First, the output mode selection (1) Relay output: The advantage is that different AC and DC loads can be used between different common points, and the voltage can be different. The load current can reach 2A/point; but the relay output mode is not suitable for high-frequency action load. This is determined by the life of the relay. (2) Thyristor output: With load capacity of 0.2A/point, it can only carry AC load, can adapt to high frequency action, and the response time is 1ms. (3) Transistor output: The biggest advantage is that it is suitable for high-frequency operation, and the response time is short, generally about 0.2ms, but it can only carry DC5-30V load, the maximum output load current is 0.5A/point, but every 4 points Must not be greater than 0.8A. When your system output frequency is less than 6 times per minute, the relay output should be preferred because of its simple circuit design, anti-interference and strong load capacity. When the frequency is below 10 times/min, either the relay output mode or the plc output can be used to drive the Darlington transistor (5-10A) to drive the load. Second, anti-interference and external interlock When the PLC output has an inductive load, the load will cause a surge current impact on the PLC output. For this reason, the DC inductive load should be next to it and connected to the free-flow diode. The AC inductive load should be connected to the surge absorbing circuit. , can effectively protect the PLC. When the outputs of the two physical quantities have been interlocked within the PLC, interlocking should also be performed outside the PLC to enhance the reliability of the system. Third, the choice of COM points Different PLC products have different "COM" points. Some "COM" points have 8 output points, some have 4 output points, and there are 2 or 1 output points. When there are many types of loads and the current is large, a PLC product with 1-2 output points at "COM" point is used; when there are many loads and the types are small, a "COM" point is used. Indoor Led Display,Indoor Advertising Led Display Screen,Indoor Led Screen,Led Screen Indoor ShenZhen Megagem Tech Co.,Ltd , https://www.megleddisplay.com