In this experiment, the transmitter reads data from potentiometer to control the servo motor which is connected to the receiver. Simplex communication is unidirectional communication (one sends data and the other only receives data), with one arduino behaving only as transmitter and the other only as receivers. Simplex communication between two Arduinos by RS485 But in this project, we are only implementing simplex and half-duplex. RS-485 can be implemented into three types of serial communication system: simplex, half-duplex, and full-duplex. Data received by AB will be sent to RO pin that is connected to Arduino RX pin so the data can be read by Arduino. Electronic devices can exchange information through serial lines using the Modbus protocol. In order to be used as a receiver, RE pin and DE pin must be connected to GND, and RO pin is connected to RX. Modbus RTU Arduino PLC The Modbus RTU protocol is a means of communication that allows the exchange of data between programmable logic controllers (PLCs) and computers. Data is sent from Arduino TX pin to module DI pin, then data will be sent through AB.

To get the data from holding register to Arduino, I wanted to establish serial connection with data bit-format mentioned earlier. Furthermore, modbus is a serial communication protocol, developed for industrial applications, open and easy to deploy and maintain. The meter has RS485 channel to interface with external devices. In order to be used as a transmitter, RE pin and DE pin must be connected to 5V, and DI pin is connected to TX. The device is an energy meter which has various electrical parameters stored within the 'holding Registers' (Modbus RTU).

Modbus rtu arduino proteus