Resources / Networks / Modbus TCP

Modbus TCP

ModbusTCP functionality includes reading or writing to Modbus Holding Registers (4:xxxx registers in Modbus syntax).

Server

External ModbusTCP clients can have read/write access to your User Program Variables. You declare which of your variables can be accessed and the relative address offset from 4:0000 the data will appear.

*Please note that Modbus Holding Registers are 16 bit INT data type. If you select a variable that is a DINT data type, it will use 2 Holding Registers.

Client

Use the IP address of the host device to establish the client and receive information from that server. Choose which variables to read values for, or write variables for the server to read. Registers can be written as “1”, “2”, etc., since we have taken care of the more specific addressing for you.