Example Code for Modbus Assistant-RS485 Relay Control

Hardware Preparation

• DFR0545 LattePanda Alpha & Delta x 1
• DFR0779 RS485 Connector Expansion Shield for LattePanda Alpha&Delta x 1
• DFR0290 8 Channel IoT Ethernet Relay Controller (Support PoE and RS485) x1

Software Preparation

• Download driverDownload driver

Note: the driver needs to be installed when using on Windows for the first time. There is no need to install driver in Linux system.

Wiring Diagram

1. Plug the shield into LattePanda Alpha & Delta:

Connection graph

You need to use nylon columns and nylon screws to fix the expansion board and LattePanda.

Use ModBus debugging assistant

1. Repeat the above steps
2. According to the ModBus protocol rules of the 8-channel network control relay module, use the ModBus debugging assistant to send the correct instructions, then control the relay module.
3. Get the equipment name and control the switch of relay.