AX5300P User Manual

AX5300P User Manual
AX5300P/AX5301
2 Ch. Isolated Analog
Output/Extension Card
with PCI Bus
User’s Manual
i
Disclaimers
The information in this manual has been carefully checked and is believed
to be accurate. AXIOMTEK Co., Ltd. assumes no responsibility for any
infringements of patents or other rights of third parties which may result
from its use.
AXIOMTEK assumes no responsibility for any inaccuracies that may be
contained in this document. AXIOMTEK makes no commitment to update
or to keep current the information contained in this manual.
AXIOMTEK reserves the right to make improvements to this document
and/or product at any time and without notice.
No part of this document may be reproduced, stored in a retrieval system,
or transmitted, in any form or by any means, electronic, mechanical,
photocopying, recording, or otherwise, without the prior written permission
of AXIOMTEK Co., Ltd.
 Copyright 2000 by AXIOMTEK Co., Ltd.
All rights reserved.
May 2000, Version A2
Printed in Taiwan
ii
ESD Precautions
Integrated circuits on computer boards are sensitive to static electricity.
To avoid damaging chips from electrostatic discharge, observe the
following precautions:
! Do not remove boards or integrated circuits from their anti-static
packaging until you are ready to install them.
! Before handling a board or integrated circuit, touch an unpainted
portion of the system unit chassis for a few seconds. This helps to
discharge any static electricity on your body.
! Wear a wrist-grounding strap, available from most electronic
component stores, when handling boards and components.
Unpacking
The board is packed in an anti-static bag. The board has components
that are easily damaged by static electricity. Do not remove the
anti-static wrapping until proper precautions have been taken. Safety
instructions in front of this User’s Manual describe anti-static
precautions and procedures.
After unpacking the board, place it on a raised surface and carefully
inspect the board for any damage that might have occurred during
shipment. Ground the board and exercise extreme care to prevent
damage to the board from static electricity.
Integrated circuits will sometimes come out of their sockets during
shipment. Examine all integrated circuits, particularly the BIOS,
processor and keyboard controller chip to ensure that they are firmly
seated. After unpacking the board, check and see if the following
items are included and in good condition. If any of the items is missing
or damaged, notify your dealer immediately.
AX5300P/AX5301 Board
CN-D 9P 180D (x2)
Cable Hoods CN-9P (x2)
AS59099 DAC Driver CD
AX5300P/AX5301 User‘s
Manual
! COM1/COM2 Ports Cable
(AX5301)
!
!
!
!
!
! Bracket (AX5301)
! Screw 3mm (x3)
(AX5301)
! Nut 3mm (x3) (AX5301)
! Bronze stick 6mm (x3)
(AX5301)
! Warranty Card
Make sure that all of the items listed above are present.
iii
What To Do If There Is A Problem
If there are damaged or missing parts, contact your supplier and/or
dealer immediately. Do not attempt to apply power to the board if
there is damage to any of its components.
Trademarks Acknowledgments
AXIOMTEK is a trademark of AXIOMTEK Co., Ltd.
IBM is a registered trademark of International Business
Machines Corporation.
MS-DOS, Microsoft C and QuickBasic are trademarks of
Microsoft Corporation.
TURBO C is a trademark of Borland Inc.
BASIC is a trademark of Dartmouth College.
Intel is a trademark of Intel Corporation.
Other brand names and trademarks are the properties
and registered brands of their respective owners.
iv
Table
Chapter 1
1.1
1.2
1.3
Chapter 3
Register Structure & Format
Programming the DAC Output
Using the Device Driver Command ...................... 20
Code Format ................................................... 21
4.2.1
4.2.2
4.2.3
4.3
4.4
4.5
4.6
AX5300P Installation .............................................. 14
AX5301 Installation ................................................ 15
Installing the Device Driver ............................ 19
4.1.1
4.2
Pin Descriptions ..................................................... 11
AX5300P/AX5301 I/O Address Mapping .......... 17
AX5300P Register Description........................ 17
Chapter 4
4.1
Setting Output Channel ..........................................7
Selecting Reference Voltage Input .......................8
Selecting Output Ranges ........................................9
Current Sink Select Jumper................................... 11
Hardware Installation ..................................... 14
2.5.1
2.5.2
3.1
3.2
Selecting Reference Voltage Input .......................5
Selecting Output Ranges ........................................6
Current Sink Select Jumper.....................................7
Connector Pin Assignments ........................... 11
2.4.1
2.5
Board Configuration and
Installation
AX5301 Jumper Settings .................................. 7
2.3.1
2.3.2
2.3.3
2.3.4
2.4
Introduction
Base I/O Port Address ...................................... 5
AX5300P Jumper Settings ................................ 5
2.2.1
2.2.2
2.2.3
2.3
Contents
General Description.......................................... 1
Features ........................................................... 1
Specifications................................................... 2
Chapter 2
2.1
2.2
of
Unipolar Output ..................................................... 21
Bipolar Output ....................................................... 22
Current Sink............................................................ 22
Isolated Circuit ............................................... 23
Wiring ............................................................. 23
Writing Data into D/A Register........................ 24
Programming Examples.................................. 25
4.6.1
4.6.2
Example Program in QBASIC 4.5........................... 25
Example Program in Turbo Pascal 5.0 .................. 27
v
4.6.3
Example Program in Turbo C 2.0 .......................... 29
Chapter 5
5.1
5.2
Calibration
Reference Voltage Adjustment ....................... 34
D/A Calibration ............................................... 35
5.2.1
5.2.2
Voltage Output Adjustment ................................. 35
Current Sink Adjustment ........................................ 37
Appendix A
Appendix B
Block Diagram
Location Diagrams
AX5300P................................................................... 41
AX5301 ..................................................................... 42
Appendix C
Technical Reference
About AD7542 .......................................................... 43
Current Sink Circuit ................................................. 44
vi
Table of Contents
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
Chapter 1
Introduction
1.1 General Description
The AX5300P/AX5301 is an isolated analog output/extension board
with PCI Bus interface. Both have two identical DAC channels
providing voltage output, and either 4-20mA or 0-20mA current loop.
