Error codes
C.4 PLC fatal error codes
S7-200 SMART
796
System Manual, V2.3, 07/2017, A5E03822230-AF
C.4
PLC fatal error codes
Overview
Fatal errors cause the PLC to stop the execution of your program. Depending on the severity
of the error, a fatal error can render the PLC incapable of performing any or all functions.
The objective for handling fatal errors is to bring the PLC to a safe state from which the PLC
can respond to interrogations about the existing error conditions.
The PLC performs the following tasks when a fatal error is detected.
●
Changes to STOP mode
●
Turns on both the System Fault LED and the STOP LED
●
Turns off the outputs
The PLC remains in this condition until the fatal error is corrected. The table shown below
provides a list with descriptions for the fatal error codes that can be read from the PLC.
STEP 7-Micro/WIN SMART displays the error codes generated by the PLC, along with a
brief description, in the PLC Information dialog. To access PLC information, click the PLC
button
from the Information area of the PLC menu ribbon strip.
Once you have corrected the conditions that caused the fatal error, power-cycle the PLC or
perform a warm restart from STEP 7-Micro/WIN SMART. To perform a warm start, click the
Warm Start button
in the Modify area of the PLC menu ribbon strip.
Restarting the PLC clears the fatal error condition and causes power-up diagnostic testing. If
another fatal error condition occurs, the PLC sets the System Fault LED again; otherwise,
the PLC begins normal operation.
There are several possible error conditions that can render the PLC incapable of
communication, in which case you cannot view the PLC error code. This type of error
indicates a hardware failure requiring the PLC module to be repaired; it cannot be fixed by
changes to the program or by clearing the PLC memory.