Keysight Technologies 34921A, 34922A, 34923A, 34924A, 34925A User Manual

Keysight 34921A-34925A Low Frequency Multiplexer Modules

User’s Guide

Notices

CAUTION

WARNING

Copyright Notice

reproduced in any form or by any means (including electronic storage and retrieval or translation into a foreign language) without prior agreement and written consent from Keysight Technologies as governed by United States and international copyright laws.

Trademarks

Microsoft® and Windows® are U.S. registered trademarks of Microsoft Corporation.

Manual Part Number

34980-90021

Edition

Edition 3, July 1, 2019

Printed in:

Printed in Malaysia

Published by:

Keysight Technologies Bayan Lepas Free Industrial Zone, 11900 Penang, Malaysia

Technology Licenses

The hard ware and/or software described in this document are furnished under a license and may be used or copied only in accordance with the terms of such license.

Declaration of Conformity

Declarations of Conformity for this product and for other Keysight products may be downloaded from the Web. Go to http://www.keysight.com/

go/conformity. You can then search by

product number to find the latest Declaration of Conformity.

U.S. Government Rights

The Software is “commercial computer software,” as defined by Federal Acquisition Regulation (“FAR”) 2.101. Pursuant to FAR 12.212 and 27.405-3 and Department of Defense FAR Supplement (“DFARS”) 227.7202, the U.S. government acquires commercial computer software under the same terms by which the software is customarily provided to the public. Accordingly, Keysight provides the Software to U.S. government customers under its standard commercial license, which is embodied in its End User License Agreement (EULA), a copy of which can be found at http://www.keysight.com/find/

sweula. The license set forth in the

EULA represents the exclusive authority by which the U.S. government may use, modify, distribute, or disclose the Software. The EULA and the license set forth therein, does not require or permit, among other things, that Keysight: (1) Furnish technical information related to commercial computer software or commercial computer software documentation that is not customarily provided to the public; or (2) Relinquish to, or otherwise provide, the government rights in excess of these rights customarily provided to the public to use, modify, reproduce, release, perform, display, or disclose commercial computer software or commercial computer software documentation. No additional government requirements beyond those set forth in the EULA shall apply, except to the extent that those terms, rights, or licenses are explicitly required from all providers of commercial computer software pursuant to the FAR and the DFARS and are set forth specifically in writing elsewhere in the EULA. Keysight shall be under no obligation to update, revise or otherwise modify the Software. With respect to any technical data as defined by FAR 2.101, pursuant to FAR

12.211 and 27.404.2 and DFARS

227.7102, the U.S. government acquires no greater than Limited Rights as defined in FAR 27.401 or DFAR

227.7103-5 (c), as applicable in any technical data.

Warranty

THE MATERIAL CONTAINED IN THIS DOCUMENT IS PROVIDED “AS IS,” AND IS SUBJECT TO BEING CHANGED, WITHOUT NOTICE, IN FUTURE EDITIONS. FURTHER, TO THE MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW, KEYSIGHT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, WITH REGARD TO THIS MANUAL AND ANY INFORMATION CONTAINED HEREIN, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. KEYSIGHT SHALL NOT BE LIABLE FOR ERRORS OR FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES IN CONNECTION WITH THE FURNISHING, USE, OR PERFORMANCE OF THIS DOCUMENT OR OF ANY INFORMATION CONTAINED HEREIN. SHOULD KEYSIGHT AND THE USER HAVE A SEPARATE WRITTEN AGREEMENT WITH WARRANTY TERMS COVERING THE MATERIAL IN THIS DOCUMENT THAT CONFLICT WITH THESE TERMS, THE WARRANTY TERMS IN THE SEPARATE AGREEMENT SHALL CONTROL.

Safety Information

A CAUTION notice denotes a hazard. It calls attention to an operating procedure, practice, or the like that, if not correctly performed or adhered to, could result in damage to the product or loss of important data. Do not proceed beyond a CAUTION notice until the indicated conditions are fully understood and met.

A WARNING notice denotes a hazard. It calls attention to an operating procedure, practice, or the like that, if not correctly performed or adhered to, could result in personal injury or death. Do not proceed beyond a WARNING notice until the indicated conditions are fully understood and met.

2 Keysight 34921A-34925A User’s Guide

Safety Symbols

The following symbols on the instrument and in the documentation indicate precautions which must be taken to maintain safe operation of the instrument.

Alternating current (AC) Caution, risk of electric shock

Frame or chassis (ground) terminal

Standby supply. Unit is not completely disconnected from ac mains when switch is off

Caution, risk of danger (refer to this manual for specific Warning or Caution information)

Keysight 34921A-34925A User’s Guide 3

Additional Safety Notices

The following general safety precautions must be observed during all phases of operation of this instrument. Failure to comply with these precautions or with specific warnings or instructions elsewhere in this manual violates safety standards of design, manufacture, and intended use of the instrument. Keysight Technologies assumes no liability of the customer’s failure to comply with the requirements.

General

Do not use this products in any manner not specified by the manufacturer. The protective features of this product may be impaired if it is used in a manner not specified in the operation instructions.

Before Applying Power

Verify that all safety precautions are taken. Make all connections to the unit before applying power.

Ground the Instrument

This product is provided with protective earth terminals. To minimize shock hazard, the instrument must be connected to the ac power mains through a grounded power cable, with the ground wire firmly connected to an electrical ground (safety ground) at the power outlet. Any interruption of the protective (grounding) conductor or disconnection of the protective earth terminal will cause a potential shock hazard that could result in personal injury.

Do Not Operate in an Explosive Atmosphere

Do not operate the instrument in the presence of flammable gases or fumes.

4 Keysight 34921A-34925A User’s Guide

Do Not Remove the Instrument Cover

Only qualified, service-trained personal who are aware of the hazards involved should remove instrument covers. Always disconnect the power cable and any external circuits before removing the instrument cover.

Do Not Modify the Instrument

Do not install substitute parts or perform any unauthorized modification to the product. Return the product to an Keysight Sales and Service Office for service and repair to ensure that safety features are maintained.

In Case of Damage

Instruments that appear damaged or defective should be made inoperative and secured against unintended operation until they can be repaired by qualified service personnel.

Keysight 34921A-34925A User’s Guide 5

Waste Electrical and Electronic Equipment (WEEE) Directive 2002/ 96/EC

This instrument complies with the WEEE Directive (2002/96/EC) marking requirement. This affixed product label indicates that you must not discard this electrical or electronic product in domestic household waste.

Product category:

With reference to the equipment types in the WEEE directive Annex 1, this instrument is classified as a “Monitoring and Control Instrument” product.

The affixed product label is as shown below.

Do not dispose in domestic household waste.

To return this unwanted instrument, contact your nearest Keysight Service Center, or visit http://about.keysight.com/en/companyinfo/environment/takeback.shtml for more information.

Sales and Technical Support

To contact Keysight for sales and technical support, refer to the support links on the following Keysight websites:

– www.keysight.com/find/34980a

(product-specific information and support, software and documentation updates)

– www.keysight.com/find/assist

(worldwide contact information for repair and service)

6 Keysight 34921A-34925A User’s Guide

See the Introduction to the Plug In Modules chapter of the 34980A Mainframe User’s Guide for detailed environmental operating conditions for the 34980A mainframe and its installed modules. That guidance sets maximum per channel current ratings at rated voltage for pollution degree 1 (dry) and pollution degree 2 (possible condensation) conditions, for all of the multiplexer modules.

Safety Interlock

The Analog Buses of the 34980A are capable of carrying 300V signals. The MUX modules have a hardware Safety Interlock feature that automatically opens the Analog Bus relays when the associated interlock pins on the D-sub connectors (faceplate) lose continuity. This prevents signals on the Analog Buses from being present on the D-sub connector pins. Optional terminal blocks available from Keysight automatically provide continuity for these interlock pins. If cables are used, you must provide continuity for the interlock pins in your DUT assembly. See the pinout information later in this guide for the location of interlock pins on each module.

The MUX modules have Analog Bus relays on each of their two banks. Therefore, the interlock pins are present on both the Bank 1 and Bank 2 D-sub connectors on the MUX modules.

Normally, if you attempt to connect to the Analog Buses without a terminal block or cable connected, an error is generated. The SYSTem:ABUS:INTerlock:SIMulate command allows you to temporarily disable errors generated by the Safety Interlock feature and enables the simulation mode. Although Safety Interlock errors are suppressed in this mode, the actual Analog Bus relays affected by the Safety Interlock are disabled as long as no terminal block or cable is connected to the module.

The Safety Interlock feature is implemented in hard ware on the modules and cannot be circumvented. Regardless of whether the simulation mode is enabled or disabled, all Analog Bus connections are prohibited as long as no terminal block or properly-wired cable is connected to the module.

Keysight 34921A-34925A User’s Guide 11

– The simulation mode applies to the entire mainframe and cannot be selectively

used on individual modules.

– When the simulation mode is enabled, the Analog Bus relays will appear to

close and open as directed. For example, no errors are generated if you close an Analog Bus relay from the front panel, remote interface, or Web Interface. However, remember that the Safety Interlock feature prevents the actual hardware state of the Analog Bus relays from being changed. When you connect a terminal block or cable to the module, the Analog Bus relays will be closed.

– The simulation setting is stored in volatile memory and will be lost when power

is turned off. To re-enable the simulation mode after power has been off, you must send the command again.

12 Keysight 34921A-34925A User’s Guide

SCPI Programming Examples for the Multiplexer Modules

The programming examples below provide you with SCPI command examples to use for actions specific to the MUX modules.

The slot and channel addressing scheme used in these examples follow the form sccc where s is the mainframe slot number (1 through 8) and ccc is the three-digit channel number. For information on specific MUX channel configurations, refer to the simplified schematics contained in each MUX section of this manual.

