Figure 12: Power Supply Terminals
6.5.1 WATCHDOG
For space reasons, the Watchdog facility is also hosted on the power supply board. This checks the
operation of the IED's hardware and software when in service. The Watchdog facility provides two output
relay contacts, one normally open and one normally closed. These are used to indicate the health of the
unit's processor board and are driven by the main processor board.
Chapter 3 - Hardware Design MiCOM P747
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