Modbus Function Code Overview - Grundfos CIM 200 Functional Profile And User Manual

8. Modbus function code overview

The supported function codes are shown in the table below:
Type
16-bit data (registers)
Diagnostics
Reading or writing coils is not supported.
The same data are available in both holding registers and input
registers, meaning that either function, 0x03 or 0x04, can be used
for reading data.
16
Code Hex Name
03 0x03 Read holding registers
04 0x04 Read input registers
06 0x06 Write single register
16 0x10 Write multiple registers
Diagnostics. Only supported by CIM 200 Modbus RTU.
08 08
See section for subcodes.
12.6 Diagnostics, 0x08