Siemens S7-300 Installation And Operating Manual page 101

Diagnostic message
Time monitoring activated
(watchdog)
EPROM error
RAM error
Processor failure
Internal error in read
circuit/test circuit
CRC signature error
Timeout of safety message
frame monitoring
Message frame error
Fail-safe signal modules
Installation and Operating Manual, 01/2010, A5E00085586-10
Possible causes of the problem
Overload due to diagnostics request
(SFCs)
Electromagnetic interference has
exceeded limits
Defective module
Electromagnetic interference has
exceeded limits
Defective module
Electromagnetic interference has
exceeded limits
Defective module
Switching rate exceeded
Defective module
CRC signature error during
communication between the CPU
and the module has occurred, for
example, due to electromagnetic
interference in excess, faults during
sign-of-life monitoring error or
standard program accesses F-SM.
Assigned monitoring time exceeded
Startup of the fail-safe signal module
Sign-of-life and/or CRC signature
entered in the data message frame
Digital modules
8.3 SM 326; DI 24 x DC 24V
Corrective measures
Reduce the number of
diagnostics requests
Eliminate the interference
Replace the module
Eliminate the interference and
cycle the power supply OFF/ON
Replace the module
Eliminate the interference
Replace the module
Reduce switching rate
Replace the module
Eliminate the interference
Check the monitoring time
parameters
—
Check the sign-of-life and CRC
signature entries in the data
message frame for "0" value
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