Programmable controller with relay output, thyristor output, transistor output three kinds of forms. The output wiring into separate output and common output. When the PLC output relay or programmable logic controller plc thyristor action, the two outputs of the same number of turns. In different groups, and the voltage level can be different types of output voltage. However, the output in the same group only of the same type, the same level of power supply voltage. Since the output Plc high speed counting modules element of the PLC is encapsulated in a printed circuit board and connected to the terminal board, the load connected to the output element shorted If the burning of printed circuit board, therefore, the application of the fuse to protect the output element.