Siemens SIMATIC S7-1500 Manual page 78

Reactions to a diagnostic interrupt
The following happens when an event occurs that triggers a diagnostic interrupt:
● The ERROR LED flashes red.
Once you have remedied the error, the ERROR LED goes out.
● The S7-1500 CPU interrupts processing of the user program. The diagnostic interrupt OB
(e.g. OB 82) is called. The event that triggered the interrupt is entered in the start
information of the diagnostic interrupt OB.
● The S7-1500 CPU remains in RUN even if no diagnostic interrupt OB is present in the
CPU. The technology module continues working unchanged if this is possible despite the
error.
You can obtain detailed information on the error event in the error organization block with
instruction "RALRM" (Read additional alarm information), in the information system of
STEP 7 and in function manual Diagnostics
(https://support.industry.siemens.com/cs/ww/en/view/59192926), section "System
diagnostics in user program".
If the module is operated as a distributed module with PROFIBUS DP in an ET 200MP
system, you have the option of reading out diagnostic data with the RDREC or RD_REC
instruction using data record 0 and 1. You can find the structure of the data records in the
manual for the IM 155-5 DP ST interface module available for download on the Internet
(https://support.industry.siemens.com/cs/ww/de/view/78324181).
Technology module TM PosInput 2 (6ES7551-1AB00-0AB0)
Manual, 06/2018, A5E03982218-AB
Interrupts/diagnostic messages
5.2 Diagnostic alarms
77