ADLINK Technology PXI-7921 User manual

PXI-7921
24-ch, Multiplexer DPDT Relay Module
User’s Manual
Manual Rev.: Rev. 1.1
Date: February 8, 2020
Part Number: 50-17011-1010

Copyright © 2004, 2020 ADLINK Technology Inc. All Rights Reserved.
Revision History.
1.00
09-07-2004
Initial release
1.1
08-02-2020
Remove Star Trigger Out functionality
Disclaimer
The information in this document is subject to change without prior notice in
order to improve reliability, design, and function and does not represent a
commitment on the part of the manufacturer.
In no event will the manufacturer be liable for direct, indirect, special,
incidental, or consequential damages arising out of the use or inability to use
the product or documentation, even if advised of the possibility of such
damages.
This document contains proprietary information protected by copyright. All
rights are reserved. No part of this manual may be reproduced by any
mechanical, electronic, or other means in any form without prior written
permission of the manufacturer.
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ADLINK Technology Inc. Other product names mentioned herein are used
for identification purposes only and may be trademarks and/or registered
trademarks of their respective companies.

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global environmental preservation through compliance
with the European Union's Restriction of Hazardous
Substances (RoHS) directive and Waste Electrical and
Electronic Equipment (WEEE) directive. Environmental
protection is a top priority for ADLINK. We have enforced
measures to ensure that our products, manufacturing
processes, components, and raw materials have as little
impact on the environment as possible. When products
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and/or recovery programs prescribed by their nation or
company.
Battery Labels (for products with battery)
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California Proposition 65 Warning
WARNING: This product can expose you to chemicals including
acrylamide, arsenic, benzene, cadmium, Tris(1,3-dichloro-2-
propyl)phosphate (TDCPP), 1,4-Dioxane, formaldehyde, lead,
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Table of Contents • i
Table of Contents
How to Use This Manual..............................................................ii
Chapter 1 Introduction ..............................................................1
1.1 Features.............................................................................1
1.2 Applications .......................................................................2
1.3 Specifications.....................................................................2
1.4 Software Support...............................................................3
Chapter 2 Installation ................................................................5
2.1 Unpacking..........................................................................5
2.2 Mechanical Drawing...........................................................6
2.3 Installing the switch module into a PXI Platform................6
Chapter 3 Signal Connection....................................................9
3.1 PXI-7921 Topology............................................................9
3.2 PXI-7921 Pin Assignments & Descriptions......................10
3.3 TB-6221 Terminal Board..................................................13
2-wire MUX........................................................................14
2-wire, 2-group MUX..........................................................15
2-wire, 4-group MUX..........................................................16
1-wire MUX........................................................................17
4-wire MUX........................................................................18
Chapter 4 Operation Theorem................................................19
4.1 Hardware Block Diagram.................................................19
4.2 Operation Mode...............................................................20
4.3 Handshaking....................................................................20
4.4 Trigger Bus ......................................................................24
4.5 Auxiliary Digital I/O...........................................................26
4.6 Hot-Swap.........................................................................27
4.7 Emergency Shutdown......................................................27
4.8 Watchdog Timer...............................................................28
Warranty Policy........................................................................31

ii • How to use this Manual
How to Use This Manual
This User Manual is designed to assist users in the installation of the ADLINK
PXI-7921, 24-ch Multiplexer DPDT Relay PXI Switch module.
Chapter 1 Introduction
Gives an outline and overview of ADLINK switch modules’
features, specifications, and applications.
Chapter 2 Installation
Describes how to install a switch module into a PXI chassis. For
software library and utilities installation, please refer to the
Software Users’ Guide.
Chapter 3 Signal Connection
Shows the pin assignments and terminal board connection of the
switch module.
Chapter 4 Operation Theorem
Describes function blocks on ADLINK switch modules and
operation instructions.

