The Research Of The Design And Application For Embedded Remote Terminal Unit

The Remote Terminal Unit (RTU) is a kind of remote measurement and control unit based on remote data acquisition and processing, data communication and control. It is an important part of the supervisory control and data acquisition (SCADA). The RTU based on the embedded processor is getting better to be hot spots of research, because of its low cost of hardware development, small size, low power consumption, good real-time features and short development cycle. The study of the RTU based on the research project "urban central heating integrated optimization control system" of the east real estate development company.Firstly, according to the technical requirements of the system design, the design of RTU includes the central processing unit, input/output module and data communication module, etc. The central processing unit used the embedded microcontroller STM32F103VET6for the control core, and the microcontroller can fully meet the designed requirements of the control system; The input/output module composed by the digital input/output, the analog input and the analog output module. The signal conditioning of the analog input and analog output adopt linear optical isolation device, which can realize the input and output of electrical signals between4-20mA; The data communication module includes the standard serial interface of RS232, RS485and GPRS module (MC35i), it can realize the function of remote wireless data transmission.Next, we adopt the modular design idea for realizing the program design of the data input and output, data processing, data communication and control algorithm module in turn.Finally, we used the designed embedded RTU to design a monitoring system of heat exchange station. It can realize the detection and remote transmission of the parameters. The parameters include the primary pipe network’s supply and return temperature, pressure, flow and the second pipe network’s supply and return temperature, pressure and flow. At the same time, it also completed the local control of the transducer and electric control valve. On the other hand, combined with the fuzzy adaptive control based on model reference, we realize the outlet temperature control of the heat exchange station. And the simulation results show that the fuzzy adaptive control based on model reference has several obvious advantages such as less overshoot, high precision and strong anti-interference ability.