NPN Sensor Question

[Mr. Steve]

So as the build season comes to a close, theres one sensor we still have to track down. The sensor we're looking at has a NPN(actually Bipolar NPN/PNP) output, from other posts it looks like I can just hook this right up to a digital input, is that correct. (I'd rather double check now before I find out monday its not that way).

Assuming it was PNP, how would I wire it?

Thanks

[Al Skierkiewicz]

Mr. Steve,
The digital inputs to the RC have an internal "pullup" resistor to the internal power supply (+5 volts). The input is designed to have an input that closes to ground/common or is open circuit as the two states. The RC handles the rest.

[Chris_Elston]

Here you go, I have this on my industrial automation website. An explaination of NPN and PNP. It might help you see how they are wired different.

NPN-PNP (http://forums.mrplc.com/index.php?download=150)

I tried to upload it here, but it's BIGGER than 100 KB, and sorry you have to register to download it...that's just the rules of downloading.