Design And Implementation Of The Intelligent Instrument Based On CAN Bus

With the unceasing automation enhancement and unceasing expansion of production scale in industry control, the traditional independent measuring appliance already cannot satisfy the request which to the decentralization, the network and the intellectualized direction developed at present control system. So the intelligent measuring appliance based on the field bus arises at the historic moment. The field bus is the computer network in automation sphere. The CAN bus was one of the most competently field bus at moment and it has some merits just as good timeliness, high reliability and performance-to-price ratio, So it becomes now the hot spot in automated domain development, and obtained the widespread application. The research of intelligent measuring appliance system based on CAN bus has certain practical value.After analyzing and elaborating the related performance characteristic of the existing field bus and the technical specification and principle of CAN bus, this paper has designed the intelligent measuring appliance system based on CAN bus. This paper mainly has completed following several work:1) Using the 89C52 microprocessor which is the most popular microprocessor and combining with independent CAN controller SJA1000, it designed the Hardware circuit of the intelligent measuring appliance system. This system includes the intellectual node and the main node which has the CAN-USB transition function. Intellectual node has realized the data acquisition, the LED demonstration, CAN bus communication and output control. The main node has realized the date transition between the CAN bus and USB bus. This paper described the feasibility analysis, the whole control plan, the design principles and circuit diagram of each part of this intelligent measuring appliance system, and proposed the anti-jamming measure in the hardware design.2) According to the hardware circuit and function of the system, it has carried on the design of the software part and provided the software design flow diagram of each module and main code. It realized the purpose that the system operates steadily and reliably.3) It used the programming tool Microsoft Visual C+ + 6.0 to design the human-computer interaction monitoring management software on the monitor computer. This software was used to gather the data that USB uploaded, then it process and analyses the received date and send warnings. It used the traditional control algorithm (PID control algorithm) to adjust the data needs to output and control .Then it download the date to the intelligent measuring appliance through the USB interface and control the object under charge.The intelligent measuring appliance this topic designed has simple structure and flexible design and was easy to operate. It could satisfy the intellectualized development request in the industry control. It has the positive role to the research of the intelligent measuring appliance.