Results Byte 2
Not Locked
Indicator
Check Failed
Down Converter
is
Not Locked
YIG Loop
Circuitry is
Not Locked
Coarse Loop
Circuitry is
Not Locked
Fine Loop
Circuitry is
Not Locked
High Stability
Crystal is
Not Locked
Ext 10 MHz
is
Not Locked
Oven
is
Not Ready
Bit 7
(128)
Bit 6
(64)
Bit 5
(32)
Bit 4
(16)
Bit 3
(8)
Bit 2
(4)
Bit 1
(2)
Bit 0
(1)
Delta-F Ramp
Circuitry
Failed
Center
Frequency
Circuitry Failed
Marker Switch
Point
Circuitry Failed
Linearizer
Circuitry
Failed
FM Loop
Gain
Circuitry Failed
Bit 5
(32)
Bit 4
(16)
Bit 3
(8)
Bit 2
(4)
Bit 1
(2)
Bit 0
(1)
Self Test Results Byte 3
Detector Log
Amp Circuitry
Failed
Bit 7
(128)
Level Reference
Not Leveled
Circuitry
Detector
Failed
Circuitry Failed
Bit 6
(64)
Self Test Results Byte 4
3.3 - 5.5 GHz
Switch Filter
Section or
Level Detector
Circuitry Failed
2-3.3 GHz
Switch Filter
Section or
Level Detector
Circuitry Failed
Switch Filter
or
Level Detector
Circuitry Failed
0.01 - 2 GHz
Range
Unleveled
A10 Q5 or
Associated
Circuitry Failed
2 - 8.4 GHz
Range
Unleveled and
Not Locked
8.4 - 20 GHz
Range
Unleveled and
Not Locked
2 - 20 GHz
Range
Unleveled and
Not Locked
Bit 7
(128)
Bit 6
(64)
Bit 5
(32)
Bit 4
(16)
Bit 3
(8)
Bit 2
(4)
Bit 1
(2)
Bit 0
(1)
Not Used
Source
Quadrupler
Module
or Driver
Circuitry Failed
Modulator or
Driver Circuitry
on A9-1 Failed
Bit 5
(32)
Bit 4
(16)
Bit 3
(8)
Bit 2
(4)
Self Test Results Byte 5
32 - 40 GHz
Switched
Section of
Doubler Module
Switched
or Driver
Doubler Module Circuitry Failed
Failed
Bit 7
(128)
Bit 6
(64)
13.25 - 20 GHz 8.4 - 13.25 GHz 5.5 - 8.4 GHz
Switch Filter
Switch Filter
Switch Filter
Section or
Section or
Section or
Level Detector Level Detector Level Detector
Circuitry Failed Circuitry Failed Circuitry Failed
Bit 1
(2)
Bit 0
(1)
Self Test Results Byte 6
Self Test
is
Complete
Not Used
Not Used
RF Was Off
When Self Test
Started
Slope DAC or
Associated
Circuitry Failed
Sample and
Hold Circuitry
Failed
Bit 7
(128)
Bit 6
(64)
Bit 5
(32)
Bit 4
(16)
Bit 3
(8)
Bit 2
(4)
Figure 2-18.
2-64
20 - 25 GHz
25 - 32 GHz
Section of
Section of
Switched
Switched
Doubler Module Doubler Module
Failed
Failed
Bit 1
(2)
Bit 0
(1)
Self Test Results Bytes
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
2-22
MISCELLANEOUS
COMMANDS
MISCELLANEOUS
COMMANDS
Table 2-22 is a list of miscellaneous command mnemonic codes that do
not fit into any of the other classifications. These commands provide
the following operations:
q
q
q
q
q
q
GPIB Address Change
CW Ramp
Secure Mode
Returning the 681XXC to local control
Instrument Reset
Serial Number Entry
Table 2-22.
Miscellaneous Commands
MNEMONIC
CODE
FUNCTION
ADD
Permits changing of the instrument GPIB address. The
address must be between 1 and 30 and must be terminated
with ADR.
Programming Example:
Programming “ADD 13 ADR” changes the 681XXC’s address
to 13.
CS0
Turns off the CW ramp.
CS1
Turns on the CW ramp. This produces a repetitive 0V to 10V
ramp output to the rear panel HORIZ OUT connector and to
pin 1 of the AUX I/O connector.
DS0
Turns on the secure mode. This blanks the front panel display
of all frequency, power level, and modulation parameters.
DS1
Turns off the secure mode and restores the front panel display
of all frequency, power level, and modulation parameters.
RL
RST
Returns the 681XXC to local (front panel) control.
Resets the 681XXC to its default settings.
NOTE
Sending this command clears the current instrument
setup. If this setup is needed for future testing, save it
as a stored setup (para. 2 -21) before sending RST.
SNR
681XXC PM
Permits entry of the instrument serial number (SNRnnnnnnX).
The serial number, represented by nnnnnn, must be six characters in length.
2-65
PROGRAMMING WITH
GPIB COMMANDS
2-23
PROGRAM ERRORS
PROGRAM
ERRORS
Two types of errors can occur in bus programming—invalid-parameter
and syntax. These two error types are described in the following paragraphs.
InvalidParameter
Invalid-parameter errors are those that cause the
Signal Generator to beep. These errors include:
q
q
q
Syntax
Programming an analog frequency sweep
where the sweep start frequency is greater
than the stop frequency.
Attempting to enter a frequency, time, or
power level parameter that exceeds the limits
of the signal generator.
