The proximity switch is also called a non-contact switch. As the name implies, the on/off state of the switch does not need to be performed by mechanical contact. As long as the detected body (such as metal) is close to the sensing range of the proximity switch, the state flipping can be changed from "on" to "closed". , or from "closed" to "open". Therefore, it is neither an active contact nor a passive contact.
A switch means on and off. It refers to an electronic component that can open a circuit, interrupt current, or cause it to flow to other circuits. The principle of the switch is that the "closed" of the contact indicates that the electronic contact is conducting, allowing current to flow; "open" means that the electronic contact is not conducting to form an open circuit, and no current is allowed to flow.