Keysight Technologies 34921A - 34925 A 40;80-Channel FET Multiplexer; Module Description and Modes; Two-Wire and Four-Wire Modes

50 Keysight 34921A-34925A User’s Guide
34925A 40/80-Channel Optically-Isolated FET Multiplexer
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):
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.
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.
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
NOTE
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.