INSTEON Garage Door Control with Interlock

A SimpleHomeNet INSTEON EZIO8T is used with Perceptive Automation's Indigo home control software to monitor and control three garage doors and three lawn irrigation zones. A hard wired interlock is incorporated to prevent the INSTEON system from opening the garage doors. This was done to eliminate the chance of a home control error exposing the house and garage to an open door when no one is home. The EZIO8T was choosen because it incorporated 3 inputs and 8 TRIAC outputs. The outputs can be used to directly control the irrigation zone valves and also directly control the interlock output relays. This post will focus on the garage door control interlock circuit.
WARNING: Do not build this control circuit unless you are willing to take the risk of the garage door accidentally closing on your head or on your children or on your car or anything else. Even if your garage door system has a interference detector at the floor, it could still hurt you if the door closes unexpectedly.
The interlock interrupts the output control circuit when the garage door is closed, preventing the EZIO8T output from operating the output relay. If the garage door is open, the EZIO8T momentary output operates the output relay which is wired to the garage door button circuits. See diagram.

The EZIO8T was purchased from machomestore.com and the relays were purchased from B and B Electronics. The 24VAC irrigation control transformer can be purchased at most builders supply stores.
Indigo was configured with an action group to operate the door if the door is open. This is just an additional interlock. A simple timer could be used to close the door after a fixed time of being open. The Indigo system here keeps track of who is home and has a timer that expires when no one has been home for a give period of time. If any of the garage doors are open, Indigo closes the doors and emails a message and webcam photo to assure the door is closed. Indigo also checks the doors at bed time and closes them if they are still open.

A diagram for the system using a SmartHome INSTEON I/O Linc with relays is also included below. Click the diagrams for PDF files.

A diagram for the system using a SmartHome INSTEON I/O Linc with a solid state interlock is shown below. Click the diagram for a PDF file. This design is much cheaper and smaller than the relay versions.