Siemens SIWAREX WP241 User Manual

Communication
11.2 Communication via Modbus
SIWAREX WP241
Manual, 04/2014, A5E33713528A
165
11.2.6
Writing registers
If you wish to write registers from the data records DR 3 to DR 29, 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 DR 3 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 DR 3 is then updated in the Modbus memory.
● You can now write or change one or more registers with the corresponding variable. If
you wish to transfer the written/changed registers to the scale, it is necessary to write the
complete 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 SIWAREX module. 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 further command numbers in chapter → Command lists (Page 147).
In addition, an online document is available for working with SIWAREX WP231 and Modbus
→ Modbus communication of WP231
(http://support.automation.siemens.com/WW/view/de/77913998).
This document can also be applied when using a SIWAREX WP241 since the identification
mechanisms are identical.

Siemens SIWAREX WP241 Specifications

General

Brand	Siemens
Model	SIWAREX WP241
Category	Accessories
Language	English