Siemens SIMATIC ET 200AL System Manual page 283

Figure 5-9
Hardware interrupt of digital and analog input modules, bytes x+4 to x+7
The figure below shows the structure of a hardware interrupt.
Figure 5-10
Note
Byte x+4
You will find the event type in the device manual of the module that triggered the hardware
interrupt.
IM 157-1 DP (6ES7157-1AA00-0AB0)
Equipment Manual, 08/2021, A5E32100641-AE
Interrupts, error messages, diagnostics and system alarms
Example of a diagnostics interrupt (part 2)
Structure as of Byte x+4 for hardware interrupt
5.2 Interrupts
33