Aside from a user definable external reference voltage input, both
AX5300P and AX5301 also support individually user selectable
analog outputs (unipolar or bipolar). Analog outputs range from 0V to
5V, 0V to 10V, -5V to +5V, -10V to +10V, or 4 to 20mA for process
control current loops. Isolated and protected against shorts and
ground, each analog output additionally supports one 12-bit D/A
converter, and two 9-pin D type connectors for external connection.
Both AX5300P and AX5301 efficiently serve a wide variety of
applications. The stable voltage and current outputs of AX5300P are
typical tools used when directing control value positioning. It can also
equip and deliver a programmable voltage source when generating
control signals material transfer rate, fluid flow, power consumption,
motor speed, temperature levels, etc.
1.2 Features
# 32-bit PCI Bus compatible analog output board with Plug &
Play
# Two channels of isolated analog output with 12-bit
resolution; up to 8 channels using the extension board
AX5301
# Voltage outputs: 0V to 5V, 0V to 10V, -5V to +5V, -10V to
+10V, or 4mA to 20mA
/ 0mA to 20mA for current loop
# Internal/external reference voltage available
# 500V DC channel-to-channel and channel-to-bus isolation
# Onboard DC/DC converter; two 9-pin D-type male
connectors
# Bundled with Windows 95/Windows NT driver and DOS
DEMO programs
Introduction
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AX5300P/AX5301 Analog Output/Extension Card User’s Manual
1.3 Specifications
# Analog Outputs
! Number of Channels: 2 (can be extended to 8)
! Output Current for All Range: ± 5mA max.
! Output Ranges:
0 to 5V, 0 to 10V, -5 to +5V,
-10 to +10V; 4-20mA or 0-20mA current
loop
! Input Data Coding: Straight binary (unipolar)
Offset binary (bipolar)
! Protection: For short circuit
! Voltage Output Source Impedance: 0.1Ω max.
# Accuracy
! Resolution: 12 bits
! Nonlinearity: ±1 LSB
! Differential Nonlinearity:
±1/2 LSB
! Inherent Quantizing Error: ±1/2 LSB
! Gain Error: Adjustable to zero
! Zero Error: Adjustable to zero
! System
Accuracy:
±0.0125% FSR (Voltage)
±0.02% FSR (Current)
# Thermal Characteristics
! Zero Drift: ±10µV/ o C
! Gain Drift: ±20ppm of FSR/ o C
! Differential Linearity Drift: ±3ppm of FSR/ o C
! Monotonicity: Monotonic, 0 to +60 o C
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Introduction
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
# Dynamic Performance
! Setting Time to 1/2 LSB
# 10V step: 33µs
# 5V step:
! Slew Rate:
16µs
0.3V/µs TYP (voltage)
1.2mA/µs (current)
# Interface Characteristic
! Compatible Bus: 32-bit PCI Bus compatible Plug and Play
! Isolated
500V DC
Voltage:
! No. of Locations
8 consecutive addresses
Occupied:
! Data Path:
12 bits
# Power Requirements
! +12V DC : 450mA
! +5V DC :
350mA
! Current Loop: 4-20mA
! Loop Supply
6-40V DC
Voltage:
! User Definable Reference
-10V DC to +10V DC
Voltage:
# Physical/Environmental
! Dimensions: AX5300P$106x173 mm
AX5301$80x159 mm
! Weight: AX5300P$186g
AX5301$125g
! Connector: Two male 9-pin D type connectors
! Operating Temperature Range: 0 o C to 60 o C
! Storage Temperature Range: -25 o C to 85 o C
! Relative
20% to 90%, non-condensing
Humidity:
Introduction
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AX5300P/AX5301 Analog Output/Extension Card User’s Manual
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AX5300P/AX5301 Analog Output/Extension Card User’s Manual
Chapter 2
Board Configuration and Installation
2.1 Base I/O Port Address
The AX5300P occupies eight consecutive I/O port spaces. The I/O
port base addresses are assigned by the PCI Plug & Play BIOS. From
the device driver, you can get the AX5300P base address and the slot
number to where AX5300P is plugged into. For more detailed
information, refer to the Chapter “Programming the DAC Output”.
2.2 AX5300P Jumper Settings
The user defined analog outputs range from unipolar (0V to +5V or 0V
to +10V), to bipolar (-5V to +5V or –10V to +10V), and/or from 0 to
20mA or 4 to 20mA for process control current loop. Besides –5V
and –10V, user may use an external voltage source for reference. The
following sections describe the jumper settings of AX5300P.
2.2.1 Selecting Reference Voltage Input
The three selections for reference voltage input are -5V, -10V and
Vext. Graphic descriptions of their corresponding jumper settings are
given below.
Channel #0
JP2
-10V (VREF)
JP6
- 5V (VREF) (Default setting)
JP10
EXT (VREF)
Board Configuration and Installation
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AX5300P/AX5301 Analog Output/Extension Card User’s Manual
Channel #1
JP4
-10V (VREF)
JP8
- 5V (VREF) (Default setting)
JP12
EXT (VREF)
When external reference is selected, the corresponding channel’s D/A
voltage output is from 0V to –VREF (in unipolar mode) or from –VREF
to VREF (in bipolar mode). The external voltage source ranges
from –10V to +10V.
In the succeeding sections, the abbreviation VREF will stand for the
selected reference voltage input, which may represent –5V, -10V or
external reference.
2.2.2 Selecting Output Ranges
Determine the output range of both channels by referring to the
following table.
Ch.
#0
#1
#0
#1
#0
#1
#0
#1
Jumper Pins
SW1
SW2
SW3
SW4
SW5
SW6
SW5
SW6
&
&
&
&
&
&
&
&
JP1
JP3
JP5
JP7
JP6
JP8
JP9 & JP6
JP11 & JP8
Selection
Bipolar
Bipolar
Unipolar
Unipolar
Current Sink
Current Sink
Current Sink
Current Sink
Range
-VREFto +VREF
-VREFto +VREF
0V to +VREF
0V to +VREF
0 to 20mA
0 to 20mA
4 to 20mA
4 to 20mA
For example:
Channel #0:
6
-5V (VREF) Unipolar (Default)
sw1
Bipolar
sw3
Unipolar JP5
sw5
Current JP9
JP1
Bipolar
JP2
-10V (VREF)
Unipolar
JP6
-5V (VREF)
ON: 4 to 20mA
OFF:0 to 20mA
JP10
EXT. (VREF)
Board Configuration and Installation
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
For example:
Channel #1:
-5V (VREF) Unipolar (Default)
sw2
Bipolar JP3
Bipolar
JP4
-10V (VREF)
sw4
Unipolar JP7
Unipolar
JP8
-5V (VREF)
sw6
Current JP11
NOTE:
ON: 4 to 20mA
OFF:0 to 20mA
JP12
EXT. (VREF)
Use –5V reference voltage input when the board is set to
current sink.
