3
Technical characteristics
The video door entry unit is nothing more than an audio-video interface through which it is possible to interact
with voice and images; the device is equipped with inputs and outputs that allow connections with all the other
devices in the system (power supplies, entrance panels, call buttons, video cameras, electrical locks, etc.).
Type of system.
The video door entry unit 5721 can be used only in Due Fili (Two-Wire) video door entry systems; it is therefore
necessary to use only devices in the Due Fili (Two-Wire) range (for the specifications please see the relevant
manuals).
The Two-Wire system enables the construction of systems with digital identification of devices and controls.
Each of the devices must be coded in order to have a unique code; each device communicates with the others
via data containing all the information relating to the management of the communication. The typical control
operations of a video door entry system are calls, opening electrical locks, switching on stair lights, etc.
Finally, as regards the type of cables to be used for connecting system components, both toward the pillar and
toward the speech unit, it is recommended to use the "2-wire twisted non-polarized" type with a cross-section
of 1 mm² art. 732H for indoor installations.
If laying underground in drainage channels, or in environments where regulations require using LSZH (or
LS0Z) cables you must use cable art. 732I.
In the system pillar there can be installed both Vimar and Elvox (VV, VE, CE) indoor stations, provided that
these belong solely to the Due Fili (Two-Wire) system range.
Advantages of the Due Fili (Two-Wire) system.
The most important advantage offered by the Two-Wire system, compared to other video door entry systems
(classic “8 wire + n” analogue or digital with multi-wire DigiBus) is its use in wiring the whole system with just
2 conductors, twisted and not polarized, on which the data, audio signal, video signal and necessary power
supply are conveyed to the connected devices.
Thanks to this characteristic, the system is therefore ideal to be used both in small-medium residential systems
and in large building complexes (up to a maximum of 200 indoor stations) because it considerably simplifies
the wiring operations.
Fig. 1 - Video door entry unit 5721
