Hardware Interrupts - Siemens SIMATIC Equipment Manual

5.3.3

Hardware interrupts

During a hardware interrupt, the CPU interrupts processing of the user program and
processes the hardware interrupt organization block.
For detailed information on the event, refer to the hardware interrupt organization block with
the "RALRM" instruction (read additional interrupt info) and to the STEP 7 online help.
The information on which channel of the I/O device triggered the hardware interrupt is
entered in the start information of the organization block. The figure below shows the
assignment to the bits of the local data double word 8.
Figure 5-2
I/O device digital inputs DI 16x24VDC M12-L 8xM12 (6ES7141-6BH00-0BB0)
Equipment Manual, 06/2021, A5E46570510-AB
Start information of the organization block
Interrupts/diagnostics alarms
5.3 Alarms
29