Design And Implementation Of Remote Wireless Meter Reading System Based On Modbus Protocol

With the increasing of people’s living standards, using smart meters in the daily lives andwork is becoming increasingly popular. Traditional manual meter reading needs to consume alarge amount of manpower and material resources, and the meter reading staff need to visit thescene or in harsh environments. Therefore, in view of the considerations of safety andconvenience, the remote smart meter reading system came into being.In this thesis, we design a3G-based Modbus remote meter reading system, including Linuxserver, meter reading equipment and data acquisition equipment (RTU equipment). By usingModbus/TCP protocol, the Linux server exchange data with meter reading equipment, and useMySQL database to store meter reading data. Meter reading equipment chooses the embedded Linuxoperating system, using ARM9processing chips and Huawei EM770W3G module accessWCDMA networks.We use TCP/IP technology for data communication between the meter reading device andserver, to achieve Modbus/TCP protocol conversion. By using Modbus/RS485protocol, the datacommunication between the meter reading equipment and RTU devices bases on RS485.Meanwhile, the meter reading equipment completes the conversion between Modbus/TCP andModbus/RS-485protocol. We also adopt Linux script to complete the3G dial-up and PPPautomatically detects the network, which will automatic redial when Network outages or Pingbarrier. The whole meter system s data transmission adopts transparent transmission. Moreover,the meter reading equipment has a rapid detection of abort of the3G network, and redialsautomatically to ensure reliable communication with server.