Siemens Simatic S7-1500 CPU 1512C-1 PN User Manual page 139

Hardware interrupt
The compact CPU can generate a hardware interrupt for the following events:
● Rising edge
● Falling edge
You will find detailed information on the event in the hardware interrupt organization block
with the "RALRM" (read additional interrupt information) instruction and in the STEP 7 online
help.
The start information of the organization block includes information on which channel
triggered the hardware interrupt. The figure below shows the assignment to the bits of
double word 8 in local data.
Figure 6-5
Structure of the additional interrupt information
Table 6- 14 Structure of USI = W#16#0001
Data block name
USI
(User Structure Identifier)
The channel that triggered the hardware interrupt follows.
Channel
The error event that triggered the hardware interrupt follows.
Event
CPU 1512C-1 PN (6ES7512-1CK01-0AB0)
Manual, 12/2017, A5E40898741-AA
Start information of the organization block
Contents
W#16#0001
B#16#00 to B#16#0F
B#16#01
B#16#02
Comment
Additional interrupt information of the hardware
interrupts of the digital on-board I/O
Number of the event-triggering channel (chan-
nel 0 to channel 15)
Rising edge
Falling edge
Interrupts/diagnostics alarms
6.2 Interrupts and diagnostics
Bytes
2
1
1
139