2.2.3 Current Sink Select Jumper
The range for current sink can be switched between 4 to 20mA to 0 to
20mA by setting JP9 (Channel #0) and JP11 (Channel #1) to OPEN.
When used under factory conditions, SHORT both jumpers to select 4
to 20mA current loops.
2.3 AX5301 Jumper Settings
The user defined analog outputs onboard the AX5301 include unipolar
(0V to +5V or 0V to +10V), bipolar (-5V to +5V or –10V to +10V), and
0 to 20mA or 4 to 20mA for process control current loop. Besides –5V
and –10V, user may use an external voltage source for reference. The
following sections describe the jumper settings of AX5301.
2.3.1 Setting Output Channel
The channel selection for output ports P1 and P2 on the AX5301
extended board are set via JP14 and JP13. User may select the
output port channel (1 each) from Channel2 to Channel7.
Board Configuration and Installation
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AX5300P/AX5301 Analog Output/Extension Card User’s Manual
For example, user can set P1 as Channel2 by setting JP14 like this:
JP14
CHANNEL 2
CHANNEL 3
CHANNEL 4
CHANNEL 5
CHANNEL 6
CHANNEL 7
User may also set P2 as Channel3 by setting JP13 like this:
JP13
CHANNEL 2
CHANNEL 3
CHANNEL 4
CHANNEL 5
CHANNEL 6
CHANNEL 7
2.3.2 Selecting Reference Voltage Input
The three selections for reference voltage input are -5V, -10V and
Vext. Their corresponding jumper settings are given below.
For P1
8
JP4
-10V (VREF)
JP5
- 5V (VREF) (Default setting)
JP6
EXT (VREF)
Board Configuration and Installation
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
For P2
JP10 -10V (VREF)
JP11 - 5V (VREF) (Default setting
JP12 EXT (VREF)
When external reference is selected, the corresponding channel’s D/A
voltage output is from 0V to –VREF (in unipolar mode) or from –VREF
to VREF (in bipolar mode). The external voltage source ranges
from –10V to +10V.
In the succeeding sections, the abbreviation VREF will stand for the
selected reference voltage input, which may represent –5V, -10V or
external reference.
2.3.3 Selecting Output Ranges
Determine the output range of both channels by referring to table
below.
Jumper Pins
P1
P2
P1
P2
P1
P2
P1
P2
SW1
SW4
SW2
SW5
SW3
SW6
SW3
SW6
&
&
&
&
&
&
&
&
JP1
JP7
JP2
JP8
JP5
JP11
JP3 & JP5
JP9 & JP11
Selection
Bipolar
Bipolar
Unipolar
Unipolar
Current Sink
Current Sink
Current Sink
Current Sink
Board Configuration and Installation
Range
-VREFto +VREF
-VREFto +VREF
0V to +VREF
0V to +VREF
0 to 20mA
0 to 20mA
4 to 20mA
4 to 20mA
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AX5300P/AX5301 Analog Output/Extension Card User’s Manual
For example:
P1: CNANNEL2, -5V (VREF), Unipolar (Default)
JP14
CHANNEL 2
CHANNEL 3
CHANNEL 4
CHANNEL 5
CHANNEL 6
CHANNEL 7
SW1
Bipolar
SW2
SW3
JP1
Bipolar
JP4
-10V (VREF)
Unipolar JP2
Unipolar
JP5
-5V (VREF)
Current JP3
ON: 4 to 20mA
JP6
OFF:0 to 20mA
EXT. (VREF)
For example:
P2 : CHANNEL3, -5V (VREF), Unipolar (Default)
JP13
CHANNEL 2
CHANNEL 3
CHANNEL 4
CHANNEL 5
CHANNEL 6
CHANNEL 7
SW4
Bipolar
SW5
Unipolar JP8
SW6
Current JP9
NOTE:
10
JP7
Bipolar
JP10
-10V (VREF)
Unipolar
JP11
-5V (VREF)
JP12
EXT. (VREF)
ON: 4 to 20mA
OFF:0 to 20mA
Use –5V reference voltage input when the board is set to
current sink.
Board Configuration and Installation
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
2.3.4 Current Sink Select Jumper
The range for current sink can be changed from 4 to 20mA to 0 to
20mA by setting JP3 ( P1) and JP9 ( P2 ) to OPEN. In factory settings,
set both jumpers as SHORT to select 4 to 20mA current loops.
2.4 Connector Pin Assignments
The analog outputs, current sink and voltage output, of the two
channels, are available through two male 9-pin D type connectors.
The AX5300P pin assignments are described below:
1
Vout 0
SINK 0
6
7
8
EXT. V0
1
2
Vout 1
3
SINK 1
2
7
3
8
4
9
6
EXT. V1
5
CHANNEL #0 P1
4
9
5
CHANNEL #1 P2
2.4.1 Pin Descriptions
Connectors #1 (P1):
Pin
Signal
1, 2, 3, 4, 5
6
7
8
9
Ground
VOUT 0
Current Sink 0
N/C
VEXT 0
Description
Analog Ground
Channel #0 Analog Voltage Output
Channel #0 Analog Current Loop
N/C
Channel #0 Analog External Voltage Input
Board Configuration and Installation
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AX5300P/AX5301 Analog Output/Extension Card User’s Manual
Connectors #2 (P2):
Pin
Signal
1, 2, 3, 4, 5
6
7
8
9
Description
Ground
VOUT 1
Current Sink 1
N/C
VEXT 1
Analog Ground
Channel #1 Analog Voltage Output
Channel #1 Analog Current Loop
N/C
Channel #1 Analog External Voltage Input
All AX5301 input and output signals are built in two 10-pin male
connector labeled P1 and P2. A cable connector, that converts the
10-pin male connector to 9-pin D-type connector, is bundled with the
AX5301 module. The AX5301 pin assignments are described below.
