Nx650 with external contact

[snakevargas]

I'm trying to get nx650n wireless sensors to work using an external contact. As per the instructions, I removed the jumper, and connected a NC plunger contact in series with a 4.7k eol resistor. However, the sensor is always reading open, regardless of whether the contact is closed.

I tried a second nx650 and wired the resistor directly across the external contact terminals, with the same result.

The sensors work fine when used with their internal reed switch (and jumper installed), so it's not a wireless reception issue.

I'm using an elk m1 gold.

Any ideas on what I'm doing wrong?

 

[RAL]

This might be a long shot, but have you checked the resistance value of the EOL resistor with an ohm meter to make sure it is really 4.7k? 

 

[snakevargas]

Solved the problem after some googling (which led me back to this very forum). Turns out I had to enable option 1 and option 2 for the transmitters on the elk. Option 1 is supposed to disable the reed switch and option 2 switches the external contact to NC mode.

I'm somewhat perplexed at why there is both a jumper and a software option. I'd have expected the jumper on the nx650 to be sufficient.

 

[Del91574]

Nope.

Remember the Caddx (now GE) wireless was originally engineered by ITI. They were/are learned into those panels in "alarm" state, not normal state, so in their specific case, the connected sensor can actually be NO or NC as determined by when the sensor is learned in. 
 
Now Elk comes along, originally it didn't support ANY RF, then the first was the 448 and later 548E Caddx/GE receivers, then the later units. The coding and programming options were engineered after the fact with products that the M1 was originally supporting, only accepting the protocols from that 3rd party hardware.