Keysight 34922A - One-Wire Mode and Signal Notes

Keysight 34921A-34925A User’s Guide 71
– one 40-channel, 2-wire MUX. You must use external wiring or connect through
the Analog Bus relays to for this configuration.
Four-Wire Mode
– You may configure the 34925A as a single 20-channel 4-wire MUX. This
configuration requires using neither external wiring nor connecting through the
internal Analog Buses. For 4-wire resistance measurements, the instrument
automatically pairs channel n on Bank 1 (source) with channel n+20 on Bank 2
(sense) to provide these connections. Four-wire controls occur only when
doing 4-wire measurement operations through the internal DMM, such as
MEASure:FRESistance? or scanning a channel previously configured as
4-wire.
One-Wire Mode
– two independent 40-channel 1-wire MUXes. This configuration requires
neither using external wiring nor connecting through the Analog Bus relays.
– one 80-channel 1-wire MUX. You must use external wiring or connect through
the Analog Bus relays for this configuration.
Interlock Protection
This module is interlock protected, which means whenever the D-sub connector
end of the modules is exposed, the Analog Bus relays immediately open and
disconnect from the Analog Buses. For more information, see “Safety Interlock” on
page 19.
NOTE
Because all bank relays supply only HI signals, you can apply a LOW signal
through COM1 L or COM2 L when you are making 2-wire resistance
measurements in 1-wire mode.