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July 2025
34921A
Keysight/Agilent 34921A, 40 Two-Wire Channels, 300 Volt, Armature Multiplexer for 34980A
Actual item may vary if no part number is provided on quote request.
✔ 2 Year Warranty Included
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Andrew Gar**** Verified Buyer
" Amazing to work with and had my order within 1 week after purchasing with all NI certs and data that were needed. "
March 2025
Said Sai**** Verified Buyer
" Competent contact for highly specialized components. The support team is very knowledgeable. Many thanks for the help and the fast shipping! "
January 2025
Bob C**** Verified Buyer
" Jason was able to get our emergency situation taken care of quickly and professionally. "
May 2025
Gregg Flecki**** Verified Buyer
" Great service and great products. This is my 2nd time using Apex Waves, truly impressed. "
January 2025
Carol Zimme**** Verified Buyer
" Very responsive and helpful, competitive pricing. Good source! "
July 2025
Andrew Gar**** Verified Buyer
" Amazing to work with and had my order within 1 week after purchasing with all NI certs and data that were needed. "
March 2025
Said Sai**** Verified Buyer
" Competent contact for highly specialized components. The support team is very knowledgeable. Many thanks for the help and the fast shipping! "
January 2025
Bob C**** Verified Buyer
" Jason was able to get our emergency situation taken care of quickly and professionally. "
May 2025
Gregg Flecki**** Verified Buyer
" Great service and great products. This is my 2nd time using Apex Waves, truly impressed. "
January 2025
Keysight/Agilent 34921A Armature Multiplexer for 34980A
The Keysight 34921A 40-Channel Armature Multiplexer is a multi-purpose switch module created specifically to support the Keysight 34980A Multifunction Switch/Measure Unit. The Keysight 34921A has forty (40) armature relay channels, along with four additional fused inputs that provide a total of 44 channels to be used to acquire data and route signals. The Keysight 34921A can operate at voltages up to 300 Vdc/Vrms and currents up to 2 amperes. With an internal digital multimeter, the Keysight 34921A can scan at speeds of up to 100 channels per second.
Designed to support low-level signal switching, the Keysight 34921A will exhibit minimal thermal offset voltage. Additionally, there is a built-in thermocouple reference junction available on the optional 34921T terminal block, allowing users to accurately measure temperatures. Two banks of twenty (20) latching armature switches are provided in the Keysight 34921A. Users have flexibility to configure the module as either two separate twenty (20)-channel two-wire multiplexers; one twenty (20)-channel four-wire multiplexer to be used for resistance measurements utilizing automatic channel pairing; or a single fifty (50)-channel two-wire multiplexer by connecting external wires or internal analog bus relays. In addition to the twenty (20) two-wire relay channels, there are also four (4) dedicated fused current channels that permit measurement of AC and DC currents without using external shunt resistors. The fused current channels utilize make-before-break switching methods to maintain continuous current flow during channel changes.
There are nine (9) analog bus relays that connect any channel to the system's analog buses or to the DMM current input. The analog bus relays do not short circuit the signals being measured during the scanning process due to the use of break-before-make relay sequences. Multiple channels may be closed simultaneously in non-scanning modes.
There is a safety interlock present in the Keysight 34921A, which automatically opens all analog bus relays when the D-sub connector is exposed. When powered off, each of the channel relays retains its previous state. All analog bus relays remain open. The Keysight 34921A is necessary for high-density automated test systems requiring flexible and dense switching capabilities for measuring sensors, thermocouples, and combinations of both voltage and current in a variety of industrial automation, research and development, and manufacturing applications.
| Model Name | Keysight/Agilent 34921A |
|---|---|
| Part Type | 40-Channel Armature Multiplexer |
| Host Compatibility | Keysight 34980A |
| Total Channels | 44 total |
| Max Voltage / Current | 300 V / 2 A |
| Scan Speed | 100 ch/s |
| Relay Type | Latching, break-before-make |
| Operating Modes | Dual 20x1, 20x1 4-wire, 40x1 |
| Current Measurement | 4 fused, make-before-break |
| Analog Bus Relays | 9, for internal DMM |
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