Siemens SINAMICS V20 Operating Instructions Manual page 185

Start parameter request: Reading the parameter value of r0002 from slave number 17
Value
11 h 1
03 h
0258 h
0007 h
0010 h
xx h
xx h
Response for successful read operation
Value
11 h 1
03 h
20 h
0002 h
2F08 h
8001 h
0101 h
0301 h
001F h
xx h
xx h
Response for unsuccessful read operation - read request still not completed
Value
11 h 1
03 h
20 h
0001 h
2F00 h
0004 h
xx h
xx h
SINAMICS V20 Converter
Operating Instructions, 10/2019, A5E34559884-012
Byte Description
Slave address
2 Function code (read)
3,4 Register start address
5,6 Number of registers to be read (40601 ... 40607)
7,8 Number of registers
9 CRC "Low"
10 CRC "High"
Byte Description
Slave address
Number of following data bytes (20 h: 32 bytes ≙ 16 regis-
2 Function code (read)
3
ters)
4,5 40601: DS47 Control = 2 (the request was executed)
6,7 40602: Function code 2F h (47), response lengths 8 bytes
8,9 40603: Request reference mirrored = 80 h,
response identifier = 1 (request parameter)
10,11 40604: DO-ID = 1, number of parameters = 1
12,13 40605: Format, number of elements = 1
14,15 40606: Parameter value = 1F h (31)
16 CRC "Low"
17 CRC "High"
Byte Description
Slave address
Number of following data bytes (20 h: 32 bytes ≙ 16 regis-
2 Function code (read)
3
ters)
4,5 40601: Check value 1 = request is processed
6,7 40602: Function 2F h(47), response length 0 (fault)
8,9 40603: Error code:
still not been issued)
10 CRC "Low"
11 CRC "High"
Communicating with the PLC
7.2 MODBUS communication
0004 Response Not Ready (response has
183