P1
1
3
5
7
9
P2
2 Vout
4 SINK
6
8 VEXT
10
AGND
1
3
5
7
9
AGND
2
6
1
1
2
3
3
5
4
7
9
12
2 Vout
4 SINK
6
8 VEXT
10
10
5
9
Board Configuration and Installation
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
Connectors #1 (P1):
Pin
1, 3, 5, 7, 9
2
4
6, 10
8
Signal
Ground
V OUT
Current Sink
N/C
V EXT
Description
Analog Ground
Connector#1 Analog Voltage Output
Connector#1 Analog Current Loop
N/C
Channel #1 Analog External Voltage Input
Connectors #2 (P2):
Pin
1, 3, 5, 7, 9
2
4
6, 10
8
Signal
Ground
V OUT
Current Sink
N/C
V EXT
Description
Analog Ground
Channel #2 Analog Voltage Output
Channel #2 Analog Current Loop
N/C
Channel #2 Analog External Voltage Input
Board Configuration and Installation
13
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
2.5 Hardware Installation
The AX5300P/AX5301 board is shipped with protective electrostatic
cover. When unpacking, touch the board’s electrostatically shielded
packaging with the metal frame of your computer to discharge the
accumulated static electricity prior to touching the board. Refer to the
ESD Precautions listed at the beginning of this manual.
The following summarizes the procedures the installation procedures
of AX5300P/AX5301:
WARNING:
Turn OFF the PC and all accessories connected to
the PC whenever installing or removing any
peripheral board including the AX5300P board.
2.5.1 AX5300P Installation
1. Turn OFF the PC and all power connected to other
accessories.
2. Unplug all power cords and cables from the rear
side of the PC.
3. Remove the PC cover (see your PC Operation
Guide if you are not skillful about it).
4. Find an unused expansion slot. Remove the empty
expansion slot cover and save the screw. You will
need it later when affixing back the retaining
bracket.
5. Grab the upper edge of the AX5300P board. Align
the AX5300P board’s retaining bracket with the
expansion slot rear panel. Straighten the board’s
gold finger with the expansion slot and gently push
the board into the slot.
6. Fasten the AX5300P board onto the chassis using
the screw you removed earlier.
7. Replace the PC cover and connect the cables you
detached in step 2.
8. Turn ON the PC and the power to other peripheral
devices.
14
Board Configuration and Installation
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
2.5.2 AX5301 Installation
1. Turn OFF the system power.
2. Unplug all power cords.
3. Remove the case cover if necessary.
4. Remove the top module if it is a non-stackthrough
module.
5. Align the AX5301 with the AX5300P.
6. Install three spacers and fasten them if necessary.
7. Connect the cable if necessary (P1 and P2).
8. Stack the modules to each other until the height of
the spacer (0.6”) becomes the distance between
modules. Restore all screws.
9. Repeat step 6 until all modules are set into position.
10. Return the case cover and connect all cables you
removed prior to installing the AX5301.
11. Turn On the system power.
Board Configuration and Installation
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AX5300P/AX5301 Analog Output/Extension Card User’s Manual
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AX5300P/AX5301 Analog Output/Extension Card User’s Manual
Chapter 3
Register Structure & Format
3.1 AX5300P/AX5301 I/O Address Mapping
Listed on the following table are the locations of the D/A registers.
Location
Function
Type
Base address + 0
Channel 0 control register
W
Base address + 1
Channel 1 control register
W
Base address + 2
Channel 2 control register
W
Base address + 3
Channel 3 control register
W
Base address + 4
Channel 4 control register
W
Base address + 5
Channel 5 control register
W
Base address + 6
Channel 6 control register
W
Base address + 7
Channel 7 control register
W
w : write only
3.2 AX5300P Register Description
Refer to Appendix D “Technical Reference” before proceeding with
this section. Data format for the D/A registers of AX5300P/AX5301 is
as follows:
Channel #0~#7
7
6
5
4
3
2
1
0
+0~7
X
CLR
A1
A0
D3
D2
D1
D0
D3 – D0 :
A1 A0
Control Register (Base+0~Base+7, Write only)
base
:
Data written to the register.
Operation address, used to indicate the desired loading operation
(i.e. load low byte, middle byte,. high byte, or DAC register).
Register Structure & Format
17
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
A1
A0
0
0
0
1
1
0
1
1
CLR
X
18
Description
Load D3-D0 to LOW byte data register
Load D3-D0 to MIDDLE byte data register
Load D3-D0 to HIGH byte data register
Load 12-bit DAC register with data in LOW byte,
MIDDLE byte and HIGH byte data registers.
: Always 1 unless user wants to clear the DAC register.
: Don’t care
Register Structure & Format
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
Chapter 4
Programming the DAC Output
The AX5300P device driver is suitable for Plug & Play under DOS
environment when generating information from PCI BIOS. This
chapter describes in detail on how to install the device driver and use
the device driver command to get base address, IRQ level, slot
number. Testing programs are also provided for reference.
After successfully retrieving the information, user can use the
information to act as parameter for driver function. All operations
within this section will only work if the device driver “AX5300P.SYS” is
successfully installed.
It is simple to program AX5300P with I/O output instructions in
whatever application language. With D/A’s having 12-bit resolution,
data should be within the range 0-4095 decimal. Split the data into 3
byte (low, middle and high byte). For instance, the data 1024 (Dec) is
split into 0100 (high byte), 0000 (middle byte) and 0000 (low byte), in
binary.
4.1 Installing the Device Driver
Before executing any application program (including the following
examples), this device driver must be installed. To install the device
driver, type
SETUP [SOURCE DRIVE] [TARGET DRIVE] [DIRECTORY]
This will copy the device driver to the desired directory. And then add
the following command line to your config.sys:
DEVICE = [PATH] AX5300P.SYS
Programming the DAC Output
19
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
Example
If you insert this diskette into drive A: and want to copy the file into
C:\AX5300P. You must key in the following command line at the DOS
prompt.
A:\SETUP A: C:\ AX5300P [ENTER]
Then add the following line to your config.sys file.
DEVICE = C:\AX5300P\AX5300P.SYS
Reboot your computer.
