Siemens SINAMICS Configuration Manual page 183

Table A-19
Read request
Invalid register address
Read a write-only register
Read a reserved register
Controller addresses more than 125 registers
The start address and the number of registers of an
address are located outside of a defined register block
Structure of a write request via Modbus function code 06 (FC 06)
Start address is the holding register address.
Via FC 06, with one request, only precisely one register can be addressed. The value, which
is written to the addressed register, is contained in bytes 10 and 11 of the write request.
Table A-20
Value
MBAP header
06 h
00 h
63 h
55 h
66 h
The response returns register address (bytes 8 and 9) and the value (bytes 10 and 11), which
the higher-level control had written to the register.
Table A-21
Value
MBAP header
06 h
00 h
63 h
55 h
66 h
Table A-22
Write request
Incorrect address (a holding register address does not exist)
Write to a "read-only" register
Write to a reserved register
For Exception Code 4, via the holding register 40499, you can read out the internal drive error
code, which has occurred for the last parameter access via the holding register.
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Invalid read request
Structure of a write request for device number 17, example
Byte Description
7 Function code
8 Register start address "High" (write register 40100)
9 Register start address "Low"
10 Register data "High"
11 Register data "Low"
Device response to the write request, example
Byte Description
7 Function code
8 Register start address "High"
9 Register start address "Low"
10 Register data "High"
11 Register data "Low"
Invalid write request
A.1 Communication
Inverter response
Exception code 02 (invalid data address)
Telegram in which all values are set to 0.
Exception code 03 (invalid data value)
Exception code 02 (invalid data address)
Inverter response
Exception Code 02 - invalid data ad‐
dress
Exception Code 04 - device failure
Communication
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