Siemens Simatic 620 - Manual (Page 140)

Hardware Information
7-8
SIMATIC Box PC 620 Manual
A5E00131465-01
7.4.5 Fan Monitoring
Processor fan operation is monitored. If the fan should fail, the following reactions
are triggered:
Reaction Option
SOM application is displayed always
The temperature error remains stored until the cause of the fan failure has been
corrected in one of the following ways:
S Acknowledgement of the error message via the SOM program.
S Device restart.