Keysight 34951A User manual

Keysight 34951A 4-Channel
Isolated D/A Converter with
Waveform Memory Module
User’s Guide

2 Keysight 34951A User’s Guide
Notices
Copyright Notice
© Keysight Technologies 2008-2019
No part of this manual may be
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
34980-90051
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 hardware 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
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perform, display, or disclose
commercial computer software or
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documentation. No additional
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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,
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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
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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
CAUTION
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.
WARNING
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.

Keysight 34951A User’s Guide 3
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) Frame or chassis (ground) terminal
Standby supply. Unit is not completely
disconnected from ac mains when
switch is off
Caution, risk of electric shock
Caution, risk of danger (refer to this
manual for specific Warning or Caution
information)

4 Keysight 34951A User’s Guide
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.

Keysight 34951A User’s Guide 5
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.

6 Keysight 34951A User’s Guide
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)

Keysight 34951A User’s Guide 7
Table of Contents
Safety Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Additional Safety Notices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Before Applying Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Ground the Instrument . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Do Not Operate in an Explosive Atmosphere . . . . . . . . . . . . . . . . . . .4
Do Not Remove the Instrument Cover . . . . . . . . . . . . . . . . . . . . . . . .5
Do Not Modify the Instrument . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
In Case of Damage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Waste Electrical and Electronic Equipment (WEEE) Directive
2002/96/EC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Product category: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Sales and Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
34951A 4-Channel Isolated D/A Converter with Waveform Memory
Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Operating Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Level Output Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Waveform (Trace) Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Clock In . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Clock Out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Trigger In . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Trigger Out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Auto-Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
34951A SCPI Programming Examples . . . . . . . . . . . . . . . . . . . . . . . . . .13
Level Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Waveform Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
External Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
External Trigger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Auto Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Configuring a DAC Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
34951A Simplified Block Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

8 Keysight 34951A User’s Guide
34951A D-Sub Connector Pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
34951T Terminal Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Keysight 34951A User’s Guide 9
34951A 4-Channel Isolated D/A Converter with Waveform Memory
Module
The 34951A 4-Ch Isolated D/A module (DAC module) has four independent,
isolated DAC channels that output DC voltage up to ±16V or DC current up to
±20 mA (Level Output Mode). Since the DACs are electrically isolated, you can
stack or combine multiple DACs to have up to ±64 V on a module. It also features
a capability to specify and store waveform points (Waveform Trace Mode).
You can control each channel manually, or use the onboard memory to store
multiple sequenced points.
Operating Considerations
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 the DAC module.
Level Output Mode
The module can generate voltages between -16 V DC and +16 V DC at 500 μV
resolution on any or all four channels. Each channel configured for voltage output
has hardware remote-sensing capability to ensure that an accurate voltage is
present at the load. With the remote sensing feature, the DAC channel outputs an
additional voltage to compensate for the voltage drop in the test leads. Thus,
using the sense connections, the load voltage equals the programmed voltage as
long as the resistance in each sense lead is less than 2.5Ωand the maximum
voltage drop in the output leads is 0.5 volts.
When using the remote-sensing feature, connect sense wires from the load to the
High Sense and Low Sense terminals for the desired channels.
NOTE
To ensure that an accurate voltage is present at the loads, it is recommended
that you use remote-sensing. However, if remote-sensing is not used, do not
connect loads or cables to the remote-sensing terminals (H Sense and L Sense).

