Keysight 34921A-34925A User’s Guide 9Low Frequency Multiplexer ModulesThis User’s Guide covers the following five plug-in modules for the Keysight34980A Multifunction Switch/Measure Unit:Multiplexer Module CapabilitiesEach multiplexer (MUX) module features two banks of channels, providing broadmultiplexing and measurement capabilities. Briefly:– You can connect a MUX to an external instrument, and/or switch multipleanalog signals to the internal DMM.– With the 34921A, 34922A, 34923A, and the 34924A modules, you can closemore than one channel in each bank simultaneously (N:1 configuration).– Since the 34925A module is protected with overvoltage circuitry, you can closeonly one channel in each bank at one time (1:N configuration).– You can connect multiple MUXes to the built-in Analog Buses, which allow youto scan as many as 560 2-wire (differential) channels or 640 1-wire(single-ended) channels in one 34980A mainframe.34921A 40-channel armature multiplexer w/low thermal offset34922A 70-channel armature multiplexer34923A 40/80-channel reed multiplexer34924A 70-channel reed multiplexer34925A 40-channel optically isolated FET multiplexer