Writing Registers - Siemens SIMATIC ET 200SP Operating Instructions Manual

6.32.6

Writing registers

If you wish to write registers from the data records DR03 to DR29, you must first export the
corresponding data record to the internal output buffer using an appropriate command.
Individual registers can then be written. The complete data record must subsequently be
written internally using an appropriate command. A plausibility check of the complete data
record is carried out in the process.
Example
A parameter from DR03 is to be written.
● First, write register CMD3_CODE with 2003 (2000 plus the number of the data record).
● Then write CMD3_TRIGGER with "1". The DR03 is then updated in the Modbus memory.
● It is now possible to write or modify one or more registers with the corresponding variable.
If you want to transfer the written/changed register to the scale, you need to write the entire
data record:
● First, write register CMD3_CODE with 4003 (4000 plus the number of the data record = write
data record).
● Then write CMD3_TRIGGER with "1".
● The data record is then transferred to the process memory in the electronic weighing
system. All registers of the data record are checked for plausibility in the process.
If the plausibility check fails, the complete data record is not written and a message is output to
the user (from the area of data/operator errors).
You can find all other command codes in section → Commands (Page 111).
A document for working with the electronic weighing system and Modbus is also available
online →Modbus communication of WP231
view/77913998).
Technology module TM SIWAREX WP351 HF
Operating Instructions, 01/2020, A5E47521010-AA
Parameter assignment/addressing
6.32 Communication via Modbus
(https://support.industry.siemens.com/cs/ww/en/
121