Design of intelligent transmitter for pulp consistency based on the CAN bus technology

With its direction to decentralization, network and intelligence, field bus control system based on CAN has been applied more and more widely to the industrial control field. Aimed at solving the problems in the controlling process of pulp concentration based on analog instruments such as low precision and stability, high power consumption and excessive maintenance cost, an intelligent transmitter with CAN bus communication function is proposed here for pulp consistency control system. It can measure temperature, pressure and differential pressure signals. Methods to design the hardware and software of the transmitter are particular introduced. The hardware comprises industrial PC, single-chip MSC1211Y5, controller SJA1000 CAN and transceiver 82C250 CAN, which can realize the detection, conversion, calculation and communication of pulp concentration parameters. A main routine and a sending/receiving subroutine flow diagram on CAN communication are given in the paper. The system has features of simple structure, good applicability, low energy consumption, high reliability and strong anti-jamming ability and other advantages.