Introduction • 1
Introduction
ADLINK PXI-7921 is a relay multiplexer module which consists of 24 2-wire
relays (DPDT, 2 Form C). PXI-7921 provides 48x1 1-wire and 24x1 2-wire and
12x1 4-wire configurations and typically connects one instrument, such as a
DMM, a digitizer or a signal source, with many points which need measurement
or excitation.
Relays of PXI-7921 can be updated by either direct-update mode or auto-scan
mode. The latter mode supports scanlist of 1k-sample for deterministic
scanning.
PXI trigger functions are fully supported and software programmable. The
multiple switch modules can be synchronized and triggered without additional
field wiring.
For safety critical applications, PXI-7921 module can switch to the preset state
by either asserting emergency shutdown manually, or watchdog timer overflow
event.
1.1 Features
•PXI specifications Rev. 2.0 compliant
•3U Eurocard form factor, CompactPCI compliant (PICMG 2.0R3.0)
•PICMG 2.1 R2.0 CompactPCI Hot-Swap specificationscompliant
•24-ch DPDT (2 Form C) non-latching relays
•Contact rating
•2A switching, 2Acarrying
•220VDC, 125VAC
•125 operations per second
•1k-sample scanlist for deterministic scanning
•Provides handshaking signals to trigger external instruments
•Programmable emergency shutdown function and Watchdog timer for
safety critical applications
•Three auxiliary 3.3V/TTL digital inputs/outputs with 5V tolerance
•Supports PXI backplane triggers to synchronize multiple modules
•Fully software programmable
1

2 • Introduction
1.2 Applications
•Industrial ON/OFF control
•External high power relay driving and signal switching
•Laboratory automation
•Industrial automation
•Switch contact status sensing
•Limit switch monitoring
•Cooperating with other modules such as A/D and D/Aperipherals to
implement a data acquisition and control system
1.3 Specifications
Relay Output
•Number of channels: 24
•Relay type: DPDT (2 Form C), non-latching
•Switching capacity:
•Max. switching current: 2A
•Max. switching voltage: 220VDC, 125VAC
•Max. switching power: 50VA, 60W
♦Max. carrying current: 2A
•Failure rate: 10µA
•Contact resistance: 100mΩ max.
•Relay set/reset time
•Operate time: 4msmax.
•Release time: 4msmax.
•Bounce time: 1ms max.
•Expected life:
•Mechanical life: 108operations min.
•Electrical life: 5x105operations min. (1A @ 30VAC, resistiveload)
•Data transfer: Programmed I/O
Auxiliary Digital I/O
•Numbers of channel: 3inputs/outputs
•Compatibility: 3.3 V/TTL (5Vtolerant)
•Data transfers: programmed I/O
Handshaking Signals
•Programmable polarity
•Logic level: 3.3 V/TTL (5V tolerant)
•Trigger In source: TRG_IN, PXI trigger bus, PXI star trigger in
•Scanner Advanced destination: S_ADV, PXI trigger bus

Introduction • 3
Safety functions
•Emergency shutdown
•Logic level: 3.3 V/TTL (5V tolerant)
•Active with logic low (for AUX2/SHDNn pin)
•Emergency shutdown sources: SHDNn, PXI star trigger input, PXI
trigger bus
•Watchdog timer
•Base clock available: 10MHz, fixed
•Counter width: 32-bit
•Watchdog Timer Overflow sources: Onboard 32-bitwatchdog
timer, PXI star trigger input, PXI trigger bus
General Specifications
•I/O Connector: 62-pin D-submale
•Operating temperature: 0 to55°C
•Storage temperature: -20 to70°C
•Humidity: 5 to 95% non-condensing
•Power requirements (when all relays are activated simultaneously)
+5V +3.3V
1A 400mA
•Dimensions (not including connectors)
•160 mm x 100 mm
1.4 Software Support
ADLINK's ADL-SWITCH driver package is for Microsoft Windows operating
systems, including Windows 98/ME/NT/2000/XP.
The driver package also provides utilities to test your switch module, as well as
programming samples and source codes in Microsoft Visual Basic and Visual
C/C++.
For other operating systems, please contact ADLINK for more information.