Failing to properly end a parameter entry with
a suitable terminator such as MH, DB, MS,
etc.
Syntax errors are those that occur in the formulation of a program statement, such as writing
"EXTTFS” instead of “EXTTRS”.
To prevent misinterpretation of command statements, the signal generator ignores all portions of
the command statement following the syntax error.
All commands are ignored until the signal generator
receives the Unlisten command (ASCII 63; “?” character) over the bus or until the signal generator is
addressed to talk.
2-66
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
2-24
RESET PROGRAMMING AND DEFAULT
CONDITIONS
RESET PROGRAMMING
AND DEFAULT CONDITIONS
Table 2-23 describes the five methods that can be used to reset the signal generator. They provide a means for quickly returning the 681XXC
to its default (preprogrammed) operational state.
The default settings for the numeric frequency, sweep time, and power
level parameters are the same as those listed in Table 3-1 on page 3-14
of the Series 681XXC Operation Manual (P/N 10370-10333).
Figure 2-19 (page 2-68) provides an example of a recommended sequence for programming a reset command. Using this command sequence ensures that all parameters and commands assume their preprogrammed state each time reset is desired.
Table 2-23.
Resetting the 681XXC GPIB Interface Circuits
Methods of Resetting
GPIB Interface Circuits
681XXC PM
Functions
Affected
Default
Conditions
1. Pressing the front panel
menu RETURN TO LOCAL
soft-key.
Bus Messages
Local
2. Pressing the front panel
System menu RESET
soft-key.
Service Request Modes
ES0, FB0, PE0, SB0,
SE0, SQ0, UL0, SB0
GTS
Local and Local Lockout
3. Sending the RST command over the bus.
Same as 2 above
Same as 2 above except
that the local bus message is not reset.
4. Executing the interface
message Device Clear.
Same as 2 above.
Same as 2 above except
that the local bus message is not reset.
5. Turning power on and
off.
Same as 2 above.
Places the GPIB into the
power-on state. Instrument state does not
change.
2-67
PROGRAMMING WITH
GPIB COMMANDS
PROGRAMMING
EXAMPLES
Sample Coding In Basic
10 CLEAR 705
20 OUTPUT 705; “FUL IL1 L1 10DM”
Explanation of Code
Line 10 sends the Device Clear bus message.This message clears the signal generator GPIB interface.
Line 20 sends new front panel settings: Full Sweep, Internal Leveling, and Output
Power Level of 10 dBm.
Figure 2-19.
2-25
2-68
PROGRAMMING
EXAMPLES
Reset Programming Example
Figures 2-20 thru 2-22, on the following pages, provide three examples
of GPIB programming using 681XXC command codes.
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
PROGRAMMING
EXAMPLES
The following subroutine uses the output identify (OI) command to identify the signal
generator’s model number, serial number, minimum and maximum frequencies,
minimum and maximum power level, and software revision level. This subroutine is
used in the example programs in Figures 2-21 and 2-22 to read the limits of the signal generator.
10
20
30
100
110
120
130
140
150
160
170
180
190
200
210
220
230
240
250
260
270
280
290
300
!
“GET OI”
! Gets the output id string
! from a 68XXXX Synthesizer
OUTPUT 705; “OI”
DIM A$[36]
ENTER 705; A$
M$=A$[1,2] ! Model
M1$=A$[3,4] ! Model Number
F1$=A$[5,9] ! Freq Low
F2$=A$[10,14] ! Freq High
L2$=A$[15,20] ! Min Power
L1$=A$[21,24] ! Max Power
S$=A$[25,28] ! Software Ver
S1$=A$[29,34] ! Serial Number
P$=A$[35,35] ! Model Prefix
S2$=A$[36] ! Series
PRINT “Model Number :”;M$;S2$;M1$;P$
PRINT “Serial Number :”;S1$
PRINT “Low Freq :”;F1$
PRINT “High Freq :”;F2$
PRINT “Max Power :”;L1$
PRINT “Min Power :”;L2$
PRINT “Software Ver :”;S$
END
Program Explanation
Line 100: Sends the “OI” command.
Line 110: Dimensions the variable.
Line 120: Gets the “OI” string.
Line 130: Sets M$ to the model (68).
Line 140: Sets M1$ to the model number.
Line 150: Sets F1$ to the signal generator low-end frequency.
Line 160: Sets F2$ to the signal generator high-end frequency.
Line 170: Sets L2$ to the minimum power point.
Line 180: Sets L1$ to the maximum power point.
Line 190: Sets S$ to the software version number.
Line 200: Sets S1$ to the serial number.
Line 210: Sets P$ to the model prefix number (1 or 2).
Line 220: Sets S2$ to the model series (A or B).
Lines 230-290: Prints the data obtained.
Figure 2-20.
681XXC PM
Using the Output Identify (OI) Command
2-69
PROGRAMMING WITH
GPIB COMMANDS
PROGRAMMING
EXAMPLES
The following program (1) receives entries from the keyboard to set intial frequency
and step-size parameters, and (2) activates the soft keys on the controller so that
they can step the frequency up or down.
Program Explanation
Line 30: Sets the address of the signal generator.
Line 40: Calls the device identification
subroutine described in Line 1010.
Line 50: Turns off the key definitions.
Lines 60-110: Accept the starting frequency entry and checks its validity.
Lines 120-170: Accept the step size
entry and checks its validity.
Line 180: Sets the signal generator to
the starting frequency and step size.
Lines 190-240: Set up keys and key
labels.
Line 250: Waits for a key to be
pressed.
