嵌入式可编程逻辑控制器中加挂惠普图形语言的设计

Design of Integrating HPGL into ePLC

摘要:

为解决在PLC运动控制开发中难以融入CAD技术的问题,提出在ePLC中加挂HPGL的设计;通过HPGL指令到功能块的归一化,目标文件的压缩存储,层次化的内存分配,不同下载模式设置实现加挂的接口设计;采用三级线程抢占式调度算法,完成HPGL程序执行控制算法、功能块程序和紧急任务的线程分配;对直线、圆、矩形、螺旋线和非规则五种轨迹进行试验,试验结果均良好拟合CAD中轨迹,验证了该设计在直角坐标机器人控制中的可行性。

Abstract:

The design solved the problem of difficult to bring CAD technology into PLC motion control.Interface design,as the focus of the implementation,included HPGL instruction normalization,compression storage of the target file , hierarchical memory allocation,different download mode set. HPGL program execution control algorithm, function block and urgent task allocation were allocated in different levels. Tertiary preemptive scheduling algorithm was adopted to complete the task scheduling. After testing straight line, circle, rectangle, helix and the rules track , the results well fit trajectory in CAD.Verify the feasibility of the design in rectangular coordinate robot control.