I initially posted this in SuperUser SE Site, but it was recommended that I bring it here instead. So, here we go 🙂
We have a 'dated' security system at the office. It is a model that was made (or at least rebranded) by a company named ATI Access. The board are stamped as: SA-2000-II V8.0.
As I mentioned before, the company that made (rebranded) the board is "ATI Access", located 30 minutes away from me in Milwaukee, WI. As of a few weeks ago, they are now defunct. That means that all my tech support, etc, has gone out the window. With that being said, I am trying to have a go at a small project, but I am now flying blind. Here are the details:
On the top left side of the board, there are 5 inputs that can be programmed to do various tasks such as trigger an alert, or open a door by pushing a button. Looking at the manual for the board, a simple 'dry contact' switch is all that is needed to trigger them. So, what I have done on one of my panels is connect wires to Input 2 and attached them to a doorbell attached to the side of a table in my IT Closet. I then programmed the input to open the door on my IT Closet when the button is pressed. It works great. Go me, right?
Well, that is not good enough for me. I want to be able to control it with my PC as well. Now yes, I could just keep the security system open at all times, and alt-tab to it, right click on the door, and choose Open, but that is a lot of steps. I figured I would just write my own app that sits in the system tray that I can double click on, which would somehow emulate me pushing the doorbell.
I am not looking to use the PC to control a motor to push the doorbell for me, although that would be kinda cool. I am thinking that perhaps the serial or parallel ports could act as a dry-contact switch (however I am pretty sure that's not a feasible idea), or perhaps using some sort of dry contact relay that can be controlled via the serial port. So, the sequence of events would then be:
- Click on the icon of my app in the system tray
- App sends a signal out via the COM or LPT port (this part I can handle, I love programming)
- That signal is picked up by [insert stuff I don't know here] that trips the relay momentarily to a CLOSED position, completing the circuit to the security panel input header.
- Security Panel works its magic and opens my door.
As stated, I have this done the manual way utilizing a doorbell button, but I am looking to fancy it up and use my PC instead. Has anyone done here ever done something similar to this and is willing to point me into the right direction for [insert stuff I don't know here] ?
For bonus points: Does anyone have experience with this type of security panel? I'd be interested in knowing if there are any alternatives to the software that I am currently using for it (StarAccess Pro is the software that is used).
Best Answer
I recommend an Arduino board and any one of the many existing "relay shields" for it. Arduino connected via USB to computer is easily programmed to present a virtual COM port where you can send commands. Then you can close relay contacts by just switching an Arduino output pin from LOW to HIGH state.