Siemens SINAMICS Series Operating Instructions Manual page 545

Table 10- 49 Assignment of the Modbus register for general parameter access using DS47
Register Description
40601 DS47 Control
40602 DS47 header
40603 DS47 data 1
... ...
40722 DS47 data 120
Note
Limited value range
Modbus TCP registers have a maximum 16 bit width. The values of display parameters
(r parameters) cannot always be represented with 16 bits. In these particular cases, the
maximum value that can be represented is displayed.
• Unsigned: 65535
• Signed min: -32768
• Signed max: 32767
10.8.4 Read and write access using function codes
Function codes used
For data exchange between the controller and device, predefined function codes are used
for communication via Modbus.
The Control Unit uses the following Modbus function codes:
● FC 03: Holding register to read data from the inverter
● FC 06: Write single register to write to individual register
● FC 16: Write to multiple registers to write to several registers
Structure of a Modbus TCP message
Figure 10-56 Individual components, including the Modbus Application Header (MBAP) and function
SINAMICS DCM DC Converter
Operating Instructions, 12/2018, A5E34763375A
Access
R/W
R/W
R/W
R/W
code
10.8 Communication via Modbus TCP
Unit Scaling ON/OFF text
or Value range
- -
- -
- -
- -
Descriptions of functions
Data / parameter
- -
- -
- -
- -
543