Line 300: Reports that the STEP UP
key was pressed; sends the UP command.
Line 310: Waits for the next key.
Line 320: Reports that the STEP
DOWN key was pressed; send the
DN command.
Line 330: Waits for the next key.
Line 340: Ends the main program.
Lines 1010-1120: Identify the signal
generator address, model, frequency
range, and power range.
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
190
200
210
220
230
240
250
300
310
320
330
340
1010
1020
1030
1040
1050
1060
1070
1080
1090
1100
1110
1120
1130
! PARAMETER ENTRY, SYZ, UP, AND DN COMMANDS
Address=705
CALL Iddev(Address,Model,Fmin,Fmax,Pmin,Pmax)
OFF KEY
DISP “ENTER FREQUENCY IN GHz”;
INPUT Freq
IF Freq>Fmax OR Freq<Fmin THEN
DISP “FREQUENCY OUT OF RANGE - ”;
GOTO 60
END IF
DISP “ENTER STEP SIZE IN GHz”;
INPUT Stepsize
IF Stepsize>Fmax-Fmin OR Stepsize<.000001 THEN
DISP “ILLEGAL STEP SIZE - ”;
GOTO 120
END IF
OUTPUT Address;"CF1";Freq;"GH SYZ";Stepsize;"GH"
ON KEY 0 LABEL “STEP” GOTO 300
ON KEY 5 LABEL “ UP ” GOTO 300
ON KEY 1 LABEL “STEP” GOTO 320
ON KEY 6 LABEL “DOWN” GOTO 320
ON KEY 2 LABEL “NEW ” GOTO 50
ON KEY 7 LABEL “FREQ” GOTO 50
GOTO 250
OUTPUT Address;"UP"
GOTO 250
OUTPUT Address;"DN"
GOTO 250
END
SUB Iddev(Address,Model,Fmin,Fmax,Pmin,Pmax)
DIM Ident$[36]
OUTPUT Address;"OI"
ENTER Address;Ident$
Model=VAL(Ident$[1,2])
Model Number=VAL(Ident$[3,4])
Fmin=VAL(Ident$[5,9])
Fmax=VAL(Ident$[10,14])
Pmin=VAL(Ident$[15,20])
Pmax=VAL(Ident$[21,24])
Model Prefix=Ident$[35,35]
Series=VAL(Ident$[36])
SUBEND
Figure 2-21.
2-70
Controlling CW Frequency/Parameter Entries
681XXC PM
PROGRAMMING WITH
GPIB COMMANDS
PROGRAMMING
EXAMPLES
The following program accepts user inputs for (1) power sweep starting and ending
levels, (2) number of steps in the sweep, and (3) sweep dwell times. After accepting
such imputs, the program then commands the signal generator to obtain a display
of the power sweep.
NOTE: The signal generator should be connected to a scalar network analyzer.
Program Explanation
Line 30: Set the address of the signal
generator.
Line 40: Call the device identification
subroutine described in line 1010.
Lines 60-110: Accept the starting
power level entry and checks its validity.
Lines 120-170: Accept the ending
power level entry and checks its validity.
Lines 180-230: Accept the power
sweep number-of-steps entry and
checks it validity.
Lines 240-290: Accept the power
sweep dwell time entry and checks its
validity.
Lines 300-310: Sets the signal generator to perform the above defined
power sweep.
Line 340: Ends the main program.
Lines 1010-1120: Identify the signal
generator address, model, frequency
range, and power range.
30
40
60
70
80
90
100
110
120
130
140
150
160
170
180
190
200
210
220
230
240
250
260
270
280
290
300
310
340
1010
1020
1030
1040
1050
1060
1070
1080
1090
1100
1110
1120
1130
Address=705
CALL Iddev(Address,Model,Fmin,Fmax,Pmin,Pmax)
DISP “ENTER POWER SWEEP STARTING LEVEL (dBm)”;
INPUT Powerstart
IF Powerstart>Pmax OR Powerstart<Pmin THEN
DISP “POWER OUT OF RANGE - ”;
GOTO 60
ENDIF
DISP “ENTER POWER SWEEP ENDING LEVEL (dBm)”;
INPUT Powerstop
IF Powerstop>Pmax OR Powerstop<Pmin THEN
DISP “POWER OUT OF RANGE - ”;
GOTO 120
END IF
DISP “ENTER NUMBER OF STEPS”;
INPUT Noofsteps
IF Noofsteps<1 OR Noofsteps>10000 THEN
DISP “NUMBER OF STEPS OUT OF RANGE - ”;
GOTO 180
END IF
DISP “ENTER DWELL TIME AT EACH STEP (mS)”;
INPUT Dwell
IF Dwell<1 OR Dwell>99000 THEN
DISP “DWELL TIME OUT OF RANGE - ”;
GOTO 240
END IF
OUTPUT Address;"L1";Powerstart:"DM L2";Powerstop;
“DM PNS”;Noofsteps;"SPS"
OUTPUT Address;"PDT";Dwell;"MS LSP"
END
SUB Iddev(Address,Model,Fmin,Fmax,Pmin,Pmax)
DIM Ident$[36]
OUTPUT Address;"OI"
ENTER Address;Ident$
Model=VAL(Ident$[1,2])
Model Number=VAL(Ident$[3,4])
Fmin=VAL(Ident$[5,9])
Fmax=VAL(Ident$[10,14])
Pmin=VAL(Ident$[15,20])
Pmax=VAL(Ident$[21,24])
Model Prefix=Ident$[35,35]
Series=VAL(Ident$[36])
SUBEND
Figure 2-22.
