Design And Development Of Hydro-Valve Control System Based On RS-485 Bus

As one of important parts in hydraulic engineering system, the Hydro-Valve is used to regulate the water flow, control downstream water levels, discharge flood and remove sediments and floating materials. With the development of modern electronic technology, it's necessary to develop a highly reliable and remotely controlled Hydro-Valve control system with strong anti-disturbance capability.The developed Hydro-Valve control system in this paper includes two parts: the upper monitoring computer and the lower Hydro-Valve controller. The upper computer adopts an industrial PC to communicate with the lower controller through RS-485 bus, and thus to get the current position and set all parameters of the lower controller. The lower Hydro-Valve controller uses an absolute encoder as position sensor and integrates some functions such as measuring, display, control and data remote transferring. More than that, the lower controller realizes to control the opening of Hydro-Valve through electric relays by comparing the real and presetting position values of the valve.The developed software is made up of two parts. One is for the upper computer written in Visual C++ 6.0 and MSComm tools, and the other is for the lower Hydro-Valve controller written in Keil C. A RS-232/RS-485 converter is used as the reliable interface between the upper and the lower. The lower controller codes consist of modules such as the data storage, the keyboard interpreting, the LED display, 4-20 raA D/A conversion and the communication networking based on RS-485 bus.The experimental results have demonstrated that the hardware of the Hydro-Valve control system is feasible and its software is reliable. The controller possesses good performance, high precision, strong anti-disturbance and can be operated conveniently. Therefore the paper has achieved the designated aims.