Dde is used to transfer the sampling data and the computed parameters as a result between pid parameters calculating program and rslinx which is the monitor of running plc in realtime . the pid parameters calculating process is programed with matalab languge and is called in win32 api programs by using the interface to c language . this method decrease the time of adjusting pid parameter and makes it possible to reduce the vibrating of steel belt 此外，为了实现对面涂烘烤炉内带钢悬垂状态的pid控制，本论文还借助dde (动态数据交换)技术完成了pid控制器参数整定计算程序和allen - bradley的上位机监控软件rslinx相互间数据交换， pid控制器参数整定计算程序的人机交互界面和dde通讯程序块用win32api编程实现，实现参数整定计算的程序块用matlab语言编程实现，通过matlab与c的接口在win32api程序中对其进行调用。