For complete information on the SCPI commands used to program the 34980A, with example programs, refer to the Keysight 34980A Programmer’s Reference which can be downloaded from www.keysight.com/find/34980A.

Opening and Closing Channels

Example: Closing and opening channels on the armature and reed MUX modules

channel in a bank is defined to be part of the scan list, and a scan is occurring, attempting to close another channel (including Analog Bus channels) within the same bank will result in an error. Channel closures in the other bank are allowed as long as no channels are part of the scan list.

The following commands close and open channels 13 and 15 through 18 in slot 3.

ROUTe:CLOSe (@3013,3015:3018) ROUTe:OPEN (@3013,3015:3018)

This command closes the specified channels on a MUX module. If any

Example: Closing channels on the FET MUX mod ule

supports a 1:N type closure, meaning that you can have only one channel per bank closed at a time. The following command closes then automatically opens each channel from 1-19 (Bank 1) in succession, leaving channel 20 closed. Then the command continues closing and opening channels 21 to 39 (Bank 2), then leaving channel 40 closed. At the end, only channels 20 and 40 will be closed, while all other channels will have been closed and then opened. In this process, a channel will open before the next channel in succession closes, making this a “break-before-make” series.

ROUTe:CLOSe (@3001:3040)

The following command opens the closed channel on Bank 1 of a FET MUX module in slot 3, and closes channel 15 on that bank.

ROUTe:CLOSe (@3015)

Keysight 34921A-34925A User’s Guide 13

The FET MUX module

Example: Closing and opening Analog Bus relays

connects the Analog Buses to Bank 1 (via the Analog Bus relays on Bank 1) for a module in slot 3.

ROUTe:CLOSe (@3911,3912,3913,3914) ROUTe:OPEN (@3911,3912,3913,3914)

The Analog Bus relays (numbered s911, s912, s913, etc.) on the MUX modules are ignored if they are included in a range of channels. An error will be generated if an Analog Bus relay is specified as the first or last channel in a range of channels. For example, the following command closes all valid channels between channel 30 (slot 1) and channel 5 (slot 2). In addition, this command closes Analog Bus relay 911 on the module in slot 1 (Bank 1). Note that although the specified range of channels includes the other Analog Bus relays, they are ignored and are not closed by this command.

ROUTe:CLOSe (@1030:2005,1911)

The following command

Example: Querying channels for open or close state

command returns a 1 (true) or 0 (false) state of channel 036 for a module in slot 3.

ROUTe:CLOSe (@3036) ROUTe:CLOSe? (@3036) !Returns a 1 ROUTe:OPEN? (@3036) !Returns a 0

The following

Making Measurements

Example: Making voltage measurements

configures channels 9 and 10 in slot 4 for DC voltage measurements, triggers the internal DMM to scan channels 9 and 10, and returns the reading. The 1 V range is selected with 1 mV resolution.

MEASure:VOLTage:DC? 1,0.001, (@4009,4010)

Example: Making voltage measurements using INITiate and FETCh?

The following program segment shows how to use the INITiate command with the CONFigure and FETCh? commands. The ROUTe:SCAN command puts channels 3 and 8 (of a module in slot 1) into the scan list (and redefines the scan list). The INITiate command scans the specified channels, and then sends the readings to memory. The FETCh? command transfers the readings from memory to the user.

The following command

14 Keysight 34921A-34925A User’s Guide

CONFigure:VOLTage:DC 10,0.003,(@1003,1008)

NOTE

ROUTe:SCAN (@1003,1008) INITiate FETCh?

Example: Making current measurements

channel 43 for a 34921A modules in slot 7 for dc current measurements, triggers the internal DMM to scan the channel, and then sends the reading to the output buffer of the 34980A. The default settings for range (autorange) and resolution (1 PLC) are used for the measurement.

MEASure:CURRent:DC? (@7043)

The following command configures

Configuring a Module

Example: Configuring a module for 2-wire or 1-wire mode

command configures a MUX module in slot 4 for 1-wire mode. Because you can configure only the 34923A and 34925A MUX modules (and the 34933A matrix module) for either 2-wire or 1-wire mode, an error is generated if you send this command to a slot that does not contain one of those three modules. If you are using terminal blocks with these modules, be sure to use the corresponding 2-wire or 1-wire terminal block.

SYSTem:MODule:WIRE:MODE WIRE1,4

When using a command to configure the system, the new configuration does not take effect until you cycle power on the 34980A.

Example: Querying the system for module Identify

returns the identity of the module installed in slot 7.

The following command

The following

SYSTem:CTYPe? 7

For the 34923A and the 34925A MUX modules, the query response may include a suffix to indicate a 1-wire configuration. For example, the response for the 34923A will be either "34923A" (differential mode) or "34923A-1W" (single-ended mode).

Keysight 34921A-34925A User’s Guide 15

Querying and Clearing Cycle Count, and Resetting Modules

NOTE

Example: Querying the cycle count for a relay

returns the cycle count on channel 7 and channel 16 for a MUX module in slot 1.

DIAGnostic:RELay:CYCLes? (@1007,1016)

The 34925A will return 0 for relay counts because the FET relays on that module are non-mechanical and have an undefined lifetime.

Example: Clearing the cycle count for a relay

the cycle count to zero on the channels 7 and 16 for a MUX module in slot 1.

DIAGnostic:RELay:CYCLes:CLEar (@1007,1016)

Example: Resetting module(s) to power-on state

resets a module in slot 4 to its power-on state.

SYSTem:CPON 4

The following command

The following command resets

The following command

16 Keysight 34921A-34925A User’s Guide

34921A 40-Channel Armature Multiplexer with Low Thermal Offset

NOTE

The 34921A 40-Channel Armature Multiplexer (40-Ch Arm MUX) is divided into two banks with 20 latching armature switches (channels 1-20 and 21-40) in each. This module also offers four additional fused relays (channels 41-44) for making AC and DC current measurements with the internal DMM with no external shunts needed. These current channels feature “make-before-break” connections to ensure continuous current flow when switching from one current channel to another. The current fuses are replaceable. Refer to the 34980A Service Guide for specific information about these fuses.

This module also contains nine armature Analog Bus relays (channels 911-914, 921-924, and 931), four on each bank that can connect the bank relays to the system Analog Buses and one that connects the current relays to the current input of the DMM. Through ABus1 and ABus2 you can connect any of the channels to the internal DMM for voltage or resistance measurements. Refer to the simplified schematic on page 19.

ABus1 consists of three wires that are used for current and voltage measurements. A separate current bus on ABus1 connects to the internal DMM current measurement input and this bus can be connected only to channels 41 through 44. The current channel low (L) signal path is common with the ABus1 low (L) signal path. You cannot measure current and voltage on ABus1 simultaneously.

Using program commands or the mainframe front panel, you can control each of the channel switches individually, and thus configure the 34921A module in these modes:

– two independent 20-channel 2-wire MUXes. This configuration requires

neither using external wiring nor connecting through the internal Analog Buses.

– one 20-channel 4-wire MUX. This configuration requires neither using external

wiring nor connecting through the internal Analog Buses. For 4-wire resistance measurements, the instrument automatically pairs channel n on Bank 1 (source) with channel n+20 on Bank 2 (sense) to provide these connections. Four-wire controls occur only when doing 4-wire measurement operations through the internal DMM, such as MEASure:FRESistance? or scanning a channel previously configured as 4-wire.

Keysight 34921A-34925A User’s Guide 17

– one 40-channel 2-wire MUX. You must use external wiring or connect through

the internal Analog Bus relays for this configuration. For example, closing Analog Bus channels 913 and 923 connects Bank 1 and Bank 2 through ABus3. Or, externally you can connect COM1 to COM2 to create this configuration.

Low thermal offset voltage makes the 34921A ideal for low-level signal switching. The 34921T optional terminal block provides a built-in thermocouple reference junction that helps minimize errors due to thermal offset when you measure thermocouples.

This module has capability to scan as many as 100 channels/second using the internal DMM. With the automatic “break-before-make” connection operation, you are assured that no two signals are connected to each other during a scan. When using the module in a non-scanning mode, you can close as many channels as you wish.

This module is safety interlock protected, which means whenever the D-sub connector end of the modules is exposed, the Analog Bus relays automatically open and disconnect from the Analog Bus. For more information, see “Safety

Interlock” on page 11 and “34921A D-Sub Connectors” on page 20.

When power is off, all channel relays maintain state, and the Analog Bus relays open.

18 Keysight 34921A-34925A User’s Guide

34921A Simplified Schematic

026

027

028

029

030

ABus 2

DMM

(SENS)

ABus3

ABus 4

931

923

913 914

924

922

912911

921

DMM

(MEAS)

L

001

002

003

004

005

H

L

006

007

008

009

010

H

L

011

012

013

014

015

L

H

016

017

018

019

020

021

022

023

024

025

H

L

031

032

033

034

035

036

037

038

039

040

L

H

L

H

L

Current

Fuse

0

42

0

43

0

41

LH

LHLH

LH

H

L

0

44

LH

H

LH

COM 2

Bank 2

Current

Bank 1

COM 1

Analog Buses

I

ABus 1

NOTE: The three-digit number assigned to each switch represents the channel number.

NOTE: Bank Relays: Armature latching Analog Bus Relays: Armature non-latching

This drawing shows two independent 20-channel 2-wire MUXes.

Keysight 34921A-34925A User’s Guide 19

34921A D-Sub Connectors

For orientation, the D-sub connector end of the module is facing you.

Bank 2

Bank 1

17L

34

35

36 37

38

39 40

41

42

43 44 45

46

47 48 49

50

18

19 20

21 22

23

24

25 26

27 28

29 30 31 32

33

1 2 3 4 5 6 7 8 9 1011121314151617

TSIL* 11H 11L 7H 7L 17H 13H 13L 9H 9L 19H 19L 15H 15L Interlock 1

Interlock11H 1L 2H 2L 3H 3L

COM1HCOM

1L

4H 4L 14H 14L 5H 5L 20H 20L

18HGND 6H 6L 16H 16L 12H 12L 8H 8L 18L 10H 10L

AMP

41L

AMP

41I

AMP

42L

AMP

42I

*TSIL = Temperature Sensor Interface Line. Provides thermocouple reference sensor serial output line to the mainframe processor.

