PLC may be interfered by outer factor to cause the confused program, then generate the false input and the error output, and cause the control facilities out of control and false action.

• 摘要可编程控制器会受到外部因素的干扰，造成程序误变或运算错误，从而产生误输人而引起误输出，使控制设备失控和误动作。