Siemens SIMATIC ET 200AL System Manual page 277

The figure below shows the structure of data record 1.
Figure 5-3
Reading data records
You have the option to read out data records 0 and 1 via SFC 59 (RD_REC) or SFB 52 (RDREC).
The data length of data record 1 is up to 240 bytes. In this case, data record 1 contains up to
38 channel fault entries.
Note the figures below in this section.
IM 157-1 DP (6ES7157-1AA00-0AB0)
Equipment Manual, 08/2021, A5E32100641-AE
Interrupts, error messages, diagnostics and system alarms
Structure of data record 1
5.2 Interrupts
27