Siemens S7-1200 Programming Manualline page 26

2 S7-1200/1500 Innovations
2.13 STOP mode in the event of errors
Error OBs:
OB80 "Time error interrupt" is called by the operating system when the
maximum cycle time of the controller is exceeded.
OB121 "Programming error" is called by the operating system when an error
occurs during program execution.
For every error, in addition, an entry is automatically created in the diagnostic
buffer.
Note For S7-1200/1500 controllers there are other programmable error OBs
(diagnostic error, module rack failure, etc.).
More information on error responses of S7-1200/1500 can be found in the online
help of the TIA Portal under "Events and OBs".
Programming Guideline for S7-1200/1500
V1.2, Entry ID: 81318674
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