[asterisk-users] opening Doors with Asterisk!?

[Norman Franke]

On Aug 19, 2008, at 1:44 AM, asterisk-users-request at lists.digium.com  
wrote:

> i read a few articles online about the possibility to setup a  
> "buzzer" door system to PBX using asterisk!


I took a somewhat unique approach, based on reading recent postings.  
We already had intercoms without door relays. So, I bought a  
Grandstream GXW-4008 (8-port FXS) which supports loop current  
disconnect (often called CPC). My intercoms need this, and I found out  
that our Linksys PAP2Ts cannot do this. (Only for incoming calls,  
which is rather useless here.)

To open the relay, I bough a USB-IIRO-8 from ACCES I/O Products. It  
provides me with 8 relay closures (and 8 inputs, which I'm not  
currently using.) I wrote a very simple C app to close a relay based  
on command line parameters (relay number and duration.) I have an  
extension in Asterisk use the System dialplan command to open the door  
with our existing door latches through our HAI control system (which  
provides the delay to keep it open for 6 seconds or until it opens.)  
It's extremely fast and reliable. I run the phone and relay through  
the same Cat 6 cable.

We are only using 3 doors for now, but I can go up to 8, of course,  
with this setup.

Norman Franke
Answering Service for Directors, Inc.
www.myasd.com