Siemens SINAMICS S120 Series Function Manual page 175

The response returns the corresponding data set:
Table 6- 5
Value
MBAP header
03 h
04 h
11 h
22 h
33 h
44 h
Table 6- 6
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
Communication
Function Manual, 12/2018, 6SL3097-5BD00-0BP0
Device response to the read request, example
Byte Description
7
8 Number of bytes (4 bytes are returned)
9 Data first register "High"
10 Data first register "Low"
11 Data second register "High"
12 Data second register "Low"
Invalid read request
Communication via Modbus TCP
6.5 Write and read access using function codes
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)
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