10 Keysight 34951A User’s Guide
Each channel can also generate current between -20 mA and +20 mA at
630 nA resolution. When outputting current the High Sense and Low Sense
terminals are not used and are opened. For protection, each channel incorporates
a fuse that will open at greater than 20 mA. If an overload condition exists, the
fuse will open, but no error or SRQ will be generated. To reset the fuse, remove
the overload and wait a few minutes for the fuse to cool.
Waveform (Trace) Mode
Using the internal waveform point storage, you can output provided sine, square,
or ramp and triangle wave shapes, or define your own wave shape with up to
512,000 points. The module can output points with a settling time of 40 μs and a
200 kHz point-to-point update rate.
The on-board memory provides storage for you to create up to 32 voltage or
current waveforms. You can apply a different waveform to each channel to output.
Or you can apply the same waveform to more than one channel. For each channel
you can designate the gain, frequency, and/or offset for its output.
The waveforms are stored in volatile memory. Therefore, whenever power to the
34980A is cycled, the volatile memory empties of data it has contained.
The waveform feature of the 34951A is not intended as a full-featured substitute
for a function generator, but as a means of storing point-to-point updates.
Clock In
You can configure each DAC channel on the module to synchronize off either an
internally-generated 20 MHz clock or the positive edge of an external
user-supplied clock.
An external clock must be less than 10 MHz or indeterminate behavior will result.
Additionally, as the maximum point-to-point update rate of the DACs is 200 kHz,
if you configure a DAC to run off an external clock, you will need to ensure that the
correct clock divisor is also configured for that DAC. For example, if you supply a
10 MHz external clock, the minimum clock divisor is 50 because the maximum
update rate is 200 kHz. If a clock divisor less than the minimum is configured,
indeterminate behavior will results. Thresholds for the Clock In are 5 V TTL
tolerant.

Keysight 34951A User’s Guide 11
Clock Out
There is one clock output on the DAC module, which you can configure to output
at frequencies up to 10 MHz. Since it uses a 16-bit clock divisor, the available
output frequencies range in steps of 20 MHz/216 with a minimum output
frequency of 305 Hz. The output impedance of the Clock Out is 50 Ω.
Trigger In
You can configure each DAC on the module to trigger off an externally provide
Trigger In that has a pulse width greater than 100 ns. The Trigger In line is 5V TTL
tolerant.
Trigger Out
The DAC module can source a TTL level Trigger Out. Trigger Out has a pulse width
between 5 and 10 μs.
Auto-Calibration
The 34951A features auto-calibration (auto-cal). Upon receipt of the
CALibration:MODule? command, you can adjust all four channels of the DAC
module. The adjustments, performed under complete control of the 34980A,
require approximately one minute per module.
NOTE
The line between external Clock Out and external Clock In is shared. You can use
the external Clock Out to provide the external Clock In signal. However, both a
user-supplied external clock and the module’s Clock Out cannot drive the line at
the same time.
NOTE
The line between external Trigger Out and external Trigger In is shared. You can
use the external Trigger Out to provide the external Trigger In signal. However,
both a user-supplied external trigger and the 34951A Trigger Out cannot drive
the line at the same time.

12 Keysight 34951A User’s Guide
Before performing an auto calibration, be sure to allow a one-hour warm-up of
the DMM and 34951A module. The adjustment is valid for 90 days for
temperatures within 5 oC of the auto-cal temperature. For the calibration
constants to be saved, calibration security must be off. Otherwise, the new
calibration constants can be used while power is on. But when power is lost, the
DAC module will revert to using the previously stored calibration constants. For
SCPI programming examples for the auto-cal, refer to page 15.
WARNING
Because the auto-cal uses the internal DMM, do not route signals on ABus1
when performing an auto-cal of a DAC module. Do not apply a signal to
ABus1 via the Analog Bus connector on the rear of the mainframe (pins 4, 5,
and 9). The auto-cal will abort if a signal is detected on ABus1.

