What is a video intercoms and their classification

In today's world, society is quite relevant is the issue of security, the protection of their personalof space from unwanted subjects and influences. Certainly, more personal space than a house, apartment, entrance, garden, garage unlikely to be found. The most common method now restrict access to the territory or premises, is the use of electronic locking devices - intercoms. This system of interconnectionsOF DATA elements, which allows through the use of electromagnetic lock to restrict access through the door. The kit includes all intercom subscriber units (outdoor, with a dial pad, and internal, with the unlocking device), switch and lock. By way of organizing communication through user devices, intercoms are audio-visual equipmenteo types. The first - a simple and cheap, providing only audio communication. - The subscriber unit, which in addition to audio, the video has the ability to translate from the installation site. Such a system is, of course, is much more expensive than a simple door phone, but instead has a lot more opportunities, as well as Propertyennuyu extended classification. As a rule, intercom with video calls are classified according to the following criteria:

• video signal type (black and white, color);
• type of audio communication (subscriber device with voice tube or without);
• UnitsETS video channels (1-, 2-, 3- and 4-channel). This criterion determines the number of possible screens to display the information, ie, determines the possibility of organizing the surveillance of small points.