DESCRIPTION AND OPERATION
BUS FAULT TIMER
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I-E96-310B
®
BUS FAULT TIMER
The bus fault timer is a one-shot timer that is reset by the I/O
expander bus clock. The control module generates the bus
clock. If the clock stops (indicating a control module error or
failure), the bus fault timer times out in ten milliseconds. This
causes the digital outputs to change to their default values. A
red front panel status LED indicates a bus fault (time-out con-
dition).
STATUS LED INDICATOR
A faceplate module status LED indicator shows the operating
state of the DSO module. Circuits on the DSO module deter-
mine the module status and light the LED accordingly. The
operating procedures section explains the indications, and the
troubleshooting section explains corrective actions to take.