681XXC PM
Controlling Power Level and Power Sweep
2-71/2-72
Appendix A
Index of GPIB Commands
A-1
INTRODUCTION
This appendix provides an alphabetical index of the GPIB Product
Specific Commands for the 681XXC. The index lists the command
mnemonic code, a brief description of the command function, and the
page number in Chapter 2 where a complete description of the command can be found.
GPIB Commands (1 of 12)
Command
Code
681XXC PM
Function
Page
Number
ACW
Activates currently scanned frequency as CW
2-14
AD1
Selects F1-DF alternate sweep
2-17
AD5
Selects F5-DF alternate sweep
2-17
AD6
Selects F6-DF alternate sweep
2-17
ADD
Opens the GPIB address parameter
2-65
ADR
GPIB address terminator
2-12
AF1
Selects F1-F2 alternate sweep
2-17
AF3
Selects F3-F4 alternate sweep
2-17
AFU
Selects Full Range alternate sweep
2-17
AL0
Set alternate sweep RF output level to L0
2-28
AL1
Set alternate sweep RF output level to L1
2-28
AL2
Set alternate sweep RF output level to L2
2-28
AL3
Set alternate sweep RF output level to L3
2-28
AL4
Set alternate sweep RF output level to L4
2-28
AL5
Set alternate sweep RF output level to L5
2-28
AL6
Set alternate sweep RF output level to L6
2-28
AL7
Set alternate sweep RF output level to L7
2-28
AL8
Set alternate sweep RF output level to L8
2-28
AL9
Set alternate sweep RF output level to L9
2-28
AM0
Turns off the external AM function
2-22
AM1
Turns on the external AM function in Linear mode
2-22
AM2
Turn on the external AM function in Log mode
2-22
AM3
Selects front panel external AM input
2-24
AM4
Selects rear panel external AM input
2-24
AM5
Selects external AM input impedance of 50W
2-24
AM6
Selects external AM input impedance of 600W
2-24
A-1
INDEX OF
GPIB COMMANDS
GPIB Commands (2 of 12)
Command
Code
AMI
Turns on the AM Measurement mode
2-26
AMS
Opens the external AM %/V sensitivity parameter
2-9
ASD
Opens the external AM dB/V sensitivity parameter
2-9
AT0
Deselects step attenuator decouple mode
2-30
Selects step attenuator decouple mode on
2-30
AT1
AUT
Sets step attenuator value to xx (´10 dB) in ALC step
attenuator decouple mode. xx is an unsigned integer between 00 and 11.
Selects Auto sweep trigger
2-16
BPN
Selects –5V for retrace and bandswitch blanking outputs
2-41
BPP
Selects +5V for retrace and bandswitch blanking outputs
2-41
CF0
Set CW mode at F0, Opens F0 parameter
2-14
CF1
Set CW mode at F1, Opens F1 parameter
2-14
CF2
Set CW mode at F2, Opens F2 parameter
2-14
CF3
Set CW mode at F3, Opens F3 parameter
2-14
CF4
Set CW mode at F4, Opens F4 parameter
2-14
CF5
Set CW mode at F5, Opens F5 parameter
2-14
CF6
Set CW mode at F6, Opens F6 parameter
2-14
CF7
Set CW mode at F7, Opens F7 parameter
2-14
CF8
Set CW mode at F8, Opens F8 parameter
2-14
CF9
Set CW mode at F9, Opens F9 parameter
2-14
CLO
Closes the open parameter
2-10
CLR
Clears data entry
2-11
CM0
Set CW mode at M0, Opens M0 parameter
2-14
CM1
Set CW mode at M1, Opens M1 parameter
2-14
CM2
Set CW mode at M2, Opens M2 parameter
2-14
CM3
Set CW mode at M3, Opens M3 parameter
2-14
CM4
Set CW mode at M4, Opens M4 parameter
2-14
CM5
Set CW mode at M5, Opens M5 parameter
2-14
CM6
Set CW mode at M6, Opens M6 parameter
2-14
CM7
Set CW mode at M7, Opens M7 parameter
2-14
CM8
Set CW mode at M8, Opens M8 parameter
2-14
CM9
Set CW mode at M9, Opens M9 parameter
2-14
CS0
Turns off the CW ramp
2-65
CS1
Turns on the CW ramp
2-65
CSB
Clears all GPIB status bytes
2-39
ATT(xx)
CTL
DB
A-2
Page
Number
Function
Copy current CW frequency and power level to current list
index
dB data terminator
2-30
2-44
2-12
681XXC PM
INDEX OF
GPIB COMMANDS
GPIB Commands (3 of 12)
Command
Code
Page
Number
DF0
Selects the F0-DF sweep mode
2-15
DF1
Selects the F1-DF sweep mode
2-15
DF5
Selects the F5-DF sweep mode
2-15
DF6
Selects the F6-DF sweep mode
2-15
DFF
Opens the DF parameter (Same as DLF)
2-8
DFM
Opens the DF parameter (Same as DLF)
2-8
DL1
Selects external detector leveling of the output power
2-27
DLF
Opens the DF parameter
2-8
DM
dBm data terminator
2-12
DU0
1. Decrements the open parameter by the step size
2. In list sweep mode with manual trigger selected,
decrements the list index by one
Turns on the secure mode (Blanks the front panel display
of Frequency, Power Level, and Modulation parameters)
Turns off the secure mode and restores front panel display
of all parameters
Deselects Dual Step sweep mode
2-17
DU1
Selects Dual Step sweep mode on
2-17
Decibel/Volt (dB/V) terminator
2-12
DN
DS0
DS1
DV
2-10
2-44
2-65
2-65
ELF
Opens the Reference Level DAC setting parameter
(in external power leveling mode)
Output value of the Reference Level DAC setting
in external power leveling mode
Selects front panel external leveling input
2-29
ELR
Selects rear panel external leveling input
