Analog input
A PLC input that measures a continuous electrical quantity, usually voltage or current.
FIELD GLOSSARY
Words that make
the wiring clearer.
Short definitions, field context, and the distinction that usually matters five minutes later.
10 working terms
and growing
and growing
Common
The reference point shared by a signal and the input measuring it. Common does not automatically mean earth.
Hysteresis
The difference between a sensor's turn-on and turn-off points, useful for preventing chatter.
Loop power
The DC supply that lets a two-wire transmitter and its receiving input share one current path.
NPN
A sensor output that switches toward 0 V; commonly described as sinking output.
PNP
A sensor output that switches toward positive supply; commonly described as sourcing output.
Shield drain
A conductor connected to a cable shield to provide a controlled path for interference currents.
Sinking input
A PLC input arrangement that accepts current sourced by a PNP device.
Engineering units
The physical units represented by a signal, such as bar, °C, mm, or percent.
IO-Link
A point-to-point communication standard that adds configuration and diagnostics to a sensor connection.