Siemens SINAMICS G110M Function Manual page 140

Communication via RS485
5.4 Communication using Modbus RTU
The response returns the corresponding data set:
Table 5- 19
Value
11 h
03 h
04 h
11 h
22 h
33 h
44 h
xx h
xx h
Table 5- 20
Read request
Invalid register address
Read a write-only register
Read a reserved register
Controller addresses more than 125 registers
The start address and the number of registers of an
address are located outside of a defined register
block
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- 21
Value
11 h
06 h
00 h
63 h
55 h
66 h
xx h
xx h
138
Slave response to the read request, example
Byte Description
0 Slave address
1 Function code
2 Number of bytes (4 bytes are returned)
3 Data first register "High"
4 Data first register "Low"
5 Data second register "High"
6 Data second register "Low"
7 CRC "Low"
8 CRC "High"
Invalid read request
Structure of a write request for slave number 17, example
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"
Inverter response
Exception code 02 (invalid data address)
Telegram in which all values are set to 0.
Exception code 03 (invalid data value)
Exception code 02 (invalid data address)
Function Manual, 04/2018, FW V4.7 SP10, A5E34229197B AE
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