2-29
EL0
Inhibits updating of the ESB2 bit 4 (RF Unlocked)
2-39
EL1
Enables updating of the ESB2 bit 4 (RF Unlocked)
2-39
EGI
EGO
2-10
2-29
EP0
Sets list index to xxxx, where xxxx = 4-digit integer
between 0000 and 1999
Sets list number to x, where x = 1-digit integer between
0 and 3
External pulse input; TTL high is RF off
2-41
EP1
External pulse input; TTL high is RF on
2-41
ES0
Inhibits End-of-Sweep SRQ generation
2-38
ES1
Enables End-of-Sweep SRQ generation
2-38
EXT
ELI(xxxx)
ELN(x)
681XXC PM
Function
2-44
2-44
Selects single sweep trigger
2-16
F0
Opens the F0 parameter
2-8
F1
Opens the F1 parameter
2-8
F2
Opens the F2 parameter
2-8
F3
Opens the F3 parameter
2-8
A-3
INDEX OF
GPIB COMMANDS
GPIB Commands (4 of 12)
Command
Code
F4
Opens the F4 parameter
2-8
F5
Opens the F5 parameter
2-8
F6
Opens the F6 parameter
2-8
F7
Opens the F7 parameter
2-8
F8
Opens the F8 parameter
2-8
F9
Opens the F9 parameter
2-8
FB0
Inhibits Extended Status Byte 1 SRQ generation
2-38
FB1
Enables Extended Status Byte 1 SRQ generation
2-38
FM0
Turns off the external FM function
2-23
FM3
Turns on the external FM funtion in Unlocked Narrow
mode
Selects front panel external FM input
2-24
FM4
Selects rear panel external FM input
2-24
FM5
Selects external FM input impedance of 50W
2-24
FM6
Selects external FM input impedance of 600W
2-24
FMD
Turns on the FM Measurement mode
2-26
FML
Turns on the external FM function in Locked mode
2-23
FMS
Opens the external FM sensitivity parameter
2-9
FM1
FMU
FMW
Turns on the external FM function in Unlocked Narrow
mode (Same as FM1)
Turns on the external FM function in Unlocked Wide mode
2-23
2-23
2-23
FUL
Opens the frequency scaling reference multipler
parameter
Selects the Full Range sweep mode
2-15
GH
GHz data terminator
2-12
FRS
GTC
GTD
GTF
GTL
GTO
GTS
GTT
GTU
GV
A-4
Page
Number
Function
2-41
Scans to the next higher preset CW frequency on a GET
(Executes a “SQF” command)
Steps the open parameter down by the step size on a GET
(Executes a “DN” command)
Executes a Fast-frequency-switching step on a GET (See
“ZL, ZEL” commands)
Steps to the next point in a dual step sweep mode on a
GET (Executes a “TSS” command)
Disables the GET functions
Triggers a single sweep on a GET (Executes a “TRS” command
Executes a complete Signal Generator self test on a GET
(Executes a “TST” command)
Steps the open parameter up by the step size on a GET
(Executes an “UP” command)
GHz per volt (GHz/V) data terminator
2-42
2-42
2-42
2-42
2-42
2-42
2-42
2-42
2-12
681XXC PM
INDEX OF
GPIB COMMANDS
GPIB Commands (5 of 12)
Command
Code
HWT
HZ
Selects external sweep trigger
Page
Number
2-16
Hz data terminator
2-12
Outputs the instrument identification string
2-31
II0
Enables updating of the ESB2 bit 7 (Parameter Changed)
2-39
*IDN?
II1
Inhibits updating of the ESB2 bit 7 (Parameter Changed)
2-39
IL1
Selects internal leveling of the output power
2-27
IM1
Turns on the Intensity marker mode
2-20
KH
kHz data terminator
2-12
KV
kHz per volt (kHz/V) data terminator
2-12
L0
Sets RF output power level to L0
2-27
L1
Sets RF output power level to L1
2-27
L2
Sets RF output power level to L2
2-27
L3
Sets RF output power level to L3
2-27
L4
Sets RF output power level to L4
2-27
L5
Sets RF output power level to L5
2-27
L6
Sets RF output power level to L6
2-27
L7
Sets RF output power level to L7
2-27
L8
Sets RF output power level to L8
2-27
L9
Sets RF output power level to L9
2-27
LA0
Inhibits updating of ESB1 bit 7 (RF Leveled)
2-39
LA1
Enables updating of ESB1 bit 7 (RF Leveled)
2-39
LDT
Opens the list sweep dwell time parameter
2-10
LE0
Inhibits Lock Error SRQ generation
2-38
LE1
Enables Lock Error SRQ generation
2-38
LEA
Learn list (in list sweep mode)
2-44
Sets list frequencies starting at the list index
2-44
Selects logarithmic step sweep
2-18
LF
LGS
LIN
Sets the list start index to xxxx, where xxxx = 4-digit integer
between 0000 and 1999
Sets the list stop index to xxxx, where xxxx = 4-digit integer
between 0000 and 1999
Selects linear power level operation
2-27
LIS
Selects linear step sweep
2-18
LO0
Turns off the Level Offset function
2-29
LIB(xxxx)
LIE(xxxx)
2-44
2-44
LO1
Turns on the Level Offset function
2-29
LOS
Opens the level offset parameter
2-9
LOG
Selects logarithmic power level operation
2-27
Sets list power levels starting at the list index
2-44
LP
681XXC PM
Function
A-5
INDEX OF
GPIB COMMANDS
GPIB Commands (6 of 12)
Command
Code
LS0
Inhibits updating of the ESB1 bit 3 (RF Locked)
2-39
LS1
Enables updating of the ESB1 bit 3 (RF Locked)
2-39
LSP
Selects the Power Sweep mode
2-29
LST
Places the 681XXC in list sweep mode
2-44
LU0
Readies the 681XXC to receive five tables of user level
calibration data from the controller.
