Fault/Inhibit System Protection - Keysight Technologies BT2152A Operating And Service Manual

OUTP:INH:MODE LATC
OUTP:INH:MODE OFF

Fault/Inhibit System Protection

As shown in the following figure, when the Fault outputs and Inhibit inputs of several instruments are
daisy-chained, an internal fault condition in one of the units will disconnect all channels without
intervention by either the controller or external circuitry. Note that when using the Fault/Inhibit signals
in this manner, both signals must be set to the same polarity.
Also, as shown in the figure, you can also connect the Inhibit input to a manual switch or external
control signal that will short the Inhibit pin to common whenever it is necessary to disconnect all
channels. Negative polarity must be programmed for all pins in this case. You can also use the Fault
output to drive an external relay circuit or signal other devices whenever a protection fault occurs.
Clearing a System Protection Fault
To restore all instruments to a normal operating condition when a fault condition occurs in a daisy-
chained system protection configuration, two fault conditions must be removed:
1. The initial protection fault or external Inhibit signal.
2. The subsequent daisy-chained fault signal (which is sourced by the Inhibit signal).
Even when the initial fault condition or external signal is removed, the fault signal is still
active and will continue to disconnect the channels of all the units.
To clear the daisy-chained fault signal if the operating mode of the Inhibit input is Live, simply clear the
output protection on any ONE unit as explained under Clearing Protection Functions. If the operating
mode of the Inhibit input is Latched, turn off the Inhibit input on ALL units individually. To re-enable the
chain, re-program the Inhibit input on each unit to Latched mode.
Keysight BT2152A Operating and Service Guide
\\ sets the inhibit mode to Latched
\\ sets the inhibit mode to Off
3 Operating the Analyzer
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