4 • Introduction
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Installation • 5
Installation
This chapter describes the installation process for the ADLINK switch module.
Please read the contents of the package and the disassembling information
carefully as they are important in the implementation of the ADLINK switch
module.
2.1 Contents
The package consists of the following items in addition to the User Manual:
•PXI-7921, 24-ch Multiplexer DPDT Relay module
•This User’s Guide
•ADLINK Software CD
•ADL-Switch User’s Guide
If any of these items are missing or broken, please do not hesitate to contact
ADLINK or the dealer from whom the product was purchased. Keep the
shipping materials and carton for future storage or shipping.
2.2 Unpacking
ADLINK switch module contains sensitive electronic components that can be
easily damaged by static electricity. The switch module should be operated on a
grounded anti-static mat. It is strongly recommended that the operator wears an
anti-static wristband, grounded at the same point as the anti-staticmat.
Inspect the box for any obvious damage. Check the unit to ensure there are no
shipping and handling damages that may have occurred before proceeding.
After opening, remove the system module and place it only on a grounded anti-
static surface component side up.
Again, inspect the module for any damage. Press down on all the socketed IC’s
to make sure they are all properly seated. Please do this only on a firm and flat
surface.
2

Note: Do not apply power to the module if it has been damaged.
You are now ready to install the PXI-7921.
2.3 Mechanical Drawing
Figure 1: ADLINK Switch Module
ADLINK switch module is packaged in a Eurocard form factor compliant with
PXI Specifications measuring 160 mm in length and 100 mm in height (not
including connectors). A 62-pin connector is located at the front panel for wiring
purposes and the J1/J2 IEC connectors in the rear are used to link the chassis
backplane. With its modular, rugged, and high shock resistant mechanical
features, the switch module functions exceptionally well in any harsh
environment application.
2.4 Installing the switch module into a PXI Platform
To insert the ADLINK PXI switch module, align the module’s edge with the card
guide in the PXI chassis. Slide the switch module into the chassis, until
resistance is felt from the PXI connector. Push the ejector upwards and fully
6 • Installation

Installation • 7
insert the switch module into the chassis. Once inserted, a “click” can be heard
from the ejector latch. Tighten the screws on the front panel.
Figure 2: Installing the switch module into a PXI platform

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8 • Installation

Signal Connection • 9
Signal Connection
3.1 PXI-7921 Topology
The ADLINK PXI-7921 is the armature relay multiplexer module which
consists of a 24×1 2-wire multiplexer. It also can operate as two groups of
12x1 2-wire multiplexer, four groups of 6×1 2-wire multiplexer, one group of
48×1 1-wire multiplexer, or one group of 12×1 4-wire multiplexer. These
configurations are totally software programmable.
The PXI-7921 typically connects one instrument, such as a DMM or digitizer,
to many measurement points or a signal source to several points needing
excitation. Without jumper settings, complete software programming makes
PXI-7921 easy-to-use and dedicated for versatile applications. PXI-7921
fully supports PXI trigger functions. Multiple switch modules can therefore be
synchronized or triggered without additional field-wiring.
3

10 • Signal Connection
3.2 PXI-7921 Pin Assignments & Descriptions
22. +5 VOUT
43. COM2+
23. CH8+
1. CH0+
44. COM2-
24. CH8-
2. CH0-
45. COM3+
25. CH9+
3. CH1+
46. COM3-
26. CH9-
4. CH1-
47. CH18+
27. CH10+
5. CH2+
48. CH18-
28. CH10-
6. CH2-
49. CH19+
29. CH11+
7. CH3+
50. CH19-
30. CH11-
8. CH3-
51. CH20+
31. CH12+
9. CH4+
52. CH20-
32. CH12-
10. CH4-
53. CH21+
33. CH13+
11. CH5+
54. CH21-
34. CH13-
12. CH5-
55. CH22+
35. CH14+
13. COM0+
56. CH22-
36. CH14-
14. COM0-
57. CH23+
37. CH15+
15. COM1+
58. CH23-
38. CH15-
16. COM1-
59. 1WireloRef*
39. CH16+
17. CH6+
60. TRG_IN
40. CH16-
18. CH6-
61. S_ADV
41. CH17+
19. CH7+
62. SHDNn
42. CH17-
20. CH7-
21. GND
*not used in two-wire mode
Table 1: Pin Assignment (2 wire)

