Agilent Technologies Switch/Measure manual 34980A User’s Guide 103

Low Frequency Multiplexer Switch Modules 4

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, refer to page 96 and page 105.

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

34980A User’s Guide 103