Keysight 34951A User’s Guide 13
34951A SCPI Programming Examples
The programming examples below provide you with SCPI command examples to
use for actions specific to the DAC module.
The slot and channel addressing scheme used in these examples follow the form
sccc where sis the mainframe slot number (1 through 8) and ccc is the three-digit
channel number. Valid channels for this module are 1-4. For information on
specific configurations, refer to the simplified schematic on page 17.
For complete information on the SCPI commands used to program the 34980A,
refer to the Keysight 34980A Programmer’s Reference which can be downloaded
from www.keysight.com/find/34980A.
Level Mode
Example: Outputting a DC voltage level This command sets the output
voltage level for the specified DAC channels. After setting the desired level, send
the OUTPut:STATe command to close the corresponding output relay and enable
outputs from the specified channels. The following command outputs +2.5 V DC
on DAC channels 1 and 2 for a module in slot 4.
SOURce:VOLTage 2.5,(@4001,4002)
OUTPut:STATe ON,(@4001,4002)
Example: Outputting a current level This command sets the output current
level on the specified channels on the DAC module. After setting the desired level,
send the OUTPut:STATe command to close the corresponding output relay and
enable outputs from the specified channels. The following command outputs
+5 mA on DAC channels 1 and 2 for a module in slot 4 and closes the output relay.
SOURce:CURRent 5E-3,(@4001,4002)
OUTPut:STATe ON,(@4001,4002)
Waveform Mode
Example: Downloading a waveform to memory and outputting waveform
from DACs
The following command segment downloads a 1000-point sine
waveform to memory on the module in slot 4 and outputs the waveform from DAC
channels 1 and 2. The trace name is "TEST_SINE".

14 Keysight 34951A User’s Guide
TRACe:FUNCtion 4,SINusoid, TEST_SINE, 1000
SOURce:FUNCtion:TRACe TEST_SINE,(@4001,4002)
OUTPut:STATe ON,(@4001,4002)
SOURe:FUNCtion:ENABle ON,(@4001,4002)
Example: Downloading trace points to memory and outputting waveform
from DACs
The following command segment downloads seven trace points to memory on the
module in slot 4 and output the waveform from DAC channels 1 and 2. The trace
name is "NEG_RAMP".
TRACe:DATA 4,NEG_RAMP, 1, .67, .33, 0, -.33, -.67, -1
SOURce:FUNCtion:TRACe NEG_RAMP,(@4001,4002)
OUTPut:STATe ON,(@4001,4002)
SOURe:FUNCtion:ENABle ON,(@4001,4002)
Example: Setting the amplitude of a waveform for offset and gain
The following commands set the offset to 5.25 and the gain to 1.5 on DAC
channels 1 and 2 of a module in slot 4.
SOURce:MODE VOLTage,(@4001,4002)
SOURce:FUNCtion:VOLTage:OFFSet 5.25,(@4001,4002)
SOURce:FUNCtion:VOLTage:GAIN 1.5,(@4001,4002)
Example: Setting cycle count for a waveform The following command
segments turn off the trace output mode on DAC channels 1 and 2 in slot 4, set
the cycle count to 100, then turn the trace output mode back on.
SOURce:FUNCtion:ENABle OFF,(@4001,4002)
SOURce:FUNCtion:TRACe:NCYCles 100,(@4001,4002)
SOURce:FUNCtion:ENABle ON,(@4001,4002)
Example: Deleting a waveform The following command deletes the trace
named "TEST_WFORM" from the module in slot 4.
TRACe:DELete 4,TEST_WFORM

Keysight 34951A User’s Guide 15
External Clock
Example: Selecting an external clock source and setting a clock divisor
The first command selects the external clock source on DAC channels 1 and 2 in
slot 4. The external clock input is shared between these two channels. The second
command sets the clock divisor to 100 on the same DAC channels (the external
clock input signal is divided by 100).
SOURce:FUNCtion:CLOCk:SOURce EXTernal,(@4001,4002)
SOURce:FUNCtion:CLOCk:EXTernal:DIVisor 100,(@4001,4002)
Example: Outputting a clock The following commands set the clock output
frequency for slot 4 to 5 kHz and enable the output.
SOURce:MODule:CLOCK:FREQuency 5E+3,4
SOURce:MODule:CLOCK:STATE ON,4
External Trigger
Example: Selecting the external trigger source and issuing trigger source
The following command segment enables the trigger output mode on a DAC
module installed in slot 4, then enables the external trigger source on DAC
channels 1 and 2. The last command issues an external trigger pulse from the
module.
SOURce:MODule:TRIGger:OUTPut ON,4
SOURce:FUNCtion:TRIGger:SOURce EXTernal,(@4001,4002)
SOURce:MODule:TRIGger:EXTernal:IMMediate 4
Auto Calibration
Example: Performing an auto calibration on all DAC channels This
command performs an auto-cal of all four channels on a DAC module. Because
the auto-cal takes can take up to one minute per DAC channel, you may want to
increase the time-out value of your programming application prior to sending this
command.
The following command performs an auto-cal of a DAC module in slot 5 and
returns a pass/fail indication.
CALibration:MODule? 5

