Siemens S7-300 Installation And Operating Manual page 123

Diagnostic message
Internal supply voltage of
the module failed
Time monitoring activated
(watchdog)
EPROM error
RAM error
Internal error in read
circuit/test circuit or
defective sensor supply
Processor failure
Parameter assignment
error (with specification of
a consecutive number)
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
Internal fault at the L+ supply voltage Replace the module
Overload due to diagnostics request
(SFCs)
Electromagnetic interference has
exceeded limits
Defective module
Electromagnetic interference has
exceeded limits
Defective module
Defective module
Electromagnetic interference has
exceeded limits
Defective module
Switching rate exceeded
Error in dynamic parameter
reassignment
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
8.4 SM 326; DI 8 x NAMUR
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
Replace the module
Eliminate the interference
Replace the module
Reduce switching rate
Check the parameter
assignment in the user program
Contact SIMATIC Customer
Support if necessary
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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