顺序启动，每按一次启动按钮启动一台电机，I0.0为启动按钮，Q0.0----Q0.
IF "I0.0" AND "M0.0" = 0 THEN
    "Q0.4" := "Q0.3";
    "Q0.3" := "Q0.2";
    "Q0.2" := "Q0.1";
    "Q0.1" := "Q0.0";
    "Q0.0" := 1;
END_IF;
    "M0.0" := "I0.0";

逆序停止，每按一次停止按钮停掉最后启动的那台电机，I0.1为停止按钮，Q0.4----Q0.0
IF "M0.1" AND NOT "I0.1" THEN
    "Q0.0" := "Q0.1";
    "Q0.1" := "Q0.2";
    "Q0.2" := "Q0.3";
    "Q0.3" := "Q0.4";
    "Q0.4" := 0;
END_IF;
   "M0.1" := "I0.1";