Pins
Supply voltage
Ground
Control signal (e.g. from micro-controller)
Normally closed
Common pin
Normally open
Attributes
“npn” (active-high) or “pnp” (active-low)
Operation
The relay is an electronic switch. When theIN pin is high / disconnected, COM is connected to NC (NC means normally closed).
When the IN pin is low, COM is connected to NO (NO means normally open).
Setting the “transistor” attribute to “pnp” inverts the logic: when IN is high, COM is connected to NO, and when IN is low / disconnected, COM is connected to NC.