If the AX5300P is plugged in your system, the following message will
appear :
*
*
*
*
*
**********************************
Copyright 1998 by AXIOMTEK Co., LTD
Ver 1.0
AX5300P DEVICE DRIVER INSTALLED
**********************************
*
*
*
*
*
Now AX5300P acts like a file. You can OPEN, CLOSE, WRITE
(command), READ (base address, IRQ level, slot number) it via this
device driver.
If there is no AX5300P in your system, the following message will
appear:
AX5300P or PCI BIOS Not Found !!
Any attempt to OPEN the device driver will fail !
4.1.1 Using the Device Driver Command
The device driver is for the user to retrieve Base Address, IRQ Level,
and Slot Number of AX5300P plugged in your system.
Before accessing the device driver, open it as needed. After
accessing the device driver, close it as also needed. To get any
information (Base Address, IRQ Level or Slot Number), you must first
write a command to the device driver in order for the needed data to
be read from the device driver.
20
Programming the DAC Output
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
There are three commands for user to obtain Base Address, IRQ level
and Slot Number. The number following the command indicates card
number.
To get base address, you must write the command string "B?" to the
device driver and then read a WORD (two bytes) from the device
driver. This is the base address you need.
To get the IRQ level, you must write the command string "I?" to the
device driver and then read a WORD (two bytes) from the device
driver. This is the IRQ level you need.
To acquire the slot number, you must write the command string "S?"
to the device driver and then read a WORD (two bytes) from the
device driver. This is the slot number you need.
NOTE:
The question mark “?” must be replaced by a card
number. If Base Address returns to 0, it means all
information retrieved by the card number are not
available.
4.2 Code Format
The data coding (input/output relationship) for current sink, unipolar
output and bipolar output are described on the succeeding sections.
4.2.1
Unipolar Output
Analog Output(V) = (code ! 4096) x VREF
Code (Binary)
0000
0100
1000
1111
0000
0000
0000
1111
0000
0000
0000
1111
Programming the DAC Output
Output (V)
0V
VREF * (1024/4096)
VREF * (2048/4096)
VREF * (4095/4096)
21
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
4.2.2 Bipolar Output
Analog Output(V) = [(code - 2048) ! 2048] x VREF
Code (Binary)
0000
0111
1000
1111
0000
1111
0000
1111
Output (V)
0000
1111
0000
1111
-VREF * (2048/2048)
-VREF * (1/2048)
0V
+VREF * (2047/2048)
4.2.3 Current Sink
For 4 to 20mA Current Sink
Current Sink(mA) = [4 + (code ! 4096)] x (20 – 4)
Current Sink
(mA)
Code (Binary)
0000
0100
1000
1111
0000
0000
0000
1111
0000
0000
0000
1111
4
8
16
20
For 0 to 20mA Current Sink
Current Sink (mA) = (code ! 4096) x 20
Current Sink
(mA)
Code (Binary)
0000
0100
1000
1111
0000
0000
0000
1111
0000
0000
0000
1111
0
5
10
20
Code: data which is sent to DAC, its range is
from 0 – 4095.
22
Programming the DAC Output
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
4.3 Isolated Circuit
Photo-couplers are used in the isolation circuit of AX5300P/AX5301.
Any write pulse sent to DAC must pass through these photo-couplers.
This takes about 0.45 milliseconds to reach the AD7542. User must
wait before sending another 12-bit data to AX5300P.
4.4 Wiring
In this section the wiring connections from the male 9-pin D type
connectors are provided.
Analog Voltage Output
1
Vout
6
SINK
7
2
3
8
Vext
4
9
5
LOAD
NOTE:
Load resistance must not be less than (Vout/5mA).
Analog Current Sink
DEVICE
1
Vout
6
SINK
7
Rs
Vs
NOTE:
8
Vext
9
2
3
4
5
1. Vs : external power source
Rs : total loop resistance
2. For Vs = 12Vdc, Rs ≤ 325Ω (for more details, refer to
Appendix D “Current Sink Circuit”).
Programming the DAC Output
23
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
Analog External Voltage Input
The VOUT depends on the external voltage source. For instance, in
unipolar mode connect a –8V external voltage source to pin 9 of the D
type connector then the output range is from 0 to 8V.
1
Vout
SINK
6
7
8
Vext
9
2
3
4
5
EXTERNAL VOLTAGE
SOURCE (-10V to +10V)
4.5 Writing Data into D/A Register
A brief description for sending 1024 to D/A (Channel #0) is given
below. As mentioned before, first split 1024 into 0100 (high byte),
0000 (middle byte) and 0000 (low byte).
NOTE:
base = base address of channel #0
outportb = an I/O write to base address
outportb(base+0,0x40);
delay(2);
outportb(base+0,0x50);
delay(2);
outportb(base+0,0x64);
delay(2);
24
/* load 0x40 to base+0
0x40(hex)=0100 0000 (binary)
set CLR=1, A1A0=00,
D3-D0=0000 (low byte)
*/
/* delay 2 ms
*/
/* load 0x50 to base+0
0x50(hex)=0101 0000(binary)
set CLR=1,A1A0=01,
D3-D0=0000 (middle byte) */
/* delay 2 ms
*/
/* load 0x64 to base+0
0x64(hex)=0110 0100(binary)
set CLR=1,A1A0=10,
D3-D0=0100 (high byte) */
/* delay 2 ms
*/
Programming the DAC Output
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
outportb(base+0,0x70);
delay(5);
/* load 0x70 to base+0
0x70(hex)=0111 0000(binary)
set CLR=1,A1A0=11,
D3-D0 don’t care
Load 12-bit DAC register with
data in low byte, middle byte,
high byte data registers
*/
/* delay 5 ms
*/
4.6 Programming Examples
4.6.1 Example Program in QBASIC 4.5
Determine the reference voltage input and output range / mode of
AX5300P (Channel #0), refer to Section 2.2 for the setting of jumpers
and Section 4.4 for the wiring. Execute below program. Input 12-bit
data and it will be sent to the analog output of Channel #0.
