Erik,
So the proposition seems to be:
Can I connect into a closed-loop system, and tap the tbd line that indicates the remote MD device has detected an "intrusion"?
Given:
The sensor isn't set up to signal another device.
There isn't an "alarm out" set of dry contacts [NO, COM, NC]
Then:
Can you find a signal to connect to the NVR to use as an alarm input?
Me:
I wouldn't want to fry the alarm input line to the NVR
The NVR costs more than the $50 MD sensor
My time isn't free. So figuring out a "hack" to use the $50 sensor means I won't spend too much time on it.
Esp given the risk that experiments could hurt the NVR.
And the idea a relay could be used between the NVR and MD sensor? More $, more head scratching, and experimentation....
My likely decision:
I'd shy away from the whole proposition.
Throwing good money after bad....
With risk to the NVR.
Possible Hack:
The device provides a "Unique sound and light pattern on the base unit identifies which sensor has been triggered."
You could have a camera that fills the FOV with the base unit. When the lights go active, you get an MD event.
But now, you're using a cam (investment) to utilize a $50 MD device.
And you'd have to fiddle and dink with getting the Rude Goldberg contraption to work.
Fastb