Agricultural Monitoring System with Zigbee Network and PLC based on Modbus RTU Protocol

This paper presents the implementation of agricultural monitoring system with Zigbee network. An indoor server has been constructed to monitor and record the transmitted data from two weather stations, which placed in different area in agricultural field. Programmable logic controller (PLC) is used as main controller in indoor server, interfacing with Xbee module as coordinator supported by Arduino to make the wireless communication achieved. The weather station are formed by Arduino, Xbee module as RFD (reduced function device) and different sensors. It can be measured the temperature, humidity, soil moisture and wind speed. All devices in the weather station are powered by solar charging system. The proposed system uses Modbus RTU protocol to collect the data on the Zigbee wireless network. Experimental results shown that the proposed system is suitable for monitor and record the environmental parameters. The system has high reliability, stability, low cost and low power consumption. The distance to communicate the data between indoor server and each weather station using Zigbee wireless is up to 200 meters.