Triggering Of A Hardware Interrupt; Alarms; Diagnostic Alarms - Siemens SIMATIC ET 200MP Manual

Interrupts and diagnostic, error, and system alarms

5.3 Alarms

5.2.2

Triggering of a hardware interrupt

Triggering of a hardware interrupt
When a hardware interrupt occurs, the CPU interrupts execution of the user program and
processes the hardware interrupt OB. The event that triggered the interrupt is entered in the
start information of the hardware interrupt OB.
Note
Diagnostics "Hardware interrupt lost" (from I/O module)
Avoid creating hardware interrupts cyclically.
If the hardware interrupt load is too high, hardware interrupts can get lost depending on the
number of I/O modules and the communication load.
5.3 Alarms
5.3.1

Diagnostic alarms

Actions after a diagnostic alarm
There can be more than one diagnostic alarm at the same time. Actions initiated by
diagnostic alarms:
● The ERROR LED of the interface module flashes.
● Diagnostic data is reported as diagnostic interrupts to the CPU of the IO controller and
can be read via data records.
● Incoming diagnostic alarms are saved to the diagnostic buffer of the IO controller.
● The diagnostic interrupt OB is called. If the diagnostic interrupt OB is not available, the IO
controller goes into STOP mode.
You can find additional information in the STEP 7 online help.
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Interface module IM 155-5 PN ST (6ES7155-5AA01-0AB0)
Manual, 11/2017, A5E03612323-AC