50-Pin D-Sub Male Connector

WARNING

Bank 1

Description Pin Description Pin Description Pin Description Pin Description Pin

1H 1 6H 35 11H 19 16H 37 COM1 H 7

1L 2 6L 36 11L 20 16L 38 COM1 L 8

2H 3 7H 21 12H 39 17H 23 Interlock 1 17

2L 4 7L 22 12L 40 17L 24 Interlock 1 33

3H 5 8H 41 13H 25 18H 43 GND 34

3L 6 8L 42 13L 26 18L 44 TSIL* 18

4H 9 9H 27 14H 11 19H 29 AMP 41L 47

4L 10 9L 28 14L 12 19L 30 AMP 41I 48

5H 13 10H 45 15H 31 20H 15 AMP 42L 49

5L 14 10L 46 15L 32 20L 16 AMP 42I 50

As a safety feature, interlock 1 pins (17 and 33) on Bank 1 must be shorted to enable the Bank 1 Analog Bus relays to close. The optional 34921T terminal block shorts these pins for you. This feature protects inadvertent routing of high voltages from the Analog Bus to the D-sub connector of the module.

20 Keysight 34921A-34925A User’s Guide

Bank 2

34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

23L Interlock 221H 21L 22H 22L 23H

COM2HCOM

2L

24H 24L 34H 34L 25H 25L 40H 40L

1234567891011121314151617

37LTSIL* 31H 31L 27H 27L 37H 33H 33L 29H 29L 39H 39L 35H 35L Interlock 2

18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33

GND 26H 26L 36H 36L 32H 32L 28H 28L 38H 38L 30H 30L

AMP

43L

AMP

43I

AMP

44L

AMP

44I

50-Pin D-Sub Male Connector

*TSIL = Temperature Sensor Interface Line. Provides thermocouple reference sensor serial output line to the mainframe processor.

WARNING

Description Pin Description Pin Description Pin Description Pin Description Pin

21H 1 26H 35 31H 19 36H 37 COM2 H 7

21L 2 26L 36 31L 20 36L 38 COM2 L 8

22H 3 27H 21 32H 39 37H 23 Interlock 2 17

22L 4 27L 22 32L 40 37L 24 Interlock 2 33

23H 5 28H 41 33H 25 38H 43 GND 34

23L 6 28L 42 33L 26 38L 44 TSIL* 18

24H 9 29H 27 34H 11 39H 29 AMP 43L 47

24L 10 29L 28 34L 12 39L 30 AMP 43I 48

25H 13 30H 45 35H 31 40H 15 AMP 44L 49

25L 14 30L 46 35L 32 40L 16 AMP 44I 50

As a safety feature, interlock 2 pins (17 and 33) on Bank 2 must be shorted to enable the Bank 2 Analog Bus relays to close. The optional 34921T terminal block shorts these pins for you. This feature protects inadvertent routing of high voltages from the Analog Bus to the D-sub connector of the module.

Keysight 34921A-34925A User’s Guide 21

34921T Terminal Block

NOTE

Temperature

Sensor

34921T (viewed from bottom side)

External Reference

This terminal block with screw-type connections is labeled with the model number and the abbreviated module name. In addition, space is available on the label for you to write the slot number.

All modules that connect to the internal DMM are interlock protected. This means that when an installed module is exposed (no terminal block or cable is connected), the Analog Bus relays are open and disconnected from the Analog Buses. See “Safety Interlock” on page 11 for further information.

The 34921T is the only terminal block that provides an isothermal block with temperature reference for thermocouple measurements. The temperature sensor is located on the bottom side of the PC board as shown below. Also shown are two holes that you can use for connecting an external temperature reference to the terminal block.

22 Keysight 34921A-34925A User’s Guide

CAUTION

When wiring the terminal block via cables to the mainframe, make sure the

W

i

r

e

S

i

z

e

:

2

0

A

W

G

T

y

p

i

c

a

l

1

8

A

W

G

M

a

x

cables are connected to the correct connector. The cables provide communication and power to the temperature sensor on the 34921T terminal block. If cabling is not correct, an error may occur indicating that the 34921A module is not fully operational.

Keysight 34921A-34925A User’s Guide 23

34922A 70-Channel Armature Multiplexer

The high-density 34922A 70-Channel Armature Multiplexer (70-Ch Arm MUX) is divided into two banks with 35 latching armature switches (channels 1-35 and 36-70) in each. This module also contains eight armature Analog Bus relays (channels 911-914 and 921-924), four on each bank that can connect the bank relays to the system Analog Buses. Through ABus1 and ABus2 you can connect any of the channels to the internal DMM for voltage or resistance measurements. Refer to the simplified schematic on page 25.

Using program commands or the mainframe front panel, you can control each of the channel switches individually, and thus configure the 34922A in these modes:

– two independent 35-channel 2-wire MUXes. This configuration requires

neither using external wiring nor connecting through the internal Analog Buses.

– one 35-channel 4-wire MUX. This configuration requires neither using external

wiring nor connecting through the internal Analog Buses. For 4-wire resistance measurements, the instrument automatically pairs channel n on Bank 1 (source) with channel n+35 on Bank 2 (sense) to provide these connections. Four-wire controls occur only when doing 4-wire measurement operations through the internal DMM, such as MEASure:FRESistance? or scanning a channel previously configured as 4-wire.

– one 70-channel 2-wire MUX. You must use external wiring or connect through

the internal Analog Bus relays for this configuration. For example, closing Analog Bus channels 913 and 923 connects Bank 1 and Bank 2 through ABus3. Or, externally you can connect COM1 to COM2 to create this configuration.

This module has capability to scan as many as 100 channels/second using the internal DMM. With the automatic “break-before-make” connection operation, you are assured that no two signals are connected to each other during a scan. When using the module in a non-scanning mode, you can close as many channels as you wish.

This module is interlock protected, which means whenever the D-sub connector end of the modules is exposed, the Analog Bus relays automatically open and disconnect from the Analog Bus. For more information, see “Safety Interlock” on page 11 and “34922A D-Sub Connectors” on page 26.

When the power is off, all channel relays maintain state, and the Analog Bus relays open.

24 Keysight 34921A-34925A User’s Guide

34922A Simplified Schematic

LH

ABus2 DMM (SENS)

ABus3 ABus4

ABus1 DMM (MEAS)

001

002

003

004

005

H

L

006

007

HL

H

015

016

017

018

019

L

020

021

022

023

024

025

026

H

L

027

028

029

030

031

032

033

H

L

034

035

008

009

010

011

012

H

L

013

014

036

037

038

039

040

041

042

H

L

043

044

045

046

047

048

049

H

L

H

L

050

051

052

053

054

055

056

057

058

059

060

061

062

063

H

L

064

065

066

067

068

069

070

H

L

911

924

914913

923

912

921 922

LH

LHLHLHLH

LHLH

HL

Bank 1

Bank 2

COM 1

COM 2

Analog Buses

NOTE: Bank Relays: Armature latching Analog Bus Relays: Armature non-latching

NOTE: The three-digit number assigned to each switch represents the channel number.

This drawing shows two independent 35-channel 2-wire MUXes.

Keysight 34921A-34925A User’s Guide 25

34922A D-Sub Connectors

For orientation, the D-sub connector end of the module is facing you.

Bank 2

Bank 1

10H6H 6L 1H 1L 7H 7L

COM

1L 3H 3L 9H 9L 4H 4L

COM

1H2H 2L 10L 5L5H

1 2 3 4 5 6 7 8 9 1011121314151617

18

19

20

12H16H 16L 11H 11L 17H 17L 12L 8H 8 L 34H 34L 19H 19L 14H 14L 20H 20L Interlock1

21

22 23

24 25

26

27

28 29

30 31

32 33 34 35

36

37

38 39

GND 26H 26L 21H 21L 22H 22L 27H 27L 13H 13L 28H 28L 24H 24L 29H 29L 1 5H 15L Interlock 1

40

41

42 43

44

45 46

47

48

49 50 51

52

53 54 55

56

57 5958

60

61 62

63 64

65

66

67 68

69 70

71 72 73 74

75

76

77 78

GND 32H 3 2L 31H 31L 33H 33L 18H 18L 23H 23L 35H 35L 30H 30L 25H 25L

NC NC

78-Pin D-Sub Male Connector

Bank 1

Description Pin Description Pin Description Pin Description Pin Description Pin Description Pin

1H 3 8H 29 15H 57 22H 45 29H 55 COM1 H 9

1L 4 8L 30 15L 58 22L 46 29L 56 COM1 L 10

2H 7 9H 13 16H 21 23H 69 30H 73 Interlock 1 39

2L 8 9L 14 16L 22 23L 70 30L 74 Interlock 1 59

3H 11 10H 17 17H 25 24H 53 31H 63 GND 40

3L 12 10L 18 17L 26 24L 54 31L 64 GND 60

4H 15 11H 23 18H 67 25H 75 32H 61 No Connect 77

4L 16 11L 24 18L 68 25L 76 32L 62 No Connect 78

5H 19 12H 27 19H 33 26H 41 33H 65

5L 20 12L 28 19L 34 26L 42 33L 66

6H 1 13H 49 20H 37 27H 47 34H 31

6L 2 13L 50 20L 38 27L 48 34L 32

7H 5 14H 35 21H 43 28H 51 35H 71

7L 6 14L 36 21L 44 28L 52 35L 72

26 Keysight 34921A-34925A User’s Guide

WARNING

As a safety feature, interlock 1 pins (39 and 59) on Bank 1 must be shorted to

For orientation, the D-sub connector end of the module is facing you.

