Frame Structure - Siemens SIRIUS 3RW5 series Manual

3.3

frame structure

The data traffic between the client and the server and the corresponding answer from the
server to the client starts with the Address Field, followed by the Function Code. Following
this, the data (Data) are transferred. The structure of the Data depends on the function code
used. In the response telegram of the server to the client, the same Address Field and the
same Function Code are entered. The Data are filled according to the requested data.
● Address Field: This address is used to address a defined server on the bus.
● Function Code: Defines the server function requested with the telegram.
● Data = Telegram data: Function-code-dependent administration data and net data. When
transferring the register data, the high byte is always transferred first, followed by the low
byte, in accordance with the Modbus specification.
You will find more information on Function Codes in Chapter Function Codes (Page 51).
Exception Responses
You will find more information on exception responses in Chapter Error codes (Page 61).
SIRIUS 3RW5 Modbus TCP communication module
Manual, 03/2018, A5E43676481002A/RS-AA/001
Description
3.3 frame structure
23