Comparison Commax CDV-72UM vs Kocom KVR-A510

The presence of a built- in quadrator in the intercom.

Quadrator is a device for simultaneous display of video signals from several surveillance cameras; the screen is divided into "tiles", each of which shows a picture from its camera. This allows the user to monitor the cameras without switching or missing "pictures" from any of them, and if necessary, the desired "tile" can be displayed on the entire screen. The simplest quadrators are designed for 4 cameras, however, there are solutions for more — depending on the number of cameras for which the intercom is designed (see below).

Note that a video intercom without this function can be supplemented with an external quad, but it is easier and cheaper to purchase a model where the quad is initially provided in the design.

— Android OS. The advantages of the Android OS include flexibility, which allows you to install third-party applications, thereby increasing the functionality of the device. Such applications may include SIP phones, programs that allow video surveillance, and others. But it is worth noting that such devices are not very suitable for the role of using a full-fledged tablet; firstly, most have a stationary location, and secondly, as a rule, the power of intercoms is not so high. Also, various restrictions may be set separately by the manufacturer; this must be clarified separately.

— Wi-Fi module. The Wi-Fi wireless communication module is found only in IP intercoms(see “Device type”). This function allows the device to connect to the network wirelessly - this is much more convenient than pulling cables, and the quality of communication is usually indistinguishable from a wired one. Another option for using Wi-Fi is a direct communication to a smartphone or tablet and using such a gadget as a remote control with an external screen; however, such an opportunity is provided relatively rarely.

- Mobile app. This feature means that the device can be operated via a smartphone or tablet with a special application installed on it. Such applications are usually released immediately for both of the most popular mobile operating systems today - Android and iOS; ho...wever, it would not hurt to clarify this point separately. In any case, control from a mobile device can have very extensive functionality (including even the ability to work via the Internet, in some models); and interacting with a device through a gadget that you can always keep with you is definitely more convenient than going to an intercom or other stationary equipment every time.

— SIP protocol. The intercom's support for the SIP protocol allows the intercom to redirect the signal from the calling panel through the telephone network to a mobile device, a stationary PBX or a computer with the appropriate software. Such a function may be useful, for example, in an office where there are a lot of visitors, and going up to the intercom every time to answer is inconvenient. Additional SIP capabilities in different models may vary significantly; they should be clarified separately.

- DVR support. The ability to operate the intercom in video recording mode from calling panels or from separate surveillance cameras. In most of these models, recording is not carried out constantly, but only when the call button is pressed or another event occurs - for example, a motion detector is triggered (see below). Video is most often saved to a memory card (see “Card Reader” below). In any case, this function allows you to find out who called the intercom at “inopportune hours”; it can also be useful in other situations - even to restore the picture of an emergency that came into view of the cameras.

— Internal communication (Intercom). This function allows you to make calls between intercoms on the same network. Depending on the implementation and settings, there is an addressable intercom, when you enter the number (identifier) of the device on the network to which you want to make a call, as well as options for setting up a general call, when the call goes to all devices on the network. In any case, this function will be useful if there are several intercoms in the network, so you can call, for example, a neighbor.

- Speakerphone. A hands-free function similar to that found in telephones. In this mode, a loud speaker and a sensitive microphone are used for conversation, located in the intercom body and allowing you to communicate comfortably at some distance from the device (up to a meter, or even more). This function is especially important for models with a handset (see “Execution”) - it allows you to talk without holding the handset. But devices without a handset, by definition, operate in a hands-free format.

- A voice message. An analogue of the answering machine function in phones, when the subscriber can leave a message if the owner of the intercom does not respond to the call. The function can be implemented in different ways, but in any case it is similar to the one with the usual expression: “Leave your message after the sound signal...”.

— Picture in picture. The ability to display a second image on the intercom screen, in addition to the main image. In this way, you can, for example, check the situation in the visibility range of a surveillance camera without interrupting communication with the visitor via the main video panel. The additional picture is small in size and is usually displayed in one of the corners of the screen.

- Motion Detector. A function that allows the intercom to detect movement in the visibility range of connected cameras and respond to it. The specific method of such a reaction may be different in different models: turning on recording, sending a notification to a user-specified device, sending a signal to an alarm output, etc.; These details should be clarified separately. In any case, the motion detector reduces the likelihood of missing significant events in the field of view of the cameras.

— Built-in memory. Built-in memory is found in video and IP intercoms (see “Device type”) and is usually intended for storing data from surveillance cameras. However, the volume of such memory is usually small, and it is usually used only for photographs (for example, to capture the faces of visitors); Video recording, if provided, is carried out on a memory card (see below). In any case, it would not hurt to clarify the operating features of the built-in memory separately.

- Frame. The ability to operate the intercom in digital photo frame mode - when photographs stored in the device’s memory (or stored on a memory card) are displayed on the screen (usually in slideshow mode). A mandatory feature of models with this function is a fairly large color screen - only on it photos will be normally visible; The intercoms themselves are usually video or IP models. The main purpose of the photo frame mode is aesthetic: showing beautiful pictures, the intercom plays the role of additional decor for the number.

Diagonal size of the intercom's own display.

In modern intercoms, there are displays ranging in size from 2 "to 10" — smaller screens are non-functional, larger ones are unreasonably bulky and expensive. At the same time, you can normally view the image on almost any display from this range — if you lean close enough to it.

With all this in mind, it makes sense to specifically look for a large screen (10 ") if you need to see it normally from a long distance (a metre or more), or if you do not want to strain your eyes once again, peering into a small image. Golden the middle is the 7" display.

The presence of touch buttons in the design of the intercom.

Unlike mechanical ones, such buttons do not need to be pressed in — they do not work by pressing, but by touch, which is somewhat more convenient. However, the main advantage of touch panels is still in a neat appearance and resistance to dirt. Such panels look modern and technologically advanced, they do not have protruding buttons that make it difficult to clean, and there are no gaps between the buttons and the panel itself, where dirt can accumulate. However they are somewhat more expensive and more difficult to manufacture than push-buttons; this is imperceptible to the average user, but is a disadvantage for manufacturers. That is why sensors, for all their advantages, have not supplanted traditional buttons.

A device for working with removable memory cards. Like built-in memory (see above), such media are used to record data from video panels and cameras; At the same time, for intercoms with card readers, the presence of a DVR is almost mandatory (see above), and it is the video that is saved to the memory card. This is more justified than using built-in memory for this purpose: removable media is cheaper per megabyte of volume and is better suited for large files, such as video recordings. In addition, we note that the card can be removed and installed in another device - for example, to copy footage to a computer or view it on a smartphone. The card may come included, but more often it must be purchased separately. It is worth considering the type and format of media supported by the card reader, as well as the maximum amount of memory with which it is compatible.

Power consumption of the intercom in the operating mode. Usually, this item indicates the value for situations where the device's functions are used to the fullest — in particular, when the display is on and the speakerphone is on (if any, see above). Note that the consumption in the operating mode rarely exceeds 20 W, so in most cases it is more of a reference, and not a practically significant parameter.