What is the difference between dry and wet contacts, as well as active and passive signals?
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1. What is a dry contact? What is a wet contact? For example, it is required that signals such as the DCS pump-shutdown signal, pump operation status indication, and pump fault status indication between the motor control center and the DCS system be provided to the DCS system in the form of dry contacts. What does this mean, and how is it implemented? 2. What is the difference between active signals and passive signals? Does \"passive\" mean dry contact? Does \"active\" mean a wet contact?
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Simply put: Dry contact means that the contact itself does not carry any electricity; it relies on an external power supply circuit to indicate whether it is connected or disconnected. Wet contact: That is, this contact or junction is equipped with an external power supply, allowing it to directly indicate either a connected or disconnected state. Active, meaning that the signal is powered, and the output signal does not require additional power at the receiving end. Passive, meaning that the signal also comes with a power supply; the output signal requires additional power to be obtained.