GE MiCOM P40 Technical Manual page 95

P446SV Chapter 4 - Software Design
If the problem is with the battery status or the IRIG-B board, the device continues in operation. For problems
detected in any other area, the device initiates a shutdown and re-boot, resulting in a period of up to 10 seconds
when the functionality is unavailable.
A restart should clear most problems that may occur. If, however, the diagnostic self-check detects the same
problem that caused the IED to restart, it is clear that the restart has not cleared the problem, and the device takes
itself permanently out of service. This is indicated by the ''health-state' LED on the front of the device, which
switches OFF, and the watchdog contact which switches ON.
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