Error Handling For The S7-200 Cpu - Siemens Simatic S7-200 System Manual

6.9

Error Handling for the S7-200 CPU

The S7-200 CPU classifies errors as either fatal errors or non-fatal errors. You can use
STEP 7-Micro/WIN to view the error codes that were generated by the error. Figure 6-16
shows the dialog box that displays the error code and the description of the error. Refer to
Appendix C for a complete listing of the error codes.
CPU Information
General Information
Module Errors
Module 0:
Module 1:
Module 2:
Module 3:
CPU Errors
Fatal:
NON-Fatal:
Figure 6-16
Responding to Fatal Errors
Fatal errors cause the CPU to stop the execution of your program. Depending upon the
severity of the fatal error, it can render the CPU incapable of performing any or all functions.
The objective for handling fatal errors is to bring the CPU to a safe state from which the CPU
can respond to interrogations about the existing error conditions. When a fatal error is
detected by the CPU, the CPU changes to the STOP mode, turns on the System Fault LED
and the STOP LED, and turns off the outputs. The CPU remains in this condition until the
fatal error condition is corrected.
Once you have made the changes to correct the fatal error condition, you must restart the
CPU. You can restart the CPU either by turning the power off and then on, or by changing
the mode switch from RUN or TERM to STOP. Restarting the CPU clears the fatal error
condition and performs power-up diagnostic testing to verify that the fatal error has been
corrected. If another fatal error condition is found, the CPU again sets the fault LED
indicating that an error still exists. Otherwise, the CPU begins normal operation.
There are several possible error conditions that can render the CPU incapable of
communication. In these cases, you cannot view the error code from the CPU. These types
of errors indicate hardware failures that require the CPU module to be repaired; these
conditions cannot be fixed by changes to the program or clearing the CPU memory.
S7-200 Programmable Controller System Manual
C79000-G7076-C230-02
Basic Concepts for Programming an S7-200 CPU
Error Status Module Configuration
Not present
Not present
Not present
Not present
0 No fatal errors present.
0 No non-fatal errors present.
CPU Information Dialog: Error Status Tab
DP Status
Module 4: Not present
Module 5: Not present
Use the description and the code
Module 6: Not present
for troubleshooting the possible
cause of the error.
Close
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