NC door contacts monitored by two systems?

[spyguy 0]

Greetings all and thanks for reading.

 

I'm relatively new to access control and have run into something that seems simple enough, but I'm having a hard time finding any information on the topic.

 

I have a small installation that includes a DSC wired alarm system, there is also a controlled door with dual mag locks, rex, and reader. The two systems are separate, and the access control was added long after the pre-wire. I have a set of door contacts installed for each of the doors, and have one pair of conductors running back to my data closet.

 

All of the cable for the reader and mag lock solution is in place, but missing a dedicated pair of conductors for a second set of door contacts. My customer would like to see door contact activity on his access control platform but I really don't feel like swimming through a sea of fiberglass insulation for one door contact.

 

I'm using a Mercury 1501 for the access control side of things. To the best of my knowledge, it's just looking for dry contact activity. I have to assume that the resistor in the alarm circuit would somehow play a role preventing this from being easy...lol

 

I'd really like to piggy back off of the alarm systems door contacts with the access control solution. Does anyone have a suggestion as to how I might accomplish this?

[Daryl733 0]

How sure you are that the contact on the door is not daisy chain to other contact in the alarm system ?

 

In my opinion, just install a separate door contact sensor. Less problematic and doesn't involve meddling in other separate system component that are currently working.

Door sensor is cheap. Some EMLock also have magnetic bond in them to detect closure, so you don't need extra contact sensor (still need the wiring though).

 

Even if you put in extra door sensor, you can put it near the EMLock, and check if the EMLock have extra pair of wire for wiring. Most time there should be spare wiring from the EMLock to the Controller.

[ssmith10pn 0]

You could bring the door contact back to a digital input and send it out on a digital output to the alarm panel.

 

They also make double pole contacts.

 

http://www.interlogix.com/intrusion/product/1078-1076-series

[thewireguys 3]

They also make double pole contacts.

 

That is how the professionals do it.

[ssmith10pn 0]

They also make double pole contacts.

 

That is how the professionals do it.

 

Yep.

We use the GE 1" DPDT recessed contacts.

[Davide 0]

great informations shared

[rossko 0]

In a situation like that, also talk to the intruder alarm guy. Many alarm systems are capable of "mirroring" an input contact onto an output wire or spare output relay.

You get your door contact indication without wiring or contact changeout; the intruder alarm is not compromised by messing with its existing parts.

[SATO1 0]

I think that It is looking like upgraded digital access control systems and This also differs from tradition door locks system.