Siemens SIMATIC S7-1500 Manual page 53

Data record structure
The figure below shows the structure of data record 0 for channel 0 as an example. The
structure is identical for channels 1 to 7. The values in byte 0 and byte 1 are fixed and may
not be changed.
Enable a parameter by setting the corresponding bit to "1".
Figure B-1
Analog input module AI 8xU/I/RTD/TC ST (6ES7531-7KF00-0AB0)
Manual, 09/2016, A5E03484864-AD
B.1 Parameter assignment and structure of the parameter data records
Structure of data record 0: Bytes 0 to 6
Parameter data records
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