Design Of Communtcation And Interface For Automatic Gauge Control System Based On Single Chip Microcomputer

With the rapid development of China’s economy, the requirement of the quality andthe accuracy of board strips in various industries is increasing, but the equipment of manyiron and steel enterprises in our country is still backward, which leads to low qualityproducts, and can not meet industry needs. The renewal and modification of controlequipment are faced by these enterprises. An automatic gauge controller based onmicrocomputer was designed through comprehensive analysis about reversible coldrolling mill AGC system in this paper, which could be applied to replace those expensiveSiemens control equipment in the modification process.First of all, based on the requirement of reversible cold rolling mill AGC system, thePIC microcontroller was finally chosen with the main control chip of AGC mill controllerfor further development through the comparison among several series of microcontrollersin the paper. At the same time, the hardware circuits of the SCM﹑the A/D and D/Aconversion﹑the digital quantity input and output、encoder interface and thecommunication system have been devised, and the reasonable selection of the devices hasbeen completed, then the function of each module has been verified by the experiments.Secondly, according to the communication requirement when the rolling mill works,RS-485 was selected as the communication standard between the upper computer and thelower computer in the AGC system, and communication agreement is formulated throughprogramming. Considering the interference of industrial field, CRC check was used in thecommunication protocol so as to ensure the correctness of the transmitted data. As for theupper machine, VB6.0 was selected as the platform to develop the monitoring interface ofthe upper machine, which could correctly display the real-time transmission of the data,such as rolling force﹑entrance thickness﹑PID parameters and so on., realizing the goalof monitoring.Finally, aimed at the bad work condition of the rolling mill AGC controller and inorder to improve the reliability of controller effectively, the designs of hardware andsoftware were improved and perfected by the way of taking both the hardware and the software system into account.