In Russia, according to the census, now about 65% of citizens live in high-rise buildings permanently. In large cities, this figure will be even higher. And what is the first way to control access to an apartment building? Of course, this is an intercom doorbell panel on the access door. The vast majority of these devices are analog audio call panels, models with the possibility of video shooting are much less common. The classic coordinate - matrix intercom at the entrance to the staircase and the tube in the apartment provides access control for several generations. In this way, the simple problem of two-way audio communication and opening the door is perfectly solved.
However, taking into account the development of high technologies, it would be strange not to take advantage of existing experience. Many firms have done so. Now the market has a large number of models of IP call panels. In addition to the basic tasks, this intercom is immediately equipped with a video module, the ability to call on several devices, recording video to the archive. A variety of hybrid, modular solutions, models in specialized, protected enclosures are offered. Manufacturers give the buyer a choice of complete set of the call panel, which allows to significantly expand its functionality.
The most versatile and scalable here is the use of SIP - intercoms that have all the advantages of IP devices. In addition, the concept of the Internet of things is satisfied - all SIP devices will work easily on the same network. Independent laboratory CCTVlab tested multi- subscriber SIP intercoms.
WHAT WAS TESTED
What do you expect to get from a high-quality outdoor video wall? In the first place - high-quality video signal, regardless of the time of day or background environment. Well and, of course, high-quality two-way audio communication - the basic functionality of any intercom. Thus, in the laboratory investigated the following functionality:
video quality in various conditionssound delay
HOW TO MEASURE
The viewing angle was determined by the actual field of view of each panel.Image resolution was measured by special tables:with normal lighting 500 lux.when illuminated from the built-in backlight when the light is off in the room.Shooting a person was carried out at a distance of 0.5 m from the panel:with normal lighting was carried out at 500 luxwhen illuminated from the built-in lighting was carried out on the street at night.at a counter flare in a frame from a powerful light source.The resulting time delays in the device were measured:between audio and videobetween the audio signal from the visitor to the operatorbetween the audio signal from the operator to the visitor.A brief assessment was made of the interface capabilities of each panel.
TEST RESULTS BEWARD DKS15102
It has the highest resolution in the test 1064 lines when illuminated with 500 lux and 1045 lines when illuminated from the built-in backlight. Possesses the viewing angle maximum in a test of 135 degrees. Also, the model is among the leaders in delay time 0.08 with video relative to sound, 0.2 with operator panel, operator panel with 0.13 s.
When shooting a visitor in the room, his face remains visible in normal conditions and in backlight. When shooting at night with built-in backlight, the image retains good detail.
The interface has a wide range of camera configuration and image. Present setting SIP, duration of the conversation, alarm events on the opening of doors, control opening doors, watching videos from the panel and control the speaker volume and others. It is possible to disable echo cancellation.