Siemens SINAMICS G120P, Руководство по эксплуатации

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Operation
6.8 Communication via RS485
Inverter cabinet units
238
Operating Instructions, 12/2014, A5E32923362A
The response returns the corresponding data set:
Table 6- 24 Slave response to the read request
Example
Byte Description
11 h
03 h
04 h
11 h
22 h
33 h
44 h
xx h
xx h
0
1
2
3
4
5
6
7
8
Slave address
Function code
Number of bytes (4 bytes are returned)
Data of first register "High"
Data of first register "Low"
Data of second register "High"
Data of second register "Low"
CRC "Low"
CRC "High"
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 Inverter response
Incorrect address (a holding register address does not exist) Exception code 02
Write to a "read-only" register
Modbus error telegram (exception code 04 - device failure)
Write to a reserved register