PIR's and Alarm Input Functionality

I'm trying to understand how most contemporary NVR's (or alarm panels) work in regards to alarm inputs. Specifically, I'm trying to understand whether or not the alarm condition triggered at the NVR (coming from a PIR, for example) is based on voltage input, or is based ONLY on the state of N.O. (normally open) or N.C. (normally closed). If a PIR is wired to the alarm input (N.O. in my case, using a Swann NVR 7200-, will the NVR interpret a momentary "closed" circuit as an input signal simply by having the "circuit" closed, or does there also need to be voltage sensed when the N.O becomes Closed due to a PIR signal?

Thank you!

I looked at your manual and it's clear as mud.

I assume they are dry contacts.

1,2,3,4 are your alarm inputs and 5 is your common.

Around page 25 it says you can configure those inputs to be either NO or NC. Your choice.

As a test take a short piece of wire and terminate it to 1 and 5. Configure the input to be NC. The remove the wire and see if it goes into alarm.

I think you're looking at the four channel manual, because my manual has this information around page 44. But you're right, I can configure any alarm input as normally open or normally closed.