Siemens SIMATIC ET 200AL System Manual page 280

Interrupts, error messages, diagnostics and system alarms
5.2 Interrupts
Diagnostics interrupt, starting at byte x+8
The figure below shows the structure of the diagnostics interrupt starting at byte x+8.
Figure 5-6
Diagnostics interrupt from the modules, starting at byte x+14
The channel error entries start from byte x+14. A channel fault entry is 6 bytes long and can
follow 8 times starting at byte x+14.
If you read the channel faults with an SFB or SFC, then 38 channel diagnostics are possible.
Figure 5-7
30
Structure starting at byte x+8
Structure starting from byte x+14
IM 157-1 DP (6ES7157-1AA00-0AB0)
Equipment Manual, 08/2021, A5E32100641-AE