Siemens SINAMICS V90 Operating Instructions Manual page 230

Control functions
7.7 Communicating with the PLC
The table below formats a response for successful read operation.
Byte Description
Header
01 h 0 Slave address
Number of following data bytes (20 h: 32 bytes ≙ 16 registers)
03 h 1 Function code (read)
20 h 2
User data
0002 h 3,4 40601: DS47 Control = 2 (request was executed)
2F0E h 5,6 40602: Function code 2F h (47), response lengths 14 bytes (0e h)
8001 h 7,8 40603: Request reference mirrored = 80 h,
response identifier = 1 (request parameter)
0202 h 9,10 40604: V90 = 2 h, number of parameters = 2
0301 h 11,12 40605: Format, number of elements of the first parameter
0001 h 13,14 40606: First parameter value = 1
0801 h 15,16 40607: Format, number of elements of the second parameter
4142 h 17,18 40608: Second paramter value = 12.15 (41426666 h)
6666 h 19,20 40609: Second paramter value
Write the PLC command from registers 40601 to 40609:
The table below formats a response for unsuccessful read operation (read request still not
completed).
Byte Description
Header
01 h 0 Slave address
Number of following data bytes (20 h: 32 bytes ≙ 16 registers)
03 h 1 Function code (read)
20 h 2
User data
0001 h 3,4 40601: Check value 1 = request is processed
2F00 h 5,6 40602: Function 2F h(47), response length 0 (fault)
0004 h 7,8 40603: Error code:
issued)
230
0004 Response Not Ready (response has still not been
SINAMICS V90, SIMOTICS S-1FL6
Operating Instructions, 09/2016, A5E36037884-002