I am a software developer, and have implemented support for various digital I/O devices (via TCP/IP, such as ModBus). I am about to write some documentation for internal use, and the terminology being used around is kinda confusing.
These devices used ports that are either active low or active high (or, configurable to either). In some cases, "dry contact" and "wet contact" are being used. So, are these statements correct ?
Dry contact = active low = pull to ground to set HIGH
Wet contact = active high = needs a voltage to set HIGH.
