Siemens SINAMICS G110M Function Manual page 132

Communication via RS485
5.4 Communication using Modbus RTU
Structure of a write request via Modbus function code 06 (FC 06)
Start address is the holding register address.
Via FC 06, with one request, only precisely one register can be addressed. The value, which
is written to the addressed register, is contained in bytes 4 and 5 of the write request.
Table 5- 15
Example
11 h
06 h
00 h
63 h
55 h
66 h
xx h
xx h
The response returns register address (bytes 2 and 3) and the value (bytes 4 and 5), which
the higher-level control had written to the register.
Table 5- 16
Example
11 h
06 h
00 h
63 h
55 h
66 h
xx h
xx h
Table 5- 17
Write request
Incorrect address (a holding register address does not exist)
Write to a "read-only" register
Write to a reserved register
For Exception Code 4, via the holding register 40499, you can read out the internal drive
error code, which has occurred for the last parameter access via the holding register.
132
Structure of a write request for slave number 17
Byte Description
0 Slave address
1 Function code
2 Register start address "High" (write register 40100)
3 Register start address "Low"
4 Register data "High"
5 Register data "Low"
6 CRC "Low"
7 CRC "High"
Slave response to the write request
Byte Description
0 Slave address
1 Function code
2 Register start address "High"
3 Register start address "Low"
4 Register data "High"
5 Register data "Low"
6 CRC "Low"
7 CRC "High"
Invalid write request
Inverter response
Exception Code 02 - invalid data
address
Exception Code 04 - device failure
Function Manual, 01/2016, FW V4.7 SP6, A5E34229197B AC
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