Siemens SINAMICS G120P - Page 141

Communication via RS485
5.4 Communication using Modbus RTU
Fieldbuses
Function Manual, 04/2018, FW V4.7 SP10, A5E34229197B AE
139
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- 22 Slave response to the write request
Value
Byte
Description
11 h
0
Slave address
06 h
00 h
63 h
55 h
66 h
1
2
3
4
5
Function code
Register start address "High"
Register start address "Low"
Register data "High"
Register data "Low"
xx h
xx h
6
7
CRC "Low"
CRC "High"
Table 5- 23 Invalid write request
Write request
Inverter response
Incorrect address (a holding register address does not exist) Exception Code 02 - invalid data
address
Write to a "read-only" register
Exception Code 04 - device failure
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.