Security is an important issue these days with homeowners. All new homes install security systems as a standard; some are simple systems, while others are complex. All security systems have one thing in common though; they alarm after a breach in security has occurred. They are reactive, not proactive. What is needed is a system that will prevent break-ins, thus creating a more secure home environment.
Most break-ins will occur at night, under the cover of darkness. A house that looks dark and unoccupied is a good target for a potential break-in. Some homes will put a timer on one of their lamps in the living room to make the house looked lived in. But this is a sure give away for the criminal element who will watch the house for a couple of days and see that the same light will go on and off at the same time each day. If it is possible to have the lights, throughout the house, go on and off automatically as they usually would when the homeowners occupied the house, the thief would have second thoughts breaking into that home.
Lighting control with a Programmable Logic Controller (PLC) will allow for this security feature. Security systems have optional programmable outputs to interface with other control systems. By programming one of these outputs to indicate when the security system has been armed and connecting this output to the PLC, gives the PLC the permissive to automatically turn various lights on and off throughout the home, giving the lived in affect. The reason to link the security system and PLC together saves the homeowner from having to turn two systems on and off every time they leave and come back home. Once homeowners put in their code to arm the security system, the PLC will automatically control the lights until they come back home from a vacation or an evening out.
Another security feature to consider is having all the lights in and outside the house blink off and on (or all steady on) when the security system goes into alarm. This would make it very difficult for the burglar to move about the home at night unnoticed by the neighbourhood. This feature could be achieved in the same manner as the armed scenario, using another one of the optional programmable outputs of the security system linked to the PLC. Even when the security system is not armed and the homeowners are at home, they would be able to turn all the lights on or off, inside and outside the house, from keypads located at the front and back door or from the bedside.
When the homeowner returns home at night, he or she needs to disarm the security system within a short time frame. This means they need to get access to the security panel and enter the security code to disarm the system. In most cases they need the lights on to see the security panel, so that they may enter the code correctly. If the lights over the security panel could come on automatically when they enter the door, this would assist the homeowner in disarming the security system. By connecting a door contact to the PLC input, and knowing that the security system is armed and that it is night outside, the light over the security panel would automatically come on. Only when all three of the above conditions are met would the PLC turn the light on, thus eliminating any nonsense switching of the light off and on.
Integrating the security system with the PLC lighting control system creates a more secure home environment, when the homeowners are away or at home.