Keysight DAQ970A Guia Del Usuario página 208

3 Features and Functions
DAQM908A 40-channel Single-ended Multiplexer
The module is divided into two banks of 20 channels each. All of the 40 channels switch HI only, with a common LO
for the module. Use this module for high-density switching applications which require single-wire inputs with a
common LO.
Only one channel can be closed at a time, closing one channel will open the previously closed channel.
This module cannot be used to directly measure current or any 4-wire measurements.
TO PREVENT ELECTRICAL SHOCK
To prevent electrical shock, use only wire that is rated for the highest voltage to any channel. Before removing
a module cover, turn off all power to external devices connected to the module.
CAUTION WITH MULTIPLE SIGNALS
To avoid the possibility of multiple signal sources becoming connected together, we recommend when
multiplexing two or more sources they should be connected on separate modules or on separate banks of the
same module.
CAUTION WITH HAZARDOUS VOLTAGES
When any channel is connected to a hazardous voltage source, all channels in the module should be treated as
hazardous and all channel wiring in the module should be rated for the maximum voltage applied. Ther-
mocouples attached to any other channel on the module should have insulation rated for the maximum
voltage, or have additional insulation added rated for the maximum voltage and should be isolated from
conductive parts using a thermal compound or tape rated for the maximum voltage applied. Do not mount,
move, or remove any thermocouples when the device under test is connected to a supply source.
ENVIRONMENTAL HEALTH AND SAFETY
When any channel is connected to a hazardous voltage source, the instrument and the device under test
should be supervised, following local EHS practices to restrict access.
208 Keysight DAQ970A/DAQ973A User's Guide