Signal Connection • 11
22. +5 VOUT
43. COM2+*
23. CH8
1. CH0
44. COM2-*
24. CH32
2. CH24
45. COM3+*
25. CH9
3. CH1
46. COM3-*
26. CH33
4. CH25
47. CH18
27. CH10
5. CH2
48. CH42
28. CH34
6. CH26
49. CH19
29. CH11
7. CH3
50. CH43
30. CH35
8. CH27
51. CH20
31. CH12
9. CH4
52. CH44
32. CH36
10. CH28
53. CH21
33. CH13
11. CH5
54. CH45
34. CH37
12. CH29
55. CH22
35. CH14
13. COM0+
56. CH46
36. CH38
14. COM0-
57. CH23
37. CH15
15. COM1+*
58. CH47
38. CH39
16. COM1-*
59. 1WireloRef
39. CH16
17. CH6
60. TRG_IN
40. CH40
18. CH30
61. S_ADV
41. CH17
19. CH7
62. SHDNn
42. CH41
20. CH31
21. GND
*not used in one-wire mode
Table 2: Pin Assignment (1 wire)
22. +5 VOUT
43. COM2+
23. CH8A+
1. CH0A+
44. COM2-
24. CH8A-
2. CH0A-
45. COM3+
25. CH9A+
3. CH1A+
46. COM3-
26. CH9A-
4. CH1A-
47. CH6B+
27. CH10A+
5. CH2A+
48. CH6B-
28. CH10A-
6. CH2A-
49. CH7B+
29. CH11A+
7. CH3A+
50. CH7B-
30. CH11A-
8. CH3A-
51. CH8B+
31. CH0B+
9. CH4A+
52. CH8B-
32. CH0B-
10. CH4A-
53. CH9B+
33. CH1B+
11. CH5A+
54. CH9B-
34. CH1B-
12. CH5A-
55. CH10B+
35. CH2B+
13. COM0+
56. CH10B-
36. CH2B-
14. COM0-
57. CH11B+
37. CH3B+
15. COM1+
58. CH11B-
38. CH3B-
16. COM1-
59. 1WireloRef*
39. CH4B+
17. CH6A+
60. TRG_IN
40. CH4B-
18. CH6A-
61. S_ADV
41. CH5B+
19. CH7A+
62. SHDNn
42. CH5B-
20. CH7A-
21. GND
*not used in four-wire mode
Table 3: Pin Assignment (4 wire)

12 • Signal Connection
Signal Name
Type
Description
COM0± (one wire)
COM<0..3>± (two wire)
COM<0..1>A±(four
wire) COM<0..1>B±
(four wire)
Input/Output
Common---The common for each
bank.
CH<0..47> (one wire)
CH<0..23>± (two wire)
CH<0..11>A± (four wire)
CH<0..11>B± (four wire)
Input/Output
Channels---Where signals are
connected to the switch card. CHχ+
and CHχ- are switched together.
1WireLoRef
Input/Output
1 Wire Low Reference---The common
reference signal used in one-wire
mode.
TRG-IN
Input
Trigger Input---Trigger from an
instrument to advance the switch
card to
the next scan entry.
S_ADV
Output
Scanner Advanced---Trigger to an
instrument that indicated the switch
card has advanced to the next scan
and relays
are debounced.
SHDNn
Input
Emergency Shutdown---The trigger
used
to shutdown the system.
+5V OUT
Output
+5V VDC Source---Provide +5 power
pin.
GND
Output
Ground---Provide system ground pin.
COM0± (one wire)
COM<0..3>± (two wire)
COM<0..1>A±(four
wire)
COM<0..1>B± (four wire)
Input/Output
Common---The common for each
bank.
CH<0..47> (one wire)
CH<0..23>± (two wire)
CH<0..11>A± (four
wire)
CH<0..11>B± (four wire)
Input/Output
Channels---Where signals are
connected to the switch card. CHχ+
and CHχ- are switched together.
Table 4: Pin Description

Signal Connection • 13
3.3 TB-6221 Terminal Board
Users can use the TB-6221 terminal board that consists of a printed circuit
with screw terminals. The terminal block connects directly to the front panel
I/O connector of the PXI-7921.
The TB-6221’s default printed circuit is in 2-wire mode. If other configuration
is preferred, user can refer the table on TB-6221 to identify the pin
connected.

14 • Signal Connection
2-wire MUX
This configuration has one 24x1 2-wire multiplexer Bank0, which has twenty-
four channels. The following diagram illustrates the terminal board pin
definition.
Figure 3: 24x1 MUX