Bank 2

Bank 1

45H41H 41L 36H 36L 42H 42L

COM

2L 38H 38L 44H 44L 39H 39L

COM

2H37H 37L 45L 40L40H

1 2 3 4 5 6 7 8 9 1011121314151617

18

19

20

47H51H 51L 46H 46L 52H 52L 47L 43H 43L 69H 69L 54H 54L 49H 49L 55H 55L Interlock 2

21

22 23

24 25

26

27

28 2 9

30 31

32 33 34 35

36

37

38 39

GND 61H 61L 56H 56L 57H 57L 62H 62L 48H 48L 63H 63L 59H 59L 64H 64L 50H 50L Interlock 2

40

41

42 43

44

45 46

47

48

49 50 51

52

53 54 55

56

57 5958

60

61 62

63 64

65

66

67 6 8

69 70

71 72 73 74

75

76

77 78

GND 67H 67L 66H 66L 68H 68L 53H 53L 58H 58L 70H 70L 65H 65L 60H 60L

NC NC

78-Pin D-Sub Male Connector

enable the Bank 1 Analog Bus relays to close. The optional 34922T terminal blocks short these pins for you. This feature protects inadvertent routing of high voltages from the Analog Buses to the D-sub connector of the module.

Bank 2

Description Pin Description Pin Description Pin Description Pin Description Pin Description Pin

36H 3 43H 29 50H 57 57H 45 64H 55 COM2 H 9

36L 4 43L 30 50L 58 57L 46 64L 56 COM2 L 10

37H 7 44H 13 51H 21 58H 69 65H 73 Interlock 2 39

37L 8 44L 14 51L 22 58L 70 65L 74 Interlock 2 59

38H 11 45H 17 52H 25 59H 53 66H 63 GND 40

38L 12 45L 18 52L 26 59L 54 66L 64 GND 60

39H 15 46H 23 53H 67 60H 75 67H 61 No Connect 77

39L 16 46L 24 53L 68 60L 76 67L 62 No Connect 78

40H 19 47H 27 54H 33 61H 41 68H 65

40L 20 47L 28 54L 34 61L 42 68L 66

Keysight 34921A-34925A User’s Guide 27

Description Pin Description Pin Description Pin Description Pin Description Pin Description Pin

WARNING

NOTE

41H 1 48H 49 55H 37 62H 47 69H 31

41L 2 48L 50 55L 38 62L 48 69L 32

42H 5 49H 35 56H 43 63H 51 70H 71

42L 6 49L 36 56L 44 63L 52 70L 72

As a safety feature, interlock 2 pins (39 and 59) on Bank 2 must be shorted to enable the Bank 2 Analog Bus relays to close. the optional 34922T terminal blocks short these pins for you. This feature protects inadvertent routing of high voltages from the Analog Buses to the D-sub connector of the module.

34922T Terminal Blocks

Two terminal blocks are available to facilitate wiring connections to the 34922A module:

34922T-001 (Option 001) Terminal block with solder connectors

34922T-002 (Option 002) Terminal block with screw connectors

All modules that connect to the internal DMM are interlock protected. This means that when an installed module is exposed (no terminal block or cable is connected), the Analog Bus relays are open and disconnected from the Analog Buses. See “Safety Interlock” on page 11 for further information.

28 Keysight 34921A-34925A User’s Guide

34922T-001 Terminal Block

W

i

r

e

S

i

z

e

:

2

A

W

G

T

y

p

i

c

a

l

2

0

A

W

G

M

a

x

This terminal block with solder-type connections is labeled with the model number and the abbreviated module name. In addition, space is available on the label for you to write the slot number.

Keysight 34921A-34925A User’s Guide 29

34922T-002 Terminal Block

B A N K

1

B

A

N

K

2

1

2

3 4 5 COM1

6

7

8 9 10 11

HLHLHLHLHLH

L

HLHLHLHL

HLHL

12

13

14 15 16

17

HLHLHLHL

HLHL

HLHLHLHLHLH

L

18

19

20 21 22 23

24

25

26 27 28

29

HLHLHLHL

HLHL

HLHLHLHLHLH

L

30

31

32 33 34 35

59

60

61 62 63 64

HLHLHLHLHLH

L

HLHLHLHL

HLHL

65

66

67 68 69

70

47

48

49 50 51 52

HLHLHLHLHLH

L

HLHLHLHL

HLHL

53

54

55 56 57

58

COM2

36

37 38 39

40

HLHLHLHL

HLHL

HLHLHLHLHLH

L

41

42

43 44 45 46

W

i

r

e

S

i

z

e

:

2

0

A

W

G

T

y

p

i

c

a

l

1

8

A

W

G

M

a

x

This terminal block with screw-type connections is labeled with the model number and the abbreviated module name. In addition, space is available on the label for you to write the slot number.

30 Keysight 34921A-34925A User’s Guide

34923A 40/80-Channel Reed Multiplexer

NOTE

The 34923A 40/80-Channel Reed Multiplexer (40/80-Ch Reed MUX) is divided into two equal banks of non-latching reed switches. This module also contains eight armature Analog Bus relays (channels 911-914 and 921-924), four on each bank that can connect the bank relays to the system Analog Buses. You can connect any of the channels to the internal DMM through ABus1 and ABus2 for voltage or resistance measurements.

Using program commands or the mainframe front panel, you can control each of the channel switches individually, and configure this module for differential (2-wire or 4-wire) or single-ended (1-wire) mode. Refer to the simplified schematics on page 34 and page 38.

If you are using an Keysight 34923T-00x terminal block to connect your DUT to this module, be sure to use the terminal block that corresponds to your module configuration mode (Refer to the terminal block drawings on page 37 and page 41.):

34923T-001 (Option 001) Terminal block for differential (two- or four-wire) mode

34923T-002 (Option 002) Terminal block for single-ended (1-wire) mode

You can confirm the mode in which your module is configured by using the SYSTem:CTYPe? <slot number> program command. This command returns the identity of the plug-in module in the specified slot.

Whenever you change from 2- or 4-wire mode to 1-wire mode, or the reverse, you must cycle power on the 34980A for the configuration to take effect.

In all modes, this module has capability to scan as many as 500 channels/second using the internal DMM. With the automatic “break-before-make” connection operation, you are assured that no two signals are connected to each other during a scan.

This module is interlock protected, which means whenever the D-sub connector end of the modules is exposed, the Analog Bus relays immediately open and disconnect from the Analog Bus. For more information, see “Safety Interlock” on page 11 and the D-Sub connector drawings on page 35 and page 39.

Keysight 34921A-34925A User’s Guide 31

CAUTION

Because user-attached reactive loads and backplane parasitic capacitance may result in high in-rush currents, 100 relays from damage and performance degradation. Therefore, you must consider these resistors when you are designing a measurement. Refer to the simplified schematics on page 34 and page 38.

Lifetime of relays is severely degraded as current or voltage goes up. If higher voltage is being switched, limits on source current are recommended.

When the power is off, all channel and Analog Bus relays open.

Two-Wire Mode

You may configure the 34923A as:

– two independent 20-channel 2-wire MUXes. This configuration requires

neither the use of external wiring nor connection through the internal Analog Buses.

– one 40-channel, 2-wire MUX. For this configuration, you must use external

wiring or connect through the internal Analog Buses.

In 2-wire mode, you can close no more than 20 channels simultaneously due to power dissipation. These 20 channels are split 10 to a bank. However, note that Analog Bus relays count half as much as channel relays in that total. For example, with one Analog Bus relay closed, you can close up to a maximum of 19 channel relays. If you try to close more than the allowed number of channels, you will receive an error message.

Ω

in-rush resistors protect the reed

Four-Wire Mode

You may configure the 34923A as a 20-channel 4-wire MUX. This configuration requires neither external wiring nor connection through the Analog Buses.

For 4-wire resistance measurements, the instrument automatically pairs channel n on Bank 1 (source) with channel n+20 on Bank 2 (sense) to provide these connections. Four-wire controls occur only when doing 4-wire measurement operations through the internal DMM, such as MEASure:FRESistance? or scanning a channel previously configured as 4-wire.

32 Keysight 34921A-34925A User’s Guide

One-Wire Mode

NOTE

You may configure the 34923A as:

– two independent 40-channel 1-wire MUXes. This configuration requires

neither external wiring nor connection through the internal Analog Buses.

– one 80-channel 1-wire MUX. You must use external wiring or connect through

the internal Analog Bus for this configuration.

Because all bank relays supply only HI signals, you can apply a LOW signal through COM1 L or COM2 L when you are making 2-wire resistance measurements in 1-wire mode.

In 1-wire mode, you can close no more than 40 channels simultaneously due to power dissipation. These channels are split 20 to a bank. For example, with one Analog Bus relay closed you can close up to a maximum of 39 channel relays. If you try to close more than the allowed number of channels, you will receive an error message.

Keysight 34921A-34925A User’s Guide 33

34923A Simplified Schematic for Two- or Four-Wire Mode

HL

026

027

028

029

030

031

032

033

034

035

036

037

038

039

040

021

022

023

024

025

001

002

003

004

005

006

007

008

009

010

011

012

013

014

015

016

017

018

019

020

H

L

H

L

H

L

H

L

ABus 2 DMM (SENS)

ABus 3

ABus 4

923

913 914

924922

912911

921

ABus1 DMM (MEAS)

HL HL H L H L

L

H

L

H

L

H

L

H

L

HL

L

H

LHLHLHLH

HL

HL H L

H

LH

100Ω 100Ω

100Ω

100Ω 100Ω

Bank 1

Bank 2

COM 1

COM 2

Analog Buses

NOTE: The three-digit number assigned to each switch represents the channel number.