DECLARE SUB DELAY (a)
‘DEMO PROGRAM FOR QB4.5 USER
‘DELAY ROUTINE
‘MAIN PROGRAM
OPEN “5300PDRV” FOR OUTPUT AS #1
OPEN “5300PDRV” FOR BINARY AS #2
PRINT #1, “B1”
GET #2, 1, BL%
GET #2, 1, BH%
PRINT #1, “S1”
GET #2, , S%
CLOSE #1
CLOSE #2
BL = BL%
BH = BH%
ADDR = BH * 256 + BL
PRINT “BASE ADDRESS: “, HEX$(ADDR)
PRINT “SLOT NUMBER: “, S%
IF ADDR <> 0 THEN PRINT “The information are correct”
‘OUT ADDR, &HFF'ENABLE AX5300P, CHANNEL 0
‘EXIT IF CH NOT 0
DO UNTIL CH <> 0
Programming the DAC Output
25
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
PRINT "TYPE CHANNEL AND DATA LIKE THIS: CHANNEL,DATA"
INPUT "INPUT DATA:"; CH, DAT
PRINT CH, DAT
'SEND LOW BYTE
DATL = DAT AND &HF
SDATL = DATL OR &H40
OUT ADDR, SDATL
DELAY (2)
'GENERATE AND SEND MIDDLE BYTE
DATM = DAT AND &HF0
DATM = DATM / 16
SDATM = DATM OR &H50
OUT ADDR, SDATM
DELAY (2)
'GENERATE AND SEND HIGH BYTE
DATH = DAT AND &HF00
DATH = DATH / 256
SDATH = DATH OR &H60
OUT ADDR, SDATH
DELAY (2)
'SEND 12-BIT DATA TO ANALOG OUTPUT
OUT ADDR, &H70
DELAY (5)
LOOP
END
SUB DELAY (a)
FOR i = 1 TO a
FOR j = 1 TO 10: NEXT j
NEXT i
END SUB
26
'1 ms delay loop
Programming the DAC Output
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
4.6.2 Example Program in Turbo Pascal 5.0
Determine the reference voltage input and output range / mode of
AX5300P (Channel #0), refer to Section 2.2 for the setting of jumpers
and Section 4.3 for the wiring. Execute below program. Input 12-bit
data and it will be sent to the analog output of Channel #0.
PROGRAM AX5300P(OUTPUT);
USES CRT,DOS;
VAR
FDW:TEXT;
FDR:FILE OF INTEGER;
ADDR,SLOTNO:INTEGER;
CODE_L,SEND_DATA_L:INTEGER;
CODE_M,SEND_DATA_M:INTEGER;
CODE_H,SEND_DATA_H:INTEGER;
DATA,SEND_DATA,PD,PW,CH:INTEGER;
BEGIN(*MAIN PROCEDURE*)
CLRSCR;
ASSIGN(FDW,'5300PDRV');
ASSIGN(FDR,'5300PDRV');
REWRITE(FDW);
WRITELN(FDW,'B1');
RESET(FDR);
READ(FDR,ADDR);
REWRITE(FDW);
WRITELN(FDW,'S1');
RESET(FDR);
READ(FDR,SLOTNO);
CLOSE(FDW);
CLOSE(FDR);
WRITELN('BASE ADDRESS :',ADDR:10);
WRITELN('SLOT NUMBER:',SLOTNO:10);
IF ADDR <> 0 THEN WRITELN('THE INFORMATION ARE CORRECT');
CH:=0;
WHILE CH=0 DO
(*IF CH <> 0 THEN EXIT*)
Programming the DAC Output
27
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
BEGIN
WRITELN('TYPE IN CHANNEL AND DATA LIKE THIS : CHANNEL
DATA');
WRITELN('INPUT DATA');
READLN(CH,DATA);
WRITELN(CH,DATA);
CODE_L:=DATA AND $000F;
SEND_DATA_L:=CODE_L OR $40;
PORT[ADDR]:=SEND_DATA_L;
DELAY(2);
CODE_M:=DATA AND $00F0;
CODE_M:=CODE_M SHR 4;
SEND_DATA_M:=CODE_M OR $50;
PORT[ADDR]:=SEND_DATA_M;
DELAY(2);
CODE_H:=DATA AND $0F00;
CODE_H:=CODE_H SHR 8;
SEND_DATA_H:=CODE_H OR $60;
PORT[ADDR]:=SEND_DATA_H;
DELAY(2);
SEND_DATA:= $70;
PORT[ADDR]:=SEND_DATA;
DELAY(2);
END;
END.
28
Programming the DAC Output
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
4.6.3 Example Program in Turbo C 2.0
Set jumpers to –5V reference and current sink mode, refer to Section
2.2 for the jumper setting and Section 4.3 for the wiring. Execute
below program and follow the instructions shown on screen. This
program allow you to input data in mA which will be converted to
binary and sent to the analog current loop of the selected channel.
#include
#include
#include
#include
#include
#include
#include
<stdio.h>
<dos.h>
<string.h>
<conio.h>
<stdlib.h>
<fcntl.h>
<io.h>
main()
{
unsigned int ch, cur_sink, code,BASE;
unsigned l_byte, m_byte, h_byte;
int fd,base,busno,ans;
if ((fd=open("5300Pdrv",O_RDWR))==-1){
printf("AX5300P OPEN FAIL!\n");
exit(0);
}
else
printf("OK\n");
write(fd,"B1",2);
read(fd,&base,sizeof(int));
write(fd,"s1",2);
read(fd,&busno,sizeof(int));
close(fd);
printf("BASE ADDRESS : %x\n",base);
printf("SLOT NUMBER :%x\n",busno);
if (base==0){
printf("ERROR INFORMATION !\n");
exit(0);
}
Programming the DAC Output
29
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
clrscr();
ans = 'y';
while (ans == 'y')
{
printf("Please Select Channel Number -- #0 or #1\n");
printf("Channel : #");
scanf("%d",&ch);
if (ch==0)
BASE = base;
else if (ch==1)
BASE = base+1;
else
{
printf("Wrong number of channel !\n\n");
continue;
}
printf("Please input the current sink (4 to 20 mA): ");
scanf("%d", &cur_sink);
if (cur_sink < 4 || cur_sink > 20)
{
printf("Current sink out of range\n\n");
continue;
}
else if (cur_sink == 20)
code = 4095;
else
/*refer to equation in section 4.1.3*/
code = (cur_sink - 4) * 256;
printf("Code (Dec) = %d",code);
/*generate low byte*/
l_byte = code & 0x000f;
/*shift middle byte 4 places right*/
m_byte = (code & 0x00f0) >> 4;
/*shift high byte 8 places right*/
h_byte = (code & 0x0f00) >> 8;
/*control signal for loading low byte*/
outp(BASE ,(l_byte | 0x40));
delay(2);
30
Programming the DAC Output
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
/*control signal for loading middle byte*/
outp(BASE +0,(m_byte | 0x50));
delay(2);
/*control signal for loading high byte*/
outp(BASE +0,(h_byte | 0x60));
delay(2);
/*control signal for loading the three 4-bit bytes into the DAC*/
outp(BASE +0, 0x70);
delay(2);
printf("\nDo you want to continue (y/n) ? ");
ans = getch();
putch(ans);
printf("\n\n");
}
}
Programming the DAC Output
31
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
This page does not contain any information.
