Remote monitoring application based on Modbus and China unicom 3G

In China traditional methods of building Modbus remote monitoring system have some drawbacks. They are tightly dependent on telephone lines if wired communication was used; transferring speed is limited when using wireless technology like GPRS; Proprietary interfaces make it hard to reuse software design and new information island may be formed. So a new architecture for Modbus remote monitoring application was presented by this paper to solve the problems. 3G Gateway provides Modbus network with Internet accessing capability. Process data can be sent to LAN Gateway through 3G Gateway. LAN Gateway gets the process data and forward to OPC server. Then remote monitoring applications can read/write data from/to OPC server easily using standard OPC interfaces. A prototype system was implemented in laboratory. The system is in initial phase now, but it proved the technique feasibility of the architecture.