NOTE: Bank Relays: Reed non-latching Analog Bus Relays: Armature non-latching

This drawing shows two independent 20-channel 2-wire MUXes. To change configuration modes, use the SYSTem:MODule:WIRE:MODE command.

34 Keysight 34921A-34925A User’s Guide

34923A D-Sub Connectors for Two- or Four-Wire Mode

For orientation, the D-sub connector end of the module is facing you.

Bank 2

Bank 1

17L

18

19 20

21 22

23

24

25 26

27 28

29 30 31 32

33

Reserved 11H 11L 7H 7L 17H 13H 13L 9H 9L 19H 19L 15H 15L Int erlock 1

1 2 3 4 5 6 7 8 9 1011 1213141516 17

Interlock11H 1L 2H 2L 3H 3L

COM1HCOM

1L

4H 4L 14H 14L 5H 5L 20H 20L

GND 6H 6L 16H 16L 12H 12L 8H 8L 18H 18L 10H 10L

Reserved

34

35

36 37

38

39 40

41

42

43 44 45

46

47 48 49

50

50-Pin D-Sub Male Connector

Bank 1

Description Pin Description Pin Description Pin Description Pin Description Pin

1H 1 6H 35 11H 19 16H 37 COM1 H 7

1L 2 6L 36 11L 20 16L 38 COM1 L 8

2H 3 7H 21 12H 39 17H 23 Interlock 1 17

2L 4 7L 22 12L 40 17L 24 Interlock 1 33

3H 5 8H 41 13H 25 18H 43 GND 34

3L 6 8L 42 13L 26 18L 44 Reserved 18

4H 9 9H 27 14H 11 19H 29 Reserved 47

4L 10 9L 28 14L 12 19L 30 Reserved 48

5H 13 10H 45 15H 31 20H 15 Reserved 49

5L 14 10L 46 15L 32 20L 16 Reserved 50

Keysight 34921A-34925A User’s Guide 35

WARNING

As a safety feature, interlock 1 pins (17 and 33) on Bank 1 must be shorted to

37L

18 19

20

21

22

23 24 25 26 27 2 8 29 30 31 32 33

Reserved 31H 31L 27H 27L 37H 33H 33L 29H 29L 39H 39L 35H 35L Interlock 2

1234567891011121314151617

23L Interloc k 221H 21L 22H 22L 23H

COM2HCOM

2L

24H 24L 34H 34L 25H 25L 40H 40L

Reserved

34 35 36 37 38 39 40 41 42 43 44 45 46

47

48 49 50

GND 26H 26L 36H 36L 32H 32L 28H 28L 38H 38L 30H 30L

50-Pin D-Sub

Male Connector

WARNING

enable the Bank 1 Analog Bus relays to close. The optional 34923T-001 (for 2-wire) terminal block shorts these pins for you. This feature protects inadvertent routing of high voltages from the Analog Bus to the D-sub connector of the module.

Bank 2

Description Pin Description Pin Description Pin Description Pin Description Pin

21H 1 26H 35 31H 19 36H 37 COM2 H 7

21L 2 26L 36 31L 20 36L 38 COM2 L 8

22H 3 27H 21 32H 39 37H 23 Interlock 2 17

22L 4 27L 22 32L 40 37L 24 Interlock 2 33

23H 5 28H 41 33H 25 38H 43 GND 34

23L 6 28L 42 33L 26 38L 44 Reserved 18

24H 9 29H 27 34H 11 39H 29 Reserved 47

24L 10 29L 28 34L 12 39L 30 Reserved 48

25H 13 30H 45 35H 31 40H 15 Reserved 49

25L 14 30L 46 35L 32 40L 16 Reserved 50

As a safety feature, interlock 2 pins (17 and 33) on Bank 2 must be shorted to enable the Bank 2 Analog Bus relays to close. The optional 34923T-001 (for 2-wire) shorts these pins for you. This feature protects inadvertent routing of high voltages from the Analog Buses to the D-sub connector of the module.

36 Keysight 34921A-34925A User’s Guide

34923T-001 Terminal Block for Two-Wire or Four-Wire Mode

NOTE

W

i

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e

S

i

z

e

:

2

0

A

W

G

T

y

p

i

c

a

l

1

8

A

W

G

M

a

x

This terminal block with screw-type connections is labeled with the model number and the abbreviated module name. In addition, space is available on the label for you to write the slot number.

All modules that connect to the internal DMM are interlock protected. This means that when an installed module is exposed (no terminal block or cable is connected), the Analog Bus relays are open and disconnected from the Analog Buses. See “Safety Interlock” on page 11 for further information.

If you are using an Keysight terminal block to connect your DUT to this module be sure to use the 34923T-001 terminal block that corresponds to the 2- or 4-wire configuration mode. An error will not be generated if you have installed a terminal block that doesn't match the present module configuration.

Keysight 34921A-34925A User’s Guide 37

34923A Simplified Schematic for One-Wire Mode

ABus 2 DMM (SENS)

ABus3

ABus 4

ABus1 DMM (MEAS)

HH H H

021

022

023

024

025

026

027

028

029

030

011

012

013

014

015

016

017

018

019

020

031

032

033

034

035

036

037

038

039

040

001

002

003

004

005

006

007

008

009

010

911 912 913 914

921 922 923 924

HL

HL HLHL

HL

071

072

073

074

075

076

077

078

079

080

061

062

063

064

065

066

067

068

069

070

051

052

053

054

055

056

057

058

059

060

041

042

043

044

045

046

047

048

049

050

H

HL

HL HL HL HL

100Ω

100Ω 100Ω

100Ω

Bank 1

Bank 2

COM 1

COM 2

Analog Buses

NOTE: The three-digit number assigned to each switch represents the channel number.

NOTE: Bank relays: Reed non-latching Analog Bus relays: Armature non-latching

This drawing shows two independent 40-channel 1-wire MUXes. To change configuration modes, use the SYSTem:MODule:WIRE:MODE command.

38 Keysight 34921A-34925A User’s Guide

34923A D-Sub Connectors for One-Wire Mode

For orientation, the D-sub connector end of the module is facing you.

Bank 2Bank 1

34

35

36 37

38

39 40

41

42

43 44 45

46

47 48 49

50

18

19 20

21 22

23

24

25 26

27 28

29 30 31 32

33

GND11123132232415 1635361920

Reserv ed

Reserved 21 22 13 14 33 25 26 17 18 37 38 29 30 Interl ock 1

1 2 3 4 5 6 7 8 9 1011121314151617

Interlock1123456

COM

1H

COM

1L

7 8 27 28 9 10 39 40

50-Pin D-Sub Male Connector

Bank 1

Description Pin Description Pin Description Pin Description Pin Description Pin

1 1 11 35 21 19 31 37 COM1 H 7

2 2 12 36 22 20 31 38 COM1 L 8

3 3 13 21 23 39 33 23 Interlock 1 17

4 4 14 22 24 40 34 24 Interlock 1 33

5 5 15 41 25 25 35 43 GND 34

6 6 16 42 26 26 36 44 Reserved 18

7 9 17 27 27 11 37 29 Reserved 47

8 1018 2828 1238 30Reserved 48

9 1319 4529 3139 15Reserved 49

10 14 20 46 30 32 40 16 Reserved 50

Keysight 34921A-34925A User’s Guide 39

WARNING

As a safety feature, interlock 1 pins (17 and 33) on Bank 1 must be shorted to

74

34

35

36 37

38

39 4 0

41

42

43 44 45

46

47 48 49

50

18

19 20

21 22

23

24

25 26

27 28

29 30 31 32

33

GND515271726364555675 765960

Reserved 61 62 53 54 73 65 66 57 58 77 78 69 70 Inter lock 2

1 2 3 4 5 6 7 8 9 1011 1213 141516 17

Interlock 241 42 43 44 4 5 46

COM2HCOM

2L

47 48 67 68 49 50 79 80

Reser ved

50-Pin D-Sub Male Connector

WARNING

enable the Bank 1 Analog Bus relays to close. The optional 34923T-002 (for 1-wire) shorts these pins for you. This feature protects inadvertent routing of high voltages from the Analog Bus to the D-sub connector of the module.

Bank 2

Description Pin Description Pin Description Pin Description Pin Description Pin

411513561197137COM2 H7

422523662207238COM2 L 8

433532163397323Interlock 217

444542264407424Interlock 233

455554165257543GND34

466564266267644Reserved 18

479572767117729Reserved47

48 10 58 28 68 12 78 30 Reserved 48

49 13 59 45 69 31 79 15 Reserved 49

50 14 60 46 70 32 80 16 Reserved 50

As a safety feature, interlock 2 pins (17 and 33) on Bank 2 must be shorted to enable the Bank 2 Analog Bus relays to close. The optional 34923T-002 (for 1-wire) shorts these pins for you. This feature protects inadvertent routing of high voltages from the Analog Buses to the D-sub connector of the module.

40 Keysight 34921A-34925A User’s Guide

34923T-002 Terminal Block for One-Wire Mode

NOTE

W

i

r

e

S

i

z

e

:

2

0

A

W

G

T

y

p

i

c

a

l

1

8

A

W

G

M

a

x

This terminal block with screw-type connections is labeled with the model number and the abbreviated module name. In addition, space is available on the label for you to write the slot number.

All modules that connect to the internal DMM are interlock protected. This means that when an installed module is exposed (no terminal block or cable is connected), the Analog Bus relays are open and disconnected from the Analog Buses. See “Safety Interlock” on page 11 for further information.

If you are using an Keysight terminal block to connect your DUT to this module be sure to use the 34923T-002 terminal block that corresponds to the 1-wire configuration mode. An error will not be generated if you have installed a terminal block that doesn't match the present module configuration.

