I have a freePBX setup that I am planning to get an 8 port fxs card for. I want to use specific rings for certain purposes. for example when the dock door is picked up it goes directly to a voice menu and if you are pre authorized and put in your pin it rings you through to what ever you want. if you dont have a pin it rings the dock workers analog extension with a nonstandard ring to let them know its the door phone. Also I want to have an emergency ring to the ehs extension including analog ones.
I have poked around some and get an occasional hint that it might be possible but I havent found a how to on it yet.