16 Keysight 34951A User’s Guide
The following command performs an auto-cal of all 34951A DAC modules in a
mainframe.
CALibration:MODule? ALL
Example: Effects of using the secure state command on storing calibration
constants
The following command removes instrument security, and the
calibration constants are stored in non-volatile memory if sent before the
CALibration:MODule? command.
CALibration:SECure:STATe OFF <security code>
If the instrument is secured at the time of auto-cal, the calibration constants are
stored in volatile memory and are lost when power is turned off. The *RST
command will not discard the calibration constants. The command to secure the
instrument is:
CALibration:SECure:STATe ON <security code>
Configuring a DAC Module
Example: Querying the system for module identify (all modules) The
following command returns the identify of the module installed in slot 7.
SYSTem:CTYPe? 7
Example: Resetting the module(s) to power-on state The following
command resets a module in slot 4 to its power-on state.
SYST:CPON 4
NOTE
The default security code is AT34980.
NOTE
Using this command will erase any downloaded waveforms.

Keysight 34951A User’s Guide 17
34951A Simplified Block Diagrams
The following diagram shows how the module is generally configured.
For more detail on the internal configuration of each DAC channel, see the next
page.
16 Bits
DAC
1
16 Bits
DAC
2
16 Bits
DAC
3
16 Bits
DAC
4
34951A Module User-Supplied Connections
Channel 001
Channel 002
Channel 003
Channel 004
Ext Clock In/Out
Ext Trig In/Out
Ext Clock Out
Enable
Ext Trig Out
Enable
Int Clock Int Trig

18 Keysight 34951A User’s Guide
The following diagram shows individual DAC channel configuration. All channels
are configured the same.
16 Bits
Waveform
Memory
<ch#> H Sense (voltage)
<ch#> L Sense (voltage)
<ch#> H (voltage, + current)
<ch#> L (voltage, - current)
Calibration Constant
(non-volatile memory)
Immediate
Data
25 mA Thermal Fuse
(resettable)
34951A Module User-Supplied Connections
(1 of 4 Channels)
DAC x
Control Logic
Internal
Clock
Internal
Trigger
Ext Clock In/Out
Ext Trig In/Out
Sense relays are not closed in current output mode

Keysight 34951A User’s Guide 19
34951A D-Sub Connector Pinout
50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34
GND GND GND GND GND GND GND GND GND GND GND GND GND GND GND GND GND
33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18
17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
GNDGND NC 4 L4H3L3H
GNDGND
NC2L2HGND NC1L1H GND
EXT
CLKGND
4L
Sense
4H
Sense GNDTRIGGND
2L
Sense
2H
Sense
1L
Sense
1H
Sense GND
3L
Sense
3H
Sense GNDGND
50-Pin D-Sub
Female Connector
Description Socket Description Socket Description Socket Description Socket Description Socket
1L 15 3L Sense 21 GND 8 GND 34 GND 44
1H 16 3H Sense 22 GND 9 GND 35 GND 45
1L Sense 31 4L 3 GND 13 GND 36 GND 46
1H Sense 32 4H 4 GND 17 GND 37 GND 47
2L 11 4L Sense 19 GND 18 GND 38 GND 48
2H 12 4H Sense 20 GND 23 GND 39 GND 49
2L Sense 27 External Clock 24 GND 26 GND 40 GND 50
2H Sense 28 Trigger 25 GND 29 GND 41 No Connect 2
3L 5 GND 1 GND 30 GND 42 No Connect 10
3H 6 GND 7 GND 33 GND 43 No Connect 14

20 Keysight 34951A User’s Guide
34951T Terminal Block
Each terminal block 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.
WireSize:
20AWGTypical
18AWGMax