Sends all five tables of user level calibration data to the
controller.
Turns off the active user level calibration table
2-54
LU1
Activates user level calibration table #1
2-54
LU2
Activates user level calibration table #2
2-54
LU3
Activates user level calibration table #3
2-54
LU4
Activates user level calibration table #4
2-54
LU5
Activates user level calibration table #5
2-54
LV0
Turns off leveling of the output power
2-29
M0
Opens the M0 parameter
2-8
M1
Opens the M1 parameter
2-8
M2
Opens the M2 parameter
2-8
M3
Opens the M3 parameter
2-8
M4
Opens the M4 parameter
2-8
M5
Opens the M5 parameter
2-8
M6
Opens the M6 parameter
2-8
M7
Opens the M7 parameter
2-8
M8
Opens the M8 parameter
2-8
M9
Opens the M9 parameter
2-8
MAN
Selects manual (step) sweep
2-18
MB0
Sets the enable mask byte for the Primary Status Byte
2-38
MB1
Sets the enable mask byte for Extended Status Byte 1
2-38
MB2
Sets the enable mask byte for Extended Status Byte 2
2-38
ME0
Disables the marker at the active frequency
2-20
ME1
Enables a marker at the active frequency
2-20
LUR
LUS
A-6
Page
Number
Function
2-54
2-54
MH
MHz data terminator
2-12
MK0
Turns off markers
2-20
MNT
Selects manual trigger (list sweep mode)
2-44
MOM
Turns off the AM and FM Measurement modes
2-26
MS
Milliseconds (ms) data terminator
2-12
MV
MHz per volt (MHz/V) data terminator
2-12
NS
Nanoseconds (ns) data terminator
2-12
681XXC PM
INDEX OF
GPIB COMMANDS
GPIB Commands (7 of 12)
Command
Code
2-33
ODF
Returns the external AM sensitivity value (in dB/V) to the
controller
Returns the name of the AM source (“FRONT”, “REAR”) to
the controller
Returns the external AM impedance value (in W) to the
controller
Returns the external AM sensitivity value (in %/V) to the
controller
Outputs the DF frequency value (in MHz) to the controller
OEM
Outputs the Extended SRQ Mask bytes (3 binary bytes)
2-34
OES
Outputs all three GPIB status bytes to the controller
2-34
OF0
Outputs the F0 frequency value (in MHz) to the controller
2-31
OF1
Outputs the F1 frequency value in (MHz) to the controller
2-31
OF2
Outputs the F2 frequency value in (MHz) to the controller
2-31
OF3
Outputs the F3 frequency value in (MHz) to the controller
2-31
OF4
Outputs the F4 frequency value in (MHz) to the controller
2-31
OF5
Outputs the F5 frequency value in (MHz) to the controller
2-31
OF6
Outputs the F6 frequency value in (MHz) to the controller
2-31
OF7
Outputs the F7 frequency value in (MHz) to the controller
2-31
OF8
Outputs the F8 frequency value in (MHz) to the controller
2-31
OF9
Outputs the F9 frequency value in (MHz) to the controller
2-31
OAB
OAE
OAI
OAS
OFE
OFH
OFI
OFL
OFS
OI
OL0
OL1
OL2
OL3
OL4
681XXC PM
Page
Number
Function
Returns the name of the FM source (“FRONT”, “REAR”) to
the controller
Outputs the high-end frequency value (in MHz) to the
controller
Returns the external FM impedance value (in W) to the
controller
Outputs the low-end frequency value (in MHz) to the
controller
Returns the external FM sensitivity value (in MHz/V) to the
controller
Outputs the instrument identification string to the controller
Outputs the L0 power level value (in dBm when in
mode; in mV when in linear mode) to the controller
Outputs the L1 power level value (in dBm when in
mode; in mV when in linear mode) to the controller
Outputs the L2 power level value (in dBm when in
mode; in mV when in linear mode) to the controller
Outputs the L3 power level value (in dBm when in
mode; in mV when in linear mode) to the controller
Outputs the L4 power level value (in dBm when in
mode; in mV when in linear mode) to the controller
log
log
log
log
log
2-33
2-33
2-33
2-32
2-33
2-31
2-33
2-31
2-33
2-31
2-32
2-32
2-32
2-32
2-32
A-7
INDEX OF
GPIB COMMANDS
GPIB Commands (8 of 12)
Command
Code
OM0
Outputs the L5 power level value (in dBm when in log
mode; in mV when in linear mode) to the controller
Outputs the L6 power level value 9in dBm when in log
mode; in mV when in linear mode) to the controller
Outputs the L7 power level value (in dBm when in log
mode; in mV when in linear mode) to the controller
Outputs the L8 power level value i(n dBm when in log
mode; in mV when in linear mode) to the controller
Outputs the L9 power level value (in dBm when in log
mode; in mV when in linear mode) to the controller
Outputs the Level Offset power level (in dB when in log
mode; in mV when in linear mode) to the controller
Outputs the M0 frequency value (in MHz)to the controller
2-31
OM1
Outputs the M1 frequency value (in MHz)to the controller
2-31
OM2
Outputs the M2 frequency value (in MHz)to the controller
2-32
OM3
Outputs the M3 frequency value (in MHz)to the controller
2-32
OM4
Outputs the M4 frequency value (in MHz)to the controller
2-32
OM5
Outputs the M5 frequency value (in MHz)to the controller
2-32
OM6
Outputs the M6 frequency value (in MHz)to the controller
2-32
OM7
Outputs the M7 frequency value (in MHz)to the controller
2-32
OM8
Outputs the M8 frequency value (in MHz)to the controller
2-32
OM9
Outputs the M9 frequency value (in MHz)to the controller
2-32
OL5
OL6
OL7
OL8
OL9
OLO
OMM
OPD
OPS
1. Returns the AM depth measurement value (in %) to the
controller, when the AMI command either has been or is
also programmed.