32
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
Chapter 5
Calibration
The AX5300P/AX5301 D/A calibration is separated into two parts
(both parts depend on each other) :
1. Reference voltage adjustment
2. D/A calibration :
a. Voltage output adjustment
b. Current sink adjustment
Use a 3½-digit voltmeter and current meter for measurement in the
calibration. Before distribution, all AX5300P have been calibrated at
the factory. But to ensure that no change in calibration has occurred
during distribution, it is suggested that you do the D/A calibration
before using this analog output board (refer to Appendix C when
locating the trim resistors).
The reference voltage adjustment is needed only if the original
calibration from factory has deviated. The calibration procedures of
Channel #0 and Channel #1 are similar. In this chapter, we will only
provide the calibration procedure of Channel #0. Simply replace the
VR, JP, and SW of Channel #0 with those of Channel #1, refer to the
table below :
CHANNEL #0
VR1
VR2
VR3
VR4
VR5
SW1
SW3
SW5
JP1
JP5
JP9
JP2
JP6
JP10
Calibration
----->
----->
----->
----->
----->
----->
----->
----->
----->
----->
----->
----->
----->
----->
CHANNEL #1
VR6
VR7
VR8
VR9
VR10
SW2
SW4
SW6
JP3
JP7
JP11
JP4
JP8
JP12
33
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
The calibration procedures of AX5301 are similar to that of AX5300P.
Simply replace the VR, JP, and SW of AX5300P Channel#0 with
those of AX5301 P1 and P2, refer to the table below:
CHANNEL #0 OF
AX5300P
VR1
VR2
VR3
VR4
VR5
SW1
SW3
SW5
JP1
JP5
JP9
JP2
JP6
JP10
----->
----->
----->
----->
----->
----->
----->
----->
----->
----->
----->
----->
----->
P1
OF AX5301
VR1
VR2
VR3
VR4
VR5
SW1
SW2
SW3
JP1
JP2
JP3
JP4
JP5
JP6
P2
OF AX5301
VR6
VR7
VR8
VR9
VR10
SW4
SW5
SW6
JP7
JP8
JP9
JP10
JP11
JP12
5.1 Reference Voltage Adjustment
The reference voltage input is user definable to either -5V or –10V.
Only do this part of calibration if your reference voltage needs
adjustment. After the reference voltage has been fixed to –5V
(or –10V), proceed to the D/A calibration for your voltage output and
current sink adjustment. A brief description is given below.
1. To set the reference voltage input to –5V, configure
the following jumper settings as follows:
JP2 -10V (VREF)
JP6
- 5V (VREF) (Default setting)
JP10 EXT (VREF)
34
Calibration
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
Connect your voltmeter to TP5 and with the other
end of its test lead kit to TP8 (Analog Ground).
Adjust VR5 until the voltmeter shows –5.00V.
2. To set the reference voltage input to –10V after
doing step(1), proceed directly by changing the
placement of jumper caps as follows:
JP2
-10V (VREF)
JP6
- 5V (VREF)
JP10
EXT (VREF)
Connect your voltmeter to TP5 and TP8 (analog
ground). Adjust VR4 until the voltmeter
reads –10.00V. Adjusting VR4 in step(2) will cause
deviation to the –5V voltage reference input in step
(1). Repeat steps (1) and (2) twice until both
voltage reference inputs are as close to the desired
voltage references as possible.
5.2 D/A Calibration
The D/A calibration is divided into two steps: voltage output and
current sink adjustment.
5.2.1 Voltage Output Adjustment
In Bipolar Mode, follow the instructions below.
a. Put your jumper caps as shown in the following diagram.
Calibration
SW1
Bipolar
SW3
Unipolar JP5
Unipolar
SW5
Current JP9
ON: 4 to 20mA
OFF:0 to 20mA
JP1
Bipolar
35
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
b. If the board uses –5V as reference voltage, set JP6 as follows:
JP2
-10V (VREF)
JP6
-5V (VREF)
EXT. (VREF)
JP10
Connect your voltmeter to TP1 and TP8 (Analog ground).
Send data 0 (decimal) to the D/A. Adjust VR5 until the
voltmeter reads –5.00V. Again send data 4095 (decimal) to the
D/A and adjust VR3 until the voltmeter reads +5.00V.
c. If the board uses –10V as reference voltage, repeat step(b) but
set JP2 as follows:
JP2
-10V (VREF)
JP6
- 5V (VREF)
JP10
EXT (VREF)
When data 0 (decimal) and 4095 (decimal) is sent to the D/A,
the voltmeter must read –10.00V (adjust VR4) and +10.00V
(adjust VR3) respectively.
In Unipolar mode, perform the following steps:
a. Put your jumpers cap as follows:
36
SW1
Bipolar
JP1
Bipolar
SW3
Unipolar JP5
Unipolar
SW5
Current JP9
ON: 4 to 20mA
OFF:0 to 20mA
Calibration
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
b. If the board uses –5V as reference voltage, set JP6 as follows:
JP2
-10V (VREF)
JP6
-5V (VREF)
JP10
EXT. (VREF)
Connect your voltmeter to TP1 and TP8 (Analog ground).
Send data, for instance 4095 (decimal), to the D/A and adjust
VR5 if the voltmeter doesn’t read +5.00V.
c. If the board uses –10V as reference voltage, set JP2 as
follows:
JP2
-10V (VREF)
JP6
-5V (VREF)
JP10
EXT. (VREF)
Connect your voltmeter to TP1 and TP8 (Analog ground). Send
data, for instance 4095 (decimal), to the D/A and adjust VR4 if
the voltmeter doesn’t read +10.00V.
