A good night’s sleep in a smart home The KNX/EIB system allows for integration of important features related to security. Not only the alarm system can be coupled with the electric network, but also smoke detectors, flood sensors and other systems we had written about in the previous part. Signals from them, input to the system, allow to protect the house from damage, and reduce the effects of random events. Integration with the alarm system allows i. e. to automatically switch on the lights if an intruder is detected, and to automatically notify the police or site security. In our systems we use standard options of alarm systems (output from central unit informing on the state of sensors). Such a solution reduces costs and gives more options to provide security. Presence simulation and automatic door lock When the family is away on holidays, the house becomes an object of desire for burglars. The function of presence simulation markedly decreases the risk of an unpleasant surprise when everyone comes home. A special module 'records’ the activities of the family in the period before the trip (regarding lamps, blinds, music, etc.), and then 'plays it back’ when they are away. The effect is very convincing, because it simulates real activities which are different from day to day. One can choose which components should play a part in the simulation, so that no energy is wasted on i. e. the coffee machine. The automatic door lock with access control recognises any person entering or leaving the house. At the turning of the key signals can be sent out to many different devices to i. e. turn of all lights, shut the blinds, reduce the temperature.  Losing the house keys will not force the owner to change the lock, all one needs to do is remove access to the house for a particular key. The door lock cannot be opened/closed remotely, however one can remotely accept (or decline) access by a key. There exists also the option of using a fully automatic door with remotely opened locks (or operating using proximity access cards). Intelligent cameras Cameras placed at vital points of the building and outside can send the image to any selected TV (should the family be startled by something). It can also record the image upon movement detection by the camera. All of them are powered by safe 24 V DC voltage or use radio/infra red waves, eliminating the risk of electric shock and reducing the risk of fire of the electric installation – the power voltage cables run directly to lamps and outlets. This also, in effect, reduces electromagnetic emissions.