Design And Implementation Of Automatic Water Temperature Station Based On The CANopen Protocol

The first condition of aquaculture farmers to get profit is to improve disaster prevention and mitigation capabilities and prepare to deal with changes in water temperature. The most important prerequisite for doing such work is to improve the accuracy of the forecasts. The fundamental purpose is to enhance the service of the defense capacity. Reliable water temperature observing system can provide us accurate data, which can give us an improtant guarantee to improve the prediction of forecast accuracy and service canabilities. In order to cope with the weather and climate changes, it is necessary to observe water temperature for a long-term and continuous and reliable time.Controller Area Network (CAN) bus and embedded system were used to build automatic water temperature station, in the automatic water temperature station’s application layer, CANopen protocol was used to achieve automatic detection of the water temperature. In the embedded system, ARM owned good control capabilities, powerful computing capability, low power consumption and good real-time. Therefore, ARM Cotex-M3was chose as the micro-control for the core of the system hardware platform, Base on this hardware platform, the automatic water temperature station system chose simple and practical CooCox CoOS to build an embedded operation system. The thesis used these platforms to design and implement the automatic water temperature station. The communication between master and slave though CAN controller which was not a stand-alone device, but a integrated micro-controller. It could be used to build a prowerful LAN and supported for distributed real-time control of a very high level of security.The thesis first introduced the status of the current water temperature measrements and described the characteristics of the automatic water temperature station which was designed in the thesis, and then analysised the advantages of the CAN bus and CANopen protocol. Base on these, the thesis achieved the automatic water temperature station’s software, hardware and protocol design. Secondly, on the basis of the overall system hardware design, the thesis achieved automatic water temperature station’s CAN controller peripheral interface circuit, and used the termination resistors to overcome the bus transmission interference. In the part of the temperature measurement hardware design, four-wire temperature measurement system and two standard reference resistors were chose to improve the accuracy of the temperature measurement system. Thirdly, by analyzed the basic principle of the CANopen protocol, the thesis completed Process Data Objects Communication,Server Data Objects communications, Network Management functions and HeartBeat monitoring functions, realized some communication functions of the CANopen protocol. Finally, the tests were done on the automatic water temperature station system. Tests showed that automatic water temperature station system can complete the cmmunication functions of CANopen protocol, and can measure water temperature accurately, it owned operability and practicability.