Keysight 34921A-34925A User’s Guide 41

34924A 70-Channel Reed Multiplexer

The high-density 34924A 70-Channel Reed Multiplexer (70-Ch Reed MUX) is divided into two banks with 35 non-latching reed switches (channels 1-35 and 36-70) in each. This module also contains eight armature Analog Bus relays (channels 911-914 and 921-924), four on each bank that can connect the bank relays to the system Analog Buses. Through ABus1 and ABus2 you can connect any of the channels to the system DMM for voltage or resistance measurements. See the simplified schematic on page 43.

Using program commands or the mainframe front panel, you can control each of the channel switches individually, and thus configure the 34924A in any of these modes:

– two independent 35-channel 2-wire MUXes. This configuration requires

neither using external wiring nor connecting through the internal Analog Buses.

– one 70-channel, 2-wire MUX. You must use external wiring or connect through

the internal Analog Buses for this configuration.

– one 35-channel 4-wire MUX. This configuration requires neither using external

wiring nor connecting through the internal Analog Buses. For 4-wire resistance measurements, the instrument automatically pairs channel n on Bank 1 (source) with channel n+35 on Bank 2 (sense) to provide these connections. Four-wire controls occur only when doing 4-wire measurement operations through the internal DMM, such as MEASure:FRESistance? or scanning a channel previously configured as 4-wire.

In 2-wire mode, you can close no more than 20 channels simultaneously due to power dissipation. These 20 channels are split 10 to a bank. However, note that Analog Bus relays count half as much as channel relays in that total. For example, with one Analog Bus relay closed, you can close up to a maximum of 19 channel relays. If you try to close more than the allowed number of channels, you will receive an error message.

In all modes, this module has capability to scan as many as 500 channels/second using the internal DMM. With the automatic “break-before-make” connection operation, you are assured that no two signals are connected to each other during a scan.

42 Keysight 34921A-34925A User’s Guide

CAUTION

Because user-attached reactive loads and backplane parasitic capacitance may result in high in-rush currents, 100 relays from damage and performance degradation. Therefore, you must consider these resistors when you are designing a measurement. Refer to the simplified schematic on page 43.

This module is interlock protected, which means whenever the D-sub connector end of the modules is exposed, the Analog Bus relays immediately open and disconnect from the Analog Bus. For more information, see “Safety Interlock” on page 11.

Lifetime of relays is severely degraded as current or voltage goes up. If higher voltage is being switched, limits on source current are recommended.

When the power is off, all channel and Analog Bus relays open.

34924A Simplified Schematic

Ω

in-rush resistors protect the reed

Keysight 34921A-34925A User’s Guide 43

This drawing shows two independent 35-channel 2-wire MUXes.

ABus2 DMM (SENS)

ABus3 ABus4

ABus1 DMM (MEAS)

911 914912 913

924922 923921

LH

001

002

003

004

005

H

L

006

H

015

016

017

018

019

L

020

021

022

023

024

025

026

H

L

027

028

029

030

031

032

033

H

L

034

008

009

010

011

012

H

L

013

007

035

014

H

L

036

037

038

039

040

041

042

H

L

043

044

045

046

047

048

049

H

L

050

051

052

053

054

055

056

063

H

L

064

065

066

067

068

069

070

057

058

059

060

061

062

H

L

LH

LHLH

LH

100Ω

100Ω 100Ω

100Ω

100Ω 100Ω

100Ω

Bank 1

Bank 2

COM 2

COM 1

Analog Buses

NOTE: The three-digit number assigned to each switch represents the channel number.

NOTE: Bank relays: Reed non-latching Analog Bus relays: Armature non-latching

44 Keysight 34921A-34925A User’s Guide

34924A D-Sub Connectors

For orientation, the D-sub connector end of the module is facing you.

Bank 2

Bank 1

10H6H 6L 1H 1L 7H 7L

COM

1L 3H 3L 9H 9L 4H 4L

COM

1H2H 2L 10L 5L5H

1 2 3 4 5 6 7 8 9 1011 12131415 16 17

18

19

20

12H16H 16H 11L 11H 17H 17L 12L 8H 8L 34H 34L 19H 19H 14H 14L 20H 20L Interlock1

21

22 23

24 25

26

27

28 29

30 31

32 33 34 35

36

37

38 39

GND 26H 26L 21H 21L 22H 22L 27H 27L 13H 13L 28H 28L 24L 24L 29H 29L 15H 15L Interlock 1

40

41

43

44

45 46

47

48

49 50 51

52

53 54 55

56

57 5958

60

61 62

63 64

65

66

67 68

69 70

71 72 73 74

75

76

77 78

GND 32H 32L 31H 31L 33H 33L 18H 18L 23H 23L 35H 35L 30H 30L 25H 25L

NC NC

42

78-Pin D-Sub Male Connector

Bank 1

Description Pin Description Pin Description Pin Description Pin Description Pin Description Pin

1H 3 8H 29 15H 57 22H 45 29H 55 COM1 H 9

1L 4 8L 30 15L 58 22L 46 29L 56 COM1 L 10

2H 7 9H 13 16H 21 23H 69 30H 73 Interlock 1 39

2L 8 9L 14 16L 22 23L 70 30L 74 Interlock 1 59

3H 11 10H 17 17H 25 24H 53 31H 63 GND 40

3L 12 10L 18 17L 26 24L 54 31L 64 GND 60

4H 15 11H 23 18H 67 25H 75 32H 61 No Connect 77

4L 16 11L 24 18L 68 25L 76 32L 62 No Connect 78

5H 19 12H 27 19H 33 26H 41 33H 65

5L 20 12L 28 19L 34 26L 42 33L 66

6H 1 13H 49 20H 37 27H 47 34H 31

6L 2 13L 50 20L 38 27L 48 34L 32

7H 5 14H 35 21H 43 28H 51 35H 71

7L 6 14L 36 21L 44 28L 52 35L 72

Keysight 34921A-34925A User’s Guide 45

WARNING

As a safety feature, interlock 1 pins (39 and 59) on Bank 1 must be shorted to

For orientation, the D-sub connector end of the module is facing you.

Bank 2

Bank 1

45H41H 41L 36H 36L 42H 42L

COM

2L 38H 38L 44H 44L 39H 39L

COM

2H37H 37L 45L 40L40H

1 2 3 4 5 6 7 8 9 1011 12131415 16 17

18

19

20

47H51H 51L 46H 46L 52H 52L 47L 43H 43L 69H 69L 54H 54L 49H 49L 55H 55L Interlock 2

21

22 23

24 25

26

27

28 29

30 31

32 33 34 35

36

37

38 39

GND 61H 61L 56H 56L 57H 57L 62H 62L 48H 48L 63H 63L 59H 59L 64H 64L 50H 50L Interlock 2

40

41

42 43

44

45 46

47

48

49 50 51

52

53 54 55

56

57 5958

60

61 62

63 64

65

66

67 68

69 70

71 72 73 74

75

76

77 78

GND 67H 67L 66H 66L 68H 68L 53H 53L 58H 58L 70H 70L 65H 65L 60H 60L

NC NC

78-Pin D-Sub Male Connector

enable the Bank 1 Analog Bus relays to close. The optional 34924T terminal blocks short these pins for you. This feature protects inadvertent routing of high voltages from the Analog Buses to the D-sub connector of the module.

Bank 2

Description Pin Description Pin Description Pin Description Pin Description Pin Description Pin

36H 3 43H 29 50H 57 57H 45 64H 55 COM2 H 9

36L 4 43L 30 50L 58 57L 46 64L 56 COM2 L 10

37H 7 44H 13 51H 21 58H 69 65H 73 Interlock 2 39

37L 8 44L 14 51L 22 58L 70 65L 74 Interlock 2 59

38H 11 45H 17 52H 25 59H 53 66H 63 GND 40

38L 12 45L 18 52L 26 59L 54 66L 64 GND 60

39H 15 46H 23 53H 67 60H 75 67H 61 No Connect 77

39L 16 46L 24 53L 68 60L 76 67L 62 No Connect 78

40H 19 47H 27 54H 33 61H 41 68H 65

40L 20 47L 28 54L 34 61L 42 68L 66

46 Keysight 34921A-34925A User’s Guide

Description Pin Description Pin Description Pin Description Pin Description Pin Description Pin

WARNING

NOTE

41H 1 48H 49 55H 37 62H 47 69H 31

41L 2 48L 50 55L 38 62L 48 69L 32

42H 5 49H 35 56H 43 63H 51 70H 71

42L 6 49L 36 56L 44 63L 52 70L 72

As a safety feature, interlock 2 pins (39 and 59) on Bank 2 must be shorted to enable the Bank 2 Analog Bus relays to close. The optional 34924T terminal blocks short these pins for you. This feature protects inadvertent routing of high voltages from the Analog Buses to the D-sub connector of the module.

34924T Terminal Blocks

Two terminal blocks are available to facilitate wiring connections to the 34924A module:

34924T-001 (Option 001) Terminal block with solder connectors

34924T-002 (Option 002) Terminal block with screw connectors

Keysight 34921A-34925A User’s Guide 47

All modules that connect to the internal DMM are interlock protected. This means that when an installed module is exposed (no terminal block or cable is connected), the Analog Bus relays are open and disconnected from the Analog Buses. See “Safety Interlock” on page 11 for further information.

34924T-001 Terminal Block

W

i

r

e

S

i

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e

:

2

A

W

G

T

y

p

i

c

a

l

2

0

A

W

G

M

a

x

This terminal block with solder-type connections is labeled with the model number and the abbreviated module name. In addition, space is available on the label for you to write the slot number.

