A.1.4.7 Communication Procedure - Siemens SINAMICS Configuration Manual

Table A-29 Response for successful write operation
Value Byte Description
MBAP header
03 h 7 Function code (read)
20 h 8 Number of following data bytes (20 h: 32 bytes
0002 h 9,10 40601: DS47 Control = 2 (request was executed)
2F04 h 11,12 40602: Function code 2F h (47), response length 4 bytes
8002 h 13,14 40603: Request reference mirrored = 80 h,
response identifier = 2 (change parameter)
0101 h 15,16 40604: DO-ID = 1, number of parameters = 1
Table A-30 Response for unsuccessful write operation - write request still not completed
Value Byte Description
MBAP header
03 h 7 Function code (read)
20 h 8 Number of following data bytes (20 h: 32 bytes
0001 h 9,10 40601: DS47 Control = 1 (request is processed)
2F00 h 11,12 40602: Function 2F h(47), response length 0 (fault)
0004 h 13,14 40603: Error code:
issued)
A.1.4.7 Communication procedure
Logical error
If the device detects a logical error within a request, it responds to the controller with an
"exception response". In the response, the device sets the highest bit in the function code to
1. If the device receives, for example, an unsupported function code from the controller, the
device responds with an "exception response" with code 01 (illegal function code).
Table A-31
Exception
code
01
02
03
04
Process data monitoring time (setpoint timeout)
The "Setpoint timeout" only applies for access to process data (40100 ... 40109, 40110 ...
40119). The "Setpoint timeout" is not generated for parameter data (40300 ... 40522).
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Configuration Manual, 08/2017, A5E36912609A
0004 Response Not Ready (response has still not been
Overview of exception codes
Modbus name
Illegal function code
Illegal Data Address
Illegal data value
Server failure
16 registers)
16 registers)
Remark
An unknown (unsupported) function code was sent to the
device.
An invalid address was requested.
An invalid data value was detected.
The device has terminated during processing.
Communication
A.1 Communication
187