Examples: Read Parameter - Siemens SINAMICS S120 Function Manual

Communication
11.4 Communication via MODBUS TCP
11.4.6.2

Examples: Read parameter

Table 11- 28 Write parameter request: Reading parameter value of r0002 from device number 17
Value Byte Description
MBAP header
10 h 7 Function code (write multiple)
0258 h 8,9 Register start address
0007 h 10,11 Number of registers to be read (40601 ... 40607)
0E h 12 Number of data bytes (7 registers, each 2 bytes = 14 bytes)
0001 h 13,14 40601: DS47 Control = 1 (activate request)
2F0A h 15,16 40602: Function 2F h (47), request length 10 bytes (0A h)
8001 h 17,18 40603: Request reference = 80 h, request identifier = 1 h
0101 h 19,20 40604: DO-Id = 1, number of parameters = 1
1001 h 21,22 40605: Attribute, number of elements = 1
0002 h 23,24 40606: Parameter number = 2
0000 h 25,26 40607: Subindex = 0
Table 11- 29 Start parameter request: Reading parameter value of r0002 from device number 17
Value Byte Description
MBAP header
03 h 7 Function code (read)
0258 h 8,9 Register start address
0007 h 10,11 Number of registers to be read (40601 ... 40607)
0010 h 12,13 Number of registers
Table 11- 30 Response for successful read operation
Value Byte Description
MBAP header
Number of following data bytes (20 h: 32 bytes ≙ 16 registers)
03 h 7 Function code (read)
20 h 8
0002 h 9,10 40601: DS47 Control = 2 (the request was executed)
2F08 h 11,12 40602: Function code 2F h (47), response lengths 8 bytes
8001 h 13,14 40603: Request reference mirrored = 80 h,
response identifier = 1 (request parameter)
0101 h 15,16 40604: DO-ID = 1, number of parameters = 1
0301 h 17,18 40605: Format, number of elements = 1
001F h 19,20 40606: Parameter value = 1F h (31)
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Function Manual, 11/2017, 6SL3097-4AB00-0BP5
Drive functions