modbus_tcp_client

Overview

This example demonstrates how to use Modbus TCP protocol to control board LED light.

FreeModbus supports bellow feature:

  • Read coil(0x01)

  • Read discrete inputs(0x02)

  • Read holding registers(0x03)

  • Read input registers(0x04)

  • Write single coil(0x05)

  • Write single holding register(0x06)

  • Write board LED status(0x0d)

  • Read board LED status(0x0e)

  • Write multiple coils(0x0f)

  • Write multiple holding registers(0x10)

Running the demo

If the test passes, serial port output:

Please input Modbus Server ip address(for example 192.168.1.2): Note: don’t use backspace key or space key! Modbus Server ip: 10.91.20.33

Initializing PHY… [LINK STATE] netif=0, state=down [LINK STATE] netif=0, state=up, speed=100M_full

Modbus TCP example

FOR TASK ETH Get IP address from DHCP…

IPv4 Address : 10.91.20.66 IPv4 Subnet mask : 255.255.255.0 IPv4 Gateway : 10.91.20.254

Enable LED1 0 1 0 0 0 6 1 13 0 0 0 1 Enable LED2 0 1 0 0 0 6 1 13 0 1 0 1 …

Use the MIMXRT1180-EVK board as modbus Server simulator, write board LED status(0x0d) to control LED light

Supported Boards