Woodward HighPROtec MCDLV4, Manual, Page: 1093 / 1275

Supervision
Self Supervision
SSV
The protection devices are supervised by various check routines during normal operation and during the start-up
phase on faulty operation.
The protection devices are carrying out various self supervision tests.
Self Supervision within the devices
Supervision of... Supervised by... Action on detected issue...
Start phase The duration (permitted time) of the
boot phase is monitored. The device will be rebooted.
=> The device will be taken out of
service after three unsuccessful start
attempts.
Supervision of the duration of a
protection cycle (Software cycle) The maximum permitted time for a
protection cycle is monitored by a
timing analysis. The self-supervision contact will be
deenergized if the permitted time for
a protection cycle is exceeded (first
threshold).
The protection device will be
rebooted, if the protection cycle
exceeds the second threshold.
Monitoring of the communication
between Main and Digital Signal
Processor (DSP) The cyclic measured value
processing of the DSP is monitored
by the main processor. The device will be rebooted, if a
failure is detected.
The self-supervision contact will be
deenergized.
Analog-Digital-Converter The DSP does a plausibility check on
the digitalized data. Protection will be blocked, if a failure
is detected, in order to prevent faulty
tripping.
Supervision of data consistency after
an outage of the power supply.
(e.g. outage of the power supply
while changing the parameter
settings). An internal logic detects fragmentary
saved data after an outage of the
power supply. If the new data is incomplete or
corrupt, it will be deleted during the
reboot phase of the device. The
device will continue to work with the
last valid data set.
Data consistency in general Generation of check-sums. The device will be taken out of
service in case that inconsistent data
is detected that is not caused by an
outage of the power supply.
(fatal internal error).
1093 MCDLV4 DOK-HB-MCDLV4-2E