2. Returns the FM deviation measurement value (in MHz)
to the controller, when the FMD command either has been
or is also programmed.
Outputs the dwell time of the power sweep (in ms) to the
controller
Outputs the power sweep number of steps to the controller
2-32
2-32
2-32
2-32
2-32
2-32
2-33
2-33
2-33
OSD
Outputs the Primary Status Byte (1 binary byte) to the
controller
Outputs the step sweep dwell time (in ms) to the controller
2-33
OSE
Outputs the last GPIB syntax error to the controller
2-33
OSB
2-34
OSS
Outputs the primary SRQ Mask byte (1 binary byte) to the
controller
Outputs the self-test results (6 binary bytes) to the
controller
Outputs the step sweep number of steps to the controller
2-33
OST
Outputs the sweep time value (in ms) to the controller
2-33
OVN
Outputs the ROM version number string to the controller
2-33
OSM
OSR
A-8
Page
Number
Function
2-34
2-34
681XXC PM
INDEX OF
GPIB COMMANDS
GPIB Commands (9 of 12)
Command
Code
OWT
P0
Page
Number
Outputs the GPIB termination status to the contoller;
0 = CR, 1 = CRLF
Turns off the square wave/pulse modulation function
2-23
2-33
PCT
Percent (%) data terminator
2-12
PCV
Percent per volt (%/V) data terminator
2-12
PDT
Opens the power sweep dwell time parameter
2-9
PE0
Inhibits Parameter Range Error SRQ generation
2-38
PE1
Enables Parameter Range Error SRQ generation
2-38
PL1
Selects external power meter leveling of the output power
2-27
PNS
Opens the power sweep number of steps parameter
2-9
PPO
Selects normally-open contacts on the pen lift relay
2-41
PPC
Selects normally-closed contacts on the pen lift relay
2-41
PT0
Disables the Power Offset Table
2-51
PT1
Enables the Power Offset Table
2-51
PTC
Changes a Power Offset Table entry
2-51
PTL
Loads a Power Offset Table
2-51
RO0
Opens the ALC power slope pivot point frequency
parameter
Selects RF to be on at reset
2-41
RO1
Selects RF to be off at reset
2-41
PVT
2-9
RF0
Selects RF off during frequency switching in CW, step
sweep, and list sweep modes
Selects RF on during frequency switching in CW, step
sweep, and list sweep modes
Readies the 681XXC to receive a new instrument setup
from the controller
Readies the 681XXC to receive a new instrument setup
and new stored setups from the controller
Turns off the RF output
2-28
RF1
Turns on the RF output
2-28
Returns the instrument to local control
2-65
RC0
RC1
RCF
RCM
RL
2-41
2-41
2-34
2-34
RSS
Recalls an instrument setup stored in internal setup memory location M, where M = 1 to 9.
