GBK60348: Issue 3 39
Fail-safe Operation 2.7.2.2
The fail-safe operation option provides additional protection against faults including
disconnected jack sockets (open circuit) and damaged switch circuit cables that
result in the UCI connections being either open circuit or short-circuit.
Failsafe UCI circuits are based on the following circuit. Note that either switch may be
omitted if not required.
When operating in fail-safe mode the UCI inputs detect the following resistance
bands.
Acceptable
Resistance Band (Ω)
Fault - Cable broken or plug disconnected