Software And Reliability Design On Intelligent Measuring And Controlling Module Of New DCS

DCS is one kind of control system which controls distributedly. It is one of the hottest topics in automation field while the industrial product increasing ceaselessly. It has been applied more and more widely and has become the mainstream in the controlling field. As a developing system,it is promoted by the applications of many new technologies, such as Computer Technology, Communications Technology, Fieldbus and Industrial Ethernet. After the combination with those technologies, it is more competitive with a new model of structure.Fieldbus is one kind of communication network that is used between local meter and control system. It is whole scattered, bi-directional and interconnected. CAN BUS is one kind of Fieldbus which is widely used in Automation Electronics. It is applicable in the field of Process Control, Robot, Sensors and so on. CAN BUS has many advanced characteristics such as low cost, high reliability, real-time, anti-interference, etc, which make it a good prospects.The thesis designs the intelligent measuring and controlling modules which is based on analyzing the working theory and the implementation of CAN BUS. We mainly research and develop seven kinds of intelligent measuring and controlling modules in the control station based on Industry Ethernet and Fieldbus Technology. They cooperate with the main control template and CAN BUS, realize input and output of the locale signals, complete kinds of control arithmetics such as data collection, linearization, fault detection, etc.There are many kinds of modules such as digital input templates(DI), digital output templates(DO), standard analog input templates(AI), standard analog output templates (AO), thermo-resistance signals input templates(RTD), thermocouple signals input templates(TC), etc. The modules have many functions such as signal collection, data management, fault alarm, signal drop detection and so on. Each module has been isolated and it meanwhile automatically diagnose the fault.Templates' software design includes the design of measurement and communication program, linearity arithmetic, room temperature compensation arithmetic, etc.Its function and capability will directly affect the usability, real-time capability, maintainability and reliability of the system.CodeWarrior software is used in the development and debugging of templates, which is embedded application development software tool to all MCU and DSP of Motorola (Freescale) in Metrowerks company. Reliability refers to products' capacity to complete the function in some condition and a period of time. Many technical measures have been used to improve the reliability of the intelligent measuring and controlling modules because of the bad industrial conditions. Redundant is one of the most important aspects of reliability design, so we conduct a comprehensive redundancy design for both hardware and software system. In addition, we have designed the format of CAN communication and achieved reliable communication.Finally, the experiment concerned about the modules is processed basing on the theoretical analysis, and the results prove that the design of the system is feasible.