在主画面上添加两个画面窗口，对两个画面窗口--其他属性做一些基本设置

在主画面按钮（弹出A画面）--事件--添加C脚本

SetPropChar(lpszPictureName,"画面窗口1","TagPrefix","");//变量前缀，可以不做

SetPropChar(lpszPictureName,"画面窗口1","CaptionText","电机1");

SetPropChar(lpszPictureName,"画面窗口1","PictureName","A画面.Pdl");

SetPropBOOL(lpszPictureName,"画面窗口1","Visible",1);

在A画面按钮（弹出B画面）--事件---添加C脚本

SetPropChar("主画面.Pdl","画面窗口2","TagPrefix","");//变量前缀，可以不做

SetPropChar("主画面.Pdl","画面窗口2","PictureName","B画面.Pdl");

SetPropChar("主画面.Pdl","画面窗口2","CaptionText","连锁");

SetPropBOOL("主画面.Pdl","画面窗口2","Visible",1);

然后稍加完善可以实现