Siemens SIMATIC S7-1500 Manual page 33

Data record structure
The example in the figure below shows the structure of data record 64 for channel 0. The
structure of channels 1 to 16 is identical. 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
Digital output module DQ 16x230VAC/2A ST Relay (6ES7522-5HH00-0AB0)
Manual, 03/2015, A5E34934019-AA
B.1 Parameter assignment and structure of the parameter data records
Structure of data record 64: Bytes 0 to 3
Parameter data records
33