48 Keysight 34921A-34925A User’s Guide

34924T-002 Terminal Block

B A N K

1

B

A

N

K

2

1

2

3 4 5 COM1

6

7

8 9 10 11

HLHLHLHLHLH

L

HLHLHLHL

HLHL

12

13

14 15 16

17

HLHLHLHL

HLHL

HLHLHLHLHLH

L

18

19

20 21 22 23

24

25

26 27 28

29

HLHLHLHL

HLHL

HLHLHLHLHLH

L

30

31

32 33 34 35

59

60

61 62 63 64

HLHLHLHLHLH

L

HLHLHLHL

HLHL

65

66

67 68 69

70

47

48

49 50 51 52

HLHLHLHLHLH

L

HLHLHLHL

HLHL

53

54

55 56 57

58

COM2

36

37 38 39

40

HLHLHLHL

HLHL

HLHLHLHLHLH

L

41

42

43 44 45 46

W

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:

2

0

A

W

G

T

y

p

i

c

a

l

1

8

A

W

G

M

a

x

This terminal block with screw-type connections is labeled with the model number and the abbreviated module name. In addition, space is available on the label for you to write the slot number.

Keysight 34921A-34925A User’s Guide 49

34925A 40/80-Channel Optically-Isolated FET Multiplexer

NOTE

The 34925A 40/80-Channel Optically-Isolated FET Multiplexer (40/80-Ch FET MUX) module is a high-speed and high-density FET MUX for high throughput production test. This module is divided into two equal banks of non-latching FET switches. This module also contains four armature Analog Bus relays. Through ABus1 and ABus2 you can connect any of the channels to the internal DMM for voltage or resistance measurements. When the power is off, all channel and Analog Bus relays open.

Using program commands or the mainframe front panel, you can control each of the FET channel switches individually, and configure this module for differential (2-wire or 4-wire) or single-ended (1-wire) mode. Refer to the simplified schematics on page 53 and page 58.

If you are using an Keysight 34925T-00x terminal block to connect your DUT to this module, be sure to use the terminal block that corresponds to your module configuration mode (Refer to the terminal block drawings on page 57 and

page 62):

34925T-001 (Option 001) Terminal block for differential (two- or four-wire) mode

34925T-002 (Option 002) Terminal block for single-ended (1-wire) mode

You can confirm the mode in which your module is configured by using the SYSTem:CTYPe? <slot number> program command. This command returns the identity of the plug-in module in the specified slot.

Whenever you change from 2- or 4-wire mode to 1-wire mode, or the reverse, you must cycle power on the 34980A for the configuration to take effect.

Two-Wire Mode

– two independent 20-channel 2-wire MUXes. This configuration requires

neither using external wiring nor connecting through the internal Analog Bus relays.

50 Keysight 34921A-34925A User’s Guide

– one 40-channel, 2-wire MUX. You must use external wiring or connect through

NOTE

the Analog Bus relays to for this configuration.

Four-Wire Mode

– You may configure the 34925A as a single 20-channel 4-wire MUX. This

configuration requires using neither external wiring nor connecting through the internal Analog Buses. For 4-wire resistance measurements, the instrument automatically pairs channel n on Bank 1 (source) with channel n+20 on Bank 2 (sense) to provide these connections. Four-wire controls occur only when doing 4-wire measurement operations through the internal DMM, such as MEASure:FRESistance? or scanning a channel previously configured as 4-wire.

One-Wire Mode

– two independent 40-channel 1-wire MUXes. This configuration requires

neither using external wiring nor connecting through the Analog Bus relays.

– one 80-channel 1-wire MUX. You must use external wiring or connect through

the Analog Bus relays for this configuration.

Because all bank relays supply only HI signals, you can apply a LOW signal through COM1 L or COM2 L when you are making 2-wire resistance measurements in 1-wire mode.

Interlock Protection

This module is interlock protected, which means whenever the D-sub connector end of the modules is exposed, the Analog Bus relays immediately open and disconnect from the Analog Buses. For more information, see “Safety Interlock” on page 11.

Keysight 34921A-34925A User’s Guide 51

Overvoltage Protection

This module also features high voltage detection (< 100 V) and current limiting circuitry to protect the FET relays. This circuitry senses current flows from input overvoltages. These overvoltages may come from either the MUX input or from the Analog Buses. In addition, each channel is also protected from input overvoltages with a resistor.

When overvoltage is detected, all relays (Analog Bus and FET) are opened. While in the overvoltage state, any attempts to close any Analog Bus or FET switch, results in an error status response from the module.

Once in the overvoltage state, you must restore normal module operation with one of these actions:

–using the SYSTem:CPON <slot> command. This affects only the module

specified.

–using the *RST command. This command resets the mainframe and all

installed modules to the Factory configuration. This affects all installed modules.

– cycling system power. This affects all installed modules.

If the overvoltage situation is not resolved, clearing the overvoltage will result in a new overvoltage event occurring immediately.

Further FET protection is assured only as one channel in each bank is closed at any time. Thus this module will operate as only a 1:N MUX module. For more information about FET channel closures, refer to page 13.

52 Keysight 34921A-34925A User’s Guide

34925A Simplified Schematic for Two- or Four-Wire Mode

Keysight 34921A-34925A User’s Guide 53

This drawing shows two independent 20-channel 2-wire MUXes. To change

026

027

028

029

030

031

032

033

034

035

036

037

038

039

040

021

022

023

024

025

001

002

003

004

005

006

007

008

009

010

011

012

013

014

015

016

017

018

019

020

H

L

H

L

H

L

H

L

ABus 2 DMM (SENS)

ABus 3

ABus 4

923

913 914

924922

912911

921

ABus 1 DMM (MEAS)

H

L

H

L

H

L

H

L

LH

LHLHLHLH

Bank 1

Bank 2

COM 1

COM 2

Analog Buses

Overvoltage Protection

(each channel)

100Ω

H

L

51.1Ω

11Ω 11Ω

100Ω

Current-Limiting Circuitry

100Ω

NOTE: The three-digit number assigned to each switch represents the channel number.

NOTE: Bank relays: FET non-latching Analog Bus relays: Armature non-latching

configuration modes, use the SYSTem:MODule:WIRE:MODE command.

54 Keysight 34921A-34925A User’s Guide

34925A D-Sub Connectors for Two- or Four-Wire Mode

Bank 1

For orientation, the D-sub connector end of the module is facing you.

Bank 1

Bank 2

17L

34

35

36 37

38

39 40

41

42

43 44 45

46

47 48 49

50

18

19 20

21 22

23

24

25 26

27 28

29 30 31 32

33

GND 6H 6L 16H 16L 12H 1 2L 8H 8L 18H 18L 10H 10L

NC NC NC NC

Reserved 11H 11L 7H 7L 17 H 13H 13L 9H 9L 19H 19L 15H 15L Int erlock 1

1 2 3 4 5 6 7 8 9 10111213 1415 1617

Interlock11H 1L 2H 2L 3H 3L

COM1HCOM

1L

4H 4L 14H 14L 5H 5L 20H 20L

50-Pin D-Sub Male Connector

WARNING

Description Pin Description Pin Description Pin Description Pin Description Pin

1H 1 6H 35 11H 19 16H 37 COM1 H 7

1L 2 6L 36 11L 20 16L 38 COM1 L 8

2H 3 7H 21 12H 39 17H 23 Interlock 1 17

2L 4 7L 22 12L 40 17L 24 Interlock 1 33

3H 5 8H 41 13H 25 18H 43 Reserved 18

3L 6 8L 42 13L 26 18L 44 GND 34

4H 9 9H 27 14H 11 19H 29 No Connect 47

4L 10 9L 28 14L 12 19L 30 No Connect 48

5H 13 10H 45 15H 31 20H 15 No Connect 49

5L 14 10L 46 15L 32 20L 16 No Connect 50

As a safety feature, interlock 1 pins (17 and 33) on Bank 1 must be shorted to enable the Bank 1 Analog Bus relays to close. The optional 34925T-001 (for 2-wire) terminal block shorts these pins for you. This feature protects inadvertent routing of high voltages from the Analog Bus to the D-sub connector of the module.

Keysight 34921A-34925A User’s Guide 55

Bank 2

34 35 36 37 38 39 40 41 42 43 44 45 46

47

48 49 50

GND 26H 26L 36H 36L 32H 32L 28H 28L 38H 38L 30H 30L

NC NC NC NC

37L

18 19

20

21

22

23 24 25 26 27 28 29 30 31 32 33

Reserved 31H 31L 27H 27L 37H 33H 33L 29H 29L 39H 39L 35H 35L Interlock 2

1234567891011121314151617

23L Interlock 221H 21L 22H 22L 23H

COM2HCOM

2L

24H 24L 34H 34L 25H 25L 40H 40L

50-Pin D-Sub Male Connector

WARNING

Description Pin Description Pin Description Pin Description Pin Description Pin

21H 1 26H 35 31H 19 36H 37 COM2 H 7

21L 2 26L 36 31L 20 36L 38 COM2 L 8

22H 3 27H 21 32H 39 37H 23 Interlock 2 17

22L 4 27L 22 32L 40 37L 24 Interlock 2 33

23H 5 28H 41 33H 25 38H 43 Reserved 18

23L 6 28L 42 33L 26 38L 44 GND 34

24H 9 29H 27 34H 11 39H 29 No Connect 47

24L 10 29L 28 34L 12 39L 30 No Connect 48

25H 13 30H 45 35H 31 40H 15 No Connect 49

25L 14 30L 46 35L 32 40L 16 No Connect 50

As a safety feature, interlock 2 pins (17 and 33) on Bank 2 must be shorted to enable the Bank 2 Analog Bus relays to close. The optional 34925T-001 (for 2-wire) terminal block shorts these pins for you. This feature protects inadvertent routing of high voltages from the Analog Buses to the D-sub connector of the module.

56 Keysight 34921A-34925A User’s Guide

34925T-001 Terminal Block for Two-Wire or Four-Wire Mode

NOTE

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2

0

A

W

G

T

y

p

i

c

a

l

1

8

A

W

G

M

a

x

This terminal block with screw-type connections is labeled with the model number and the abbreviated module name. In addition, space is available on the label for you to write the slot number.

