Siemens Sinamics G120P Operating Instructions Manual page 238

Operation
6.8 Communication via RS485
The response returns the corresponding data set:
Table 6- 24
Example
11 h
03 h
04 h
11 h
22 h
33 h
44 h
xx h
xx h
Structure of a write request via Modbus function code 06 (FC 06)
Start address is the holding register address.
Using FC 06, precisely one register can always be addressed with one request. The value to
be written to the addressed register is contained in bytes 4 and 5 of the write request.
Table 6- 25 Write request and response of the inverter
Write request
Incorrect address (a holding register address does not exist) Exception code 02
Write to a "read-only" register
Write to a reserved register
238
Slave response to the read request
Byte Description
0 Slave address
1 Function code
2 Number of bytes (4 bytes are returned)
3 Data of first register "High"
4 Data of first register "Low"
5 Data of second register "High"
6 Data of second register "Low"
7 CRC "Low"
8 CRC "High"
Inverter response
Modbus error telegram (exception code 04 - device failure)
Operating Instructions, 12/2014, A5E32923362A
Inverter cabinet units