PNP/NPN Signal Converter for Vision Lighting Integration
Toggle your camera or PLC output's signal type below to see how a PNP/NPN converter changes what reaches the light's Pin 4 — and whether you actually need one.
Camera / PLC Output
+24V when active (sourcing)
PNP ↔ NPN Converter
PNP → NPN
Light — Pin 4 (Trigger)
0V when active (sinking) at Pin 4
PNP vs NPN, Briefly
A PNP (sourcing) output switches its signal wire to +24V when active; an NPN (sinking) output instead pulls its signal wire down to 0V when active. Our lighting's Pin 4 trigger input must be wired to match whichever convention the upstream source actually uses — see our full M12 pinout guide for the wiring diagram.
Inside a PNP/NPN Converter
Most commercial PNP/NPN converters are small opto-isolated DIN-rail modules: the incoming signal drives an internal LED, and a phototransistor or relay on the output side re-creates the opposite sourcing/sinking behavior. Opto-isolation is worth paying for in an industrial environment — it breaks the electrical connection between the source and the light, so noise or a fault on one side can't propagate to the other.
When you probably don't need one
Before buying a hardware converter, check whether the source can simply be reconfigured: most modern smart cameras (Cognex, Keyence, Basler) let you set each output's polarity to PNP or NPN in software, with no extra hardware required. A physical converter is really only necessary for older fixed-polarity outputs, or PLC signals you can't safely reconfigure.
Ask Our Wiring Team
Tell us about your camera, controller or trigger setup and one of our engineers will help you wire it correctly.