Watchdog Protections - Siemens SINAMICS PERFECT HARMONY GH180 Function Manual

NXGPro+ Control Description

4.9 Watchdog Protections

4.9 Watchdog Protections
The following internal watchdog protections function across all control modes. The purpose of
watchdog protection is to shut down the drive if an internal error were to occur during operation.
The watchdog protections are:
• Hardware watchdog - This watchdog monitors the functionality of the modulator. In case of
a trip, it disables all fiber optic transmission channels.
• I/O watchdog - This watchdog is built into the system firmware as part of the hardware. On
an I/O watchdog trip, the digital outputs will open or close based on the parameter settings
for each module. The default is to open.
For analog outputs, the following responses are possible based on system parameter
settings:
– Default setting: the analog outputs are all set to zero.
– The analog outputs will use the default values set in the parameters.
– The analog outputs will retain the last values set in the parameters.
Any circuitry connected to these circuits will be affected with one of these responses.
• CPU watchdog - This watchdog triggers if any processes of the drive's operating system stop
functioning. The watchdog is held off for 180 seconds at boot up. This feature, which is
enabled by the Enable Watchdog parameter (2971) monitors the state of all processes, and
trips the drive up to 60 seconds before any processes are non-functioning. Enable Watchdog
parameter (2971) is located in the Watchdog Menu (2970). For details, refer to
Section Options for Drive Menu (2) of Chapter Parameter Assignment/Addressing.
• Input breaker (M1 Permit) watchdog - This watchdog is built into the system firmware as part
of the hardware. It causes the input breaker close permissive relay (M1) to open on a
watchdog trip.
• Modulator watchdog - This watchdog disables all cell outputs if the CPU stops
communicating with the modulator. Since the CPU has stopped functioning properly, no
fault condition can display but the power electronics will shut down via the modulator
watchdog.
If the external Wago I/O system is used, the Wago watchdog must be enabled. Refer to "Wago
timeout" parameter (2850) for additional information.
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NXGPro+ Control Manual
Operating Manual, A5E50491925A