The intercom is a device that is designed to maximize the possibility of unauthorized penetration into houses, apartments or another territory. Previously, this kind of equipment was called a negotiation-porch device (ROM), and this name is sometimes found in receipts for payment of housing and communal services.
Today, such equipment is presented in a wide range of a large number of companies, so it is sometimes very difficult to opt for a particular intercom model.
When choosing such a device, it should be noted that any, even IP-intercom, tested by time, must include a call unit, an apartment intercom, locks and keys. With the help of the call block, a call of the necessary apartment and communication with it are provided, and the negotiation device allows you to maintain a connection between the visitor and the tenant. Castles block the front door, and the keys allow the residents to open the locks. In addition, intercoms can be equipped with a separate power supply, emergency battery, switch and electronics unit.
Choosing an intercom device should be taken into account the conditions of its work and the requirements for it. Based on the features, such equipment is divided into symptomed and duplex, digital and coordinate. Duplex intercoms make it possible to keep in touch in both directions (similar to the phone). In this regard, telephone pipes as apartment negotiation devices are usually used in such equipment.
Symphlex systems allow you to communicate alternately in each direction. With this technology, modules with loudspeakers are used as apartment devices. At present, duplex type systems are mainly used.
As for the technological construction of such systems, digital intercoms are more reliable and easier to install and operate, since they involve the use of a two-wire cable. As disadvantages of such devices, experts note the higher cost of the tube compared to coordinate-type intercoms, since it contains an apartment call code decoder.
Coordinate-type systems are more complex and material-intensive, but due to the low cost of tubes, they are in considerable demand.
