*Updated information from RD: following information is not correct.
So let us put this article unpublished.
All GigE and USB cameras in GO series, have a PNP type Opt In trigger system. If you want to put a NPN type trigger source into these cameras, you need to add some circuit between camera and external device.
1. Convert NPN to PNP
In thie case, we will convert the external NPN circuit to a PNP circuit:
*Tr is short for Transistor.
2. Connect NPN directly to camera
In this case, we don't convert circuit type, but please note the current in external trigger device(Board) will be about 25mA when On.