All modules that connect to the internal DMM are interlock protected. This means that when an installed module is exposed (no terminal block or cable is connected), the Analog Bus relays are open and disconnected from the Analog Buses. See “Safety Interlock” on page 11 for further information.

If you are using an Keysight terminal block to connect your DUT to this module be sure to use the 34925T-001 terminal block that corresponds to the 2- or 4-wire configuration mode. An error will not be generated if you have installed a terminal block that doesn't match the present module configuration.

Keysight 34921A-34925A User’s Guide 57

34925A Simplified Schematic for One-Wire Mode

58 Keysight 34921A-34925A User’s Guide

HH

HHHH

ABus 2 DMM (SENS)

ABus 3

ABus 4

923

913

914

924922

912

911

921

ABus1 DMM (MEAS)

001

002

003

004

005

006

007

008

009

010

021

022

023

024

025

026

027

028

029

030

011

012

013

014

015

016

017

018

019

020

031

032

033

034

035

036

037

038

039

040

041

042

043

044

045

046

047

048

049

050

051

052

053

054

055

056

057

058

059

060

061

062

063

064

065

066

067

068

069

070

H

071

072

073

074

075

076

077

078

079

080

H

LHLH

LH

Bank 1

Bank 2

COM 2

COM 1

Analog Buses

Overvoltage Protection

(each channel)

100Ω

H

51.1Ω

11Ω 11Ω

100Ω

Current-Limiting Circuitry

NOTE: The three-digit number assigned to each switch represents the channel number.

NOTE: Bank relays: FET non-latching Analog Bus relays: Armature non-latching

This drawing shows two independent 40-channel, 1-wire MUXes. To change configuration modes, use the SYSTem:MODule:WIRE:MODE command.

Keysight 34921A-34925A User’s Guide 59

34925A D-Sub Connectors for One-Wired Mode

For orientation, the D-sub connector end of the module is facing you.

Bank 1

Bank 2

34

35

36 37

38

39 40

41

42

43 44 45

46

47 48 49

50

18

19 20

21 22

23

24

25 26

27 28

29 30 31 32

33

GND 11 1 2 31 32 23 24 15 16 35 36 19 20

NC NC NC NC

Reserved 21 22 13 14 33 25 26 17 18 37 38 29 30 Interlock 1

1 2 3 4 5 6 7 8 9 1011121314151617

Interlock1123456

COM1HCOM

1L

7 8 27 28 9 10 39 40

50-Pin D-Sub Male Connector

WARNING

Bank 1

Description Pin Description Pin Description Pin Description Pin Description Pin

1 1 11 35 21 19 31 37 COM1 H 7

2 2 12 36 22 20 32 38 COM1 L 8

3 3 13 21 23 39 33 23 Interlock 1 17

4 4 14 22 24 40 34 24 Interlock 1 33

5 5 15 41 25 25 35 43 Reserved 18

6 6 16 42 26 26 36 44 GND 34

7 9 17 27 27 11 37 29 No Connect 47

8 1018 2828 1238 30No Connect48

9 1319 4529 3139 15No Connect49

10 14 20 46 30 32 40 16 No Connect 50

As a safety feature, interlock 1 pins (17 and 33) on Bank 1 must be shorted to enable the Bank 1 Analog Bus relays to close. The optional 34925T-002 (for 1-wire) terminal block shorts these pins for you. This feature protects inadvertent routing of high voltages from the Analog Bus to the D-sub connector of the module.

60 Keysight 34921A-34925A User’s Guide

Bank 2

74

34

35

36 37

38

39 40

41

42

43 44 45

46

47 48 49

50

18

19 20

21 22

23

24

25 26

27 28

29 30 31 32

33

GND515271726364555675765960

NC NC NC NC

Reserved 61 62 53 54 73 65 66 57 58 77 78 69 70 I nterlock 2

1 2 3 4 5 6 7 8 9 1011121314151617

Interlock 241 42 43 44 45 46

COM2HCOM

2L

47 48 67 68 49 50 79 80

50-Pin D-Sub Male Connector

WARNING

Description Pin Description Pin Description Pin Description Pin Description Pin

411513561197137COM2 H 7

422523662207238COM2 L8

433532163397323Interlock 217

444542264407424Interlock 233

455554165257543Reserved 18

466564266267644GND34

479572767117729No Connect47

48 10 58 28 68 12 78 30 No Connect 48

49 13 59 45 69 31 79 15 No Connect 49

50 14 60 46 70 32 80 16 No Connect 50

As a safety feature, interlock 2 pins (17 and 33) on Bank 2 must be shorted to enable the Bank 2 Analog Bus relays to close. The optional 34925T-002 (for 1-wire) terminal block shorts these pins for you. This feature protects inadvertent routing of high voltages from the Analog Buses to the D-sub connector of the module.

Keysight 34921A-34925A User’s Guide 61

34925T-002 Terminal Block for One-Wire Mode

NOTE

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2

0

A

W

G

T

y

p

i

c

a

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1

8

A

W

G

M

a

x

This terminal block with screw-type connections is labeled with the model number and the abbreviated module name. In addition, space is available on the label for you to write the slot number.

All modules that connect to the internal DMM are interlock protected. This means that when an installed module is exposed (no terminal block or cable is connected), the Analog Bus relays are open and disconnected from the Analog Buses. See “Safety Interlock” on page 11 for further information.

If you are using an Keysight terminal block to connect your DUT to this module be sure to use the 34925T-002 terminal block that corresponds to the 1-wire configuration mode. An error will not be generated if you have installed a terminal block that doesn't match the present module configuration.

62 Keysight 34921A-34925A User’s Guide

Keysight 34921A-34925A User’s Guide 63

THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK.

64 Keysight 34921A-34925A User’s Guide

Index

Numerics

34921A

connector pinouts description external reference programming examples simplified schematic temperature sensor terminal block valid measurement functions, 10 wiring log

34922A

connector pinouts, 26 description programming examples simplified schematic terminal blocks valid measurement functions, 10 wiring log

34923A

connector pinouts, 35, 40 description programming examples simplified schematic terminal blocks valid measurement functions, 10 wiring log

34924A

connector pinouts, 46 description programming examples simplified schematic terminal blocks valid measurement functions, 10 wiring log

34925A

connector pinouts, 55, 60 description overload protection

,

, 37,

,

17

,

22

24

, 28,

28

31

, 37,

43

, 48,

48

51

,

22

42

20

22

,

22

,

30

,

, 34,

42

,

50

,

53

19

25

45

programming examples simplified schematic terminal blocks valid measurement functions, 10

13

wiring log

, 57,

C

connector pinouts

34921A 34922A 34923A 34924A 34925A

13

D

D-sub pinouts

34921A 34922A 34923A 34924A 34925A

E

13

39

external reference, 22

,

20

,

26

, 35, ,

46

, 55,

,

20

,

26

, 35, ,

46

, 55,

F

FET protection, 53

I

13

isothermal block, 22

O

operating considerations, 11 overload protection overvoltage protection

P

pinouts

, 57,

62

40

60

40

60

,

53

,

, 54,

62

53

13

59

34921A 34922A 34923A 34924A 34925A

S

safety notices, 4

T

temperature sensor, 22 terminal block

34921T, 23 34922T Option 001 34922T Option 002 34923T Option 001 34923T Option 002 34924T Option 001 34924T Option 002 34925T Option 001 34925T Option 002

,

20

,

26

, 35, ,

46

, 55,

40

60

,

29

,

30

,

37

,

42

,

49

,

50

,

57

,

62

Keysight 34921A-34925A User’s Guide 65

THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK.

66 Keysight 34921A-34925A User’s Guide

This information is subject to change without notice. Always refer to the Keysight website for the latest revision.

Printed in Malaysia

*34980-90021*

34980-90021

www.keysight.com

Keysight Technologies 34921A, 34922A, 34923A, 34924A, 34925A User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Safety Symbols

Additional Safety Notices

General

Before Applying Power

Ground the Instrument

Do Not Operate in an Explosive Atmosphere

Do Not Remove the Instrument Cover

Do Not Modify the Instrument

In Case of Damage

Waste Electrical and Electronic Equipment (WEEE) Directive 2002/ 96/EC

Product category:

Sales and Technical Support

Table of Contents

Low Frequency Multiplexer Modules

Multiplexer Module Capabilities

Measurement Functions for the Multiplexer Modules

Operating Considerations

SCPI Programming Examples for the Multiplexer Modules

34921A 40-Channel Armature Multiplexer with Low Thermal Offset

34921A Simplified Schematic

34921A D-Sub Connectors

34921T Terminal Block

34922A 70-Channel Armature Multiplexer

34922A Simplified Schematic

34922A D-Sub Connectors

34922T Terminal Blocks

34923A 40/80-Channel Reed Multiplexer

Two-Wire Mode

Four-Wire Mode

One-Wire Mode

34923A Simplified Schematic for Two- or Four-Wire Mode

34923A D-Sub Connectors for Two- or Four-Wire Mode

34923T-001 Terminal Block for Two-Wire or Four-Wire Mode

34923A Simplified Schematic for One-Wire Mode

34923A D-Sub Connectors for One-Wire Mode

34923T-002 Terminal Block for One-Wire Mode

34924A 70-Channel Reed Multiplexer

34924A Simplified Schematic

34924A D-Sub Connectors

34924T Terminal Blocks

34925A 40/80-Channel Optically-Isolated FET Multiplexer

Two-Wire Mode

Four-Wire Mode

One-Wire Mode

Interlock Protection

Overvoltage Protection

34925A Simplified Schematic for Two- or Four-Wire Mode

34925A D-Sub Connectors for Two- or Four-Wire Mode

34925T-001 Terminal Block for Two-Wire or Four-Wire Mode

34925A Simplified Schematic for One-Wire Mode

34925A D-Sub Connectors for One-Wired Mode

34925T-002 Terminal Block for One-Wire Mode

Index