Data Exchange with the SM 335
3-16
SM 335 – High-Speed Analog Input/Output Module for the SIMATIC S7-300
6ES7 335-7HG00-8BA1
3.3
Modifying SM 335 parameters with the help of system
function 55
HW Config
In RUN mode of the CPU, you can modify some parameters (dynamic parameters)
via system function 55.
For other methods of modifying parameters: see Reference Manual System Soft-
ware for S7-300/400 System and Standard Functions.
Parameters
The SM 335 parameters are 16 bytes long and are divided into two data records
(DR0 and DR1).
The SM 335 parameters (complete DR1 to be transferred to the module) must be
stored in a data area on the CPU (e.g., in a bit memory or data block). System
function 55 WR_PARAM is used to transfer the parameters to the SM 335.
Note
You must always initialize the SM 335 parameters with HW Config before
transferring them with system function 55.
Reason: The system function accesses SDB 1XX, which is generated with
HW Config.
Data Records
The SM 335 parameters are stored in two data records (DR0 and DR1).
Data Record 0 (DR0)
Data record 0 of the SM 335 is 2 bytes long and contains the static parameters of
the SM 335. You cannot modify these parameters with system function 55.
Data Record 1 (DR1)
Data record 1 contains the dynamic parameters of the SM 335. SM 335. You can
modify these parameters with system function 55.
The complete data record 1 (bytes 0 to 13) must always be transferred.