Reset a sweep if in progress
2-17
RST
Resets the instrument to its default settings
2-65
RT0
Selects RF to be off during retrace
2-41
RT1
Selects RF to be on during retrace
2-41
S0
Turns off the Master-Slave mode of operation
2-62
S1
Turns on the Master-Slave mode of operation
2-62
Outputs the current instrument setup to the controller
2-34
RSN(M1 - 9)
SAF
681XXC PM
Function
2-34
A-9
INDEX OF
GPIB COMMANDS
GPIB Commands (10 of 12)
Command
Code
SB0
Outputs the current instrument setup and all stored setups
to the controller
Inhibits Extended Status Byte 2 SRQ generation
2-38
SAM
2-34
SB1
Enables Extended Status Byte 2 SRQ generation
2-38
SDT
Opens the step sweep dwell time parameter
2-9
SE0
Inhibits Syntax Error SRQ generation
2-39
SE1
Enables Syntax Error SRQ generation
2-38
SEC
Seconds data terminator
2-12
SF1
Selects the F1-F2 sweep mode
2-15
SF3
Selects the F3-F4 sweep mode
2-15
SLDF
Opens the DF parameter of the Slave unit
2-9
SLF0
Opens the F0 parameter for the Slave unit
2-8
SLF1
Opens the F1 parameter for the Slave unit
2-8
SLF2
Opens the F2 parameter for the Slave unit
2-8
SLF3
Opens the F3 parameter for the Slave unit
2-8
SLF4
Opens the F4 parameter for the Slave unit
2-8
SLF5
Opens the F5 parameter for the Slave unit
2-8
SLF6
Opens the F6 parameter for the Slave unit
2-8
SLF7
Opens the F7 parameter for the Slave unit
2-8
SLF8
Opens the F8 parameter for the Slave unit
2-8
SLF9
Opens the F9 parameter for the Slave unit
2-8
SLM0
Opens the main power level parameter (L1) for the Slave
unit
Opens the alternate sweep power level parameter (L2) for
the Slave unit
Opens the M0 parameter for the Slave unit
SLM1
Opens the M1 parameter for the Slave unit
2-9
SLM2
Opens the M2 parameter for the Slave unit
2-9
SLM3
Opens the M3 parameter for the Slave unit
2-9
SLM4
Opens the M4 parameter for the Slave unit
2-9
SLM5
Opens the M5 parameter for the Slave unit
2-9
SLM6
Opens the M6 parameter for the Slave unit
2-9
SLM7
Opens the M7 parameter for the Slave unit
2-9
SLM8
Opens the M8 parameter for the Slave unit
2-9
SLM9
Opens the M9 parameter for the Slave unit
2-9
SL0
Turns off the ALC power slope function
2-30
SL1
Turns on the ALC power slope function
2-30
SLP
Opens the ALC power slope value parameter
2-9
SLL1
SLL2
A-10
Page
Number
Function
2-10
2-10
2-9
681XXC PM
INDEX OF
GPIB COMMANDS
GPIB Commands (11 of 12)
Command
Code
Page
Number
Opens the main power level parameter (L1) for the Slave
unit (Same as SLL1)
Recalls the next stored instrument setup in sequence
2-35
SNR
Enter the instrument serial number (SNRnnnnnnX)
2-65
SNS
Opens the step sweep number of steps parameter
2-9
SOF
Opens the frequency offset parameter for the Slave unit
2-10
SPS
Steps data terminator
2-12
SP0
Deselects non-equally spaced step sweep
2-20
SLV
SM
2-10
SP1
Selects non-equally spaced step sweep
2-20
SQ0
Disables the SRQ generation function
2-39
SQ1
Enables the SRQ generation function
2-39
SQD
Scan down to next lower preset CW frequency
2-14
SQF
Scan to next higher preset CW frequency
2-14
SQP
Turns on internal square wave modulation at 1 kHz
2-23
SQU
Scan up to next higher preset CW frequency
2-14
SSN(M1 - 9)
SSP
SW0
SW1
Saves the current instrument setup in internal setup memory location M, where M = 1 to 9
Selects step sweep (linear)
Turns off the internal or external square wave/pulse
modulation function (Same as P0)
Turns on internal square wave modulation at 400 Hz
2-34
2-18
2-23
2-23
SW3
Turns on internal square wave modulation at 1 kHz (Same
as SQP)
Turns on internal square wave modulation at 7.8125 kHz
2-23
SW4
Turns on internal square wave modulation at 27.8 kHz
2-23
SW5
Selects front panel external square wave input
2-25
SW6
Selects rear panel external square wave input
2-25
SWP
Selects analog sweep
2-18
SW2
2-23
SYZ
Opens the analog sweep, step sweep, and CW ramp time
parameter
Opens the increment/decrement step size parameter
2-13
TMS
Times terminator
2-12
SWT
2-9
TRG
Sets 0 dB of attenuation when RF is switched off in units
with a step attenuator (Option 2) installed.
Sets 40 dB (minimum) of attenuation when RF is switched
off in units with a step attenuator (Option 2) installed.
Triggers a single sweep
2-17
TRS
Triggers a single sweep
2-17
TSS
Advances sweep to next step in dual step sweep mode
2-17
TST
Starts an instrument self-test
2-63
TR0
TR1
681XXC PM
Changed: May 1999
Function
2-41
2-41
A-11
INDEX OF
GPIB COMMANDS
GPIB Commands (12 of 12)
Command
Code
UL0
Inhibits RF Unleveled SRQ generation
2-39
UL1
Enables RF Unleveled SRQ generation
2-39
UP
US
VM1
1. Increment the open parameter by step size
2. In list sweep mode with manual trigger selected,
increments the list index by one
Microseconds (ms) data terminator
2-12
2-10
2-44
Turns on the Video marker mode
2-20
VT
Volts data terminator
2-12
XL0
Opens the L0 parameter
2-8
XL1
Opens the L1 parameter
2-8
XL2
Opens the L2 parameter
2-8
XL3
Opens the L3 parameter
2-8
XL4
Opens the L4 parameter
2-8
XL5
Opens the L5 parameter
2-8
XL6
Opens the L6 parameter
2-8
XL7
Opens the L7 parameter
2-8
XL8
Opens the L8 parameter
2-8
XL9
Opens the L9 parameter
2-8
XP
Turns on the external square wave/pulse function
2-23
Equivalent to a Group Excute Trigger (GET)
2-42
Y
ZL(X000-999)
ZEL
ZPN
ZS(X000-999)
ZTL
A-12
Page
Number
Function
Loads a CW frequency into the stack at location X (fastfrequency-switching mode)
Ends frequency loading (fast-frequency-switching mode)
Sets the table pointer to point to location X (fastfrequency-switching mode)
Sets the stack pointer to point to location X (fastfrequency-switching mode)
Loads the frequency table starting at location bbbb (fastfrequency-switching mode)
2-47
2-47
2-47
2-47
2-47
681XXC PM
Changed: May 1999
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