5.2.2 Current Sink Adjustment
Here you will need to adjust two trim resistors: VR1 and VR2.
Follow the instructions below:
a. Set jumpers as follows :
SW1
Bipolar
SW3
SW5
Calibration
JP1
Bipolar
JP2
-10V (VREF)
Unipolar JP5
Unipolar
JP6
-5V (VREF)
Current JP9
ON: 4 to 20mA
OFF:0 to 20mA
JP10
EXT. (VREF)
37
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
b.
R
A
TP6
TP8
100
8-25VDC
Connect your current meter to TP6 and TP8 as illustrated
above.
c. Send data 0 (decimal) to the D/A. Adjust VR1 until the current
meter shows 4.00mA.
d. Without removing the current meter from TP6 and TP8. Send
data 4095 (decimal) to the D/A. Adjust VR2 until the current
meter reads 20.00mA.
e. The procedure above is for the 4-20mA current loop
adjustment. If the current output is set to 0-20mA by opening
JP9 (channel #0) or JP11 (channel #1), repeat steps (a) and
(b). Then you will only need to send data 4095 (decimal) to the
D/A. Adjust VR2 until the current meter reads 20.00mA.
38
Calibration
Block Diagram
B
U
S
P
C
I
BRIDGE
PCI
ISOLATION
DEVICE
I
S
O
L
A
T
I
O
N
ISOLATION
DEVICE
DATA BUS
CONTROL
BUS
DATA BUS
CONTROL
BUS
D/A
CONVERTER
ISOLATION
POWER
D/A
CONVERTER
ISOLATION
POWER
ISOLATION
REFERENCE
VOLTAGE
AMPLIFIER
CURRENT
SINK
CIRCUIT
ISOLATION
REFERENCE
VOLTAGE
AMPLIFIER
CURRENT
SINK
CIRCUIT
EXTERNAL
REFERENCE
(CHANNEL#0)
VOLTAGE
OUT
(CHANNEL#0)
CURRENT
SINK
EXTERNAL
REFERENCE
(CHANNEL #1)
VOLTAGE
OUT
(CHANNE #1)
CURRENT
SINK
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
Appendix A
Block Diagram
39
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
This page does not contain any information.
40
Location Diagrams
P2
P1
TP6
TP1
TP5
TP8
SW1 JP1 JP2
SW3 JP5 JP6
SW5 JP9 JP10 VR1 VR2 VR3 VR4 VR5
TP2
TP3
TP4
TP7
SW2 JP3 JP4
SW4 JP7 JP8
SW6 JP11 JP12 VR6 VR7 VR8 VR9 VR10
39
1
40
JP13
2
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
Appendix B
Location Diagrams
AX5300P
41
42
TP1
P1
TP2
SW1
SW2
SW3
JP1
JP2
JP3
TP3
JP4
JP5
JP6
VR1 VR2 VR3 VR4 VR5
TP4
SW4
SW5
SW6
P2
JP7
TP5 JP8
JP9
TP6
JP10
JP11
JP12
VR6 VR7 VR8 VR9 VR10
TP8
TP7
JP15
JP13 JP14
39 40
1 2
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
AX5301
Location Diagrams
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
Appendix C
Technical Reference
About AD7542
The DAC used within the board is AD754, it has three 4-bit data
registers and one 12-bit DAC register. Data is loaded into the data
registers in three 4-bit bytes, and subsequently transferred to the
12-bit DAC register.
Since the D/A’s have 12-bit resolution, the digital data consist of: low,
middle and high bytes. The byte, which is being sent, is determined by
the operation address (A1, A0 refer to the following truth table).
Low-byte is written and stored in middle-byte data register and
high-byte data register respectively. At last transfer all of the data
registers into a 12-bit DAC register.
Each time the PC or system power is turned ON, it simultaneously
sets the CLR of AD7542 to active. The active CLR clears the DAC to
0000 0000 0000. When operating the AD7542 in a unipolar mode, an
active CLR causes the DAC output to assume 0V. In the bipolar mode,
an active CLR causes the DAC output to go to –VREF.
AD7542 Truth Table
AD7542 Control Inputs
AD7542 Operation
A1
A0
WR CLR
X
X
X
0
Reset DAC 12-bit register to 0000 0000 0000
Load LOW byte data register on
0
0
1
Load data
edge as shown
Load MIDDLE byte data register register with
0
1
1
data at D3~D0
on edge as shown
Load HIGH byte data register on
1
0
1
edge as shown
Load 12-bit DAC register with data in LOW byte,
1
1
1
MIDDLE byte and HIGH byte data register
Technical Reference
43
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
NOTE: 1. 1 includes logic high
2. 0 includes logic low
3. X indicates don't care
4.
indicates low to high transition
XXXX XXXX XXXX← LSB
high middle
low
byte
byte
byte
Current Sink Circuit
AX5213 provides a 4-20mA current sink loop, which is controlled from
VA output (0 to 4.9976V). The following diagram shows its application
connection and calculation.
Vs (12V)
Rs
VA
Ib
-5VREF
Rbb
+
1 3
-
2
Is
Rb
Ia
Ra
Raa
1. When VA = 0V, Is = 4mA
→ Ia = 0
Ib = 4mA = 0-(-5Vref)
=
5V
(Rb+Rbb)
(Rb+Rbb)
→ (Rb+Rbb) = 1.25K
2. When VA = 4.9976, Is = 20mA
→ Ib =
4.9976 + 5 = 7.998mA
1.025K
Ia = 20mA – 7.998mA = 12.002mA
→ (Rb+Rbb) =
4.9976V
= 416.4Ω
12.002mA
(Raa enables user to adjust for an accurate Is → 20mA)
44
Technical Reference
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
Rs and Vs are a load resistance and an external power source
respectively. The limitation of Rs is as follows:
Rs * Is + VA(max) < Vs –0.5V
At normal use, VA(max) = 4.9976V
Is = 20mA
When Vs = 12V, Rs must be less than 325Ω
AXIOMTEK recommends the use of a 250Ω for Rs to generate 1 to
5V load voltage which is proportional to 4 to 20mA.
Technical Reference
45
AX5300P/AX5301 Analog Output/Extension Card User’s Manual
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46
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