PLC switch input

In general industrial control occasions, PLC is a frequently used controller, and its working voltage is almost 24V. This voltage cannot be directly connected to the input contact of the card we use. For industrial applications, in this case Usually use the optical coupler as the input repeater, let the 24V voltage signal transmitted to the contact through the coupler, can reach the protection contact and general industrial control occasions, PLC is a frequently used controller, which is used The working voltage is almost 24V. This voltage cannot be directly connected to the input contact of the card we use. For industrial applications, in this case, an optocoupler is usually used as an input repeater to allow 24V voltage signals. Through the coupler to transmit to the contact, the purpose of protecting the contact and the subsequent adapter card can be achieved, and there is no need to change the voltage range used to adapt to the card. PLC switch input signal types: DC input module, AC input module, AC and DC input module. The power supply for the input signal of the DC input module can be provided by the user, and the power supply for the DC input signal +24V can also be provided by the PLC itself. Generally, 8 inputs share a common terminal, and the field input provides a pair of switching signals: '0' or '1' '(With or without contact); each input signal is photoelectrically isolated, filtered, and then sent to the input buffer to wait for the CPU to sample. Each input signal has an LED display to indicate whether the signal reaches the input terminal of the PLC. AC input module input signal 100V (AC) ~ 240V (AC), the price is more expensive, the application is less, you can use the intermediate relay to convert.