Comparison Commax CDV-70H2 vs Commax CDV-70N2

— With a tube. Devices with tubes like those used in telephones. Audibility in the handset is better than in the speakerphone, and to answer a call, usually, it is enough just to pick up the handset from the device — this method is intuitive even for those who are far from modern technology. And the moment that only the user hears the guest, in some situations, it also turns out to be useful — for example, so as not to disturb others. On the other hand, these advantages are not so often key, while the handset makes the design more cumbersome, and when talking, you need to take one hand (the latter, however, can be compensated by the presence of a speakerphone, see "Additionally"). Therefore, this version is much less common than the tubeless one (see below)

— No tube. Intercoms that do not have a handset — communication takes place through a speakerphone and a microphone in the case. Such models are more compact and look more neat than devices with a handset, when talking, the hands remain free, and everyone who is nearby can talk with the guest; sometimes such a conversation is preferable to talking through the phone. This embodiment has practically no drawbacks, and therefore is considered the most advanced today and is used in most intercoms.

— Portable. Intercoms, made in the form of autonomous devices that can be constantly carried with you. Such...models are very convenient if it is difficult for the user to approach the stationary intercom every time — for example, when it comes to a house with 2-3 floors, or if the intercom is used by an elderly person. On the other hand, portable tubes are more expensive than stationary ones and require care in use: you need to recharge the battery in time so as not to be left without an intercom at all. And since the real need for portable devices does not arise so often, and they cost much more than stationary ones, the popularity of this option is not high. Note that radio intercoms (see "Device type") are considered only those portable models that are connected to the call panel directly, without a wired base; at the same time, in fact, it is the variant with the base that is most often used.

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.

Type of connection with additional monitors (see "Number of monitors") supported by the intercom

— Consistent. With this type of connection, all external security devices — calling panels, cameras, locks, etc. — are connected only to the main intercom. Additional monitors used in the system are connected in a "chain", one after another, and work only through the main unit; you cannot connect security equipment directly to an additional monitor. With this format of operation, the number of security devices is limited by the capabilities of the main intercom, but they can be accessed from any system monitor.

— Parallel. Like serial, this option assumes the presence of a main intercom and additional monitors. The key difference lies in the fact that you can connect your own video cameras to each controlled monitor, which will be controlled only from this monitor. This option is convenient when organizing security systems with several separate video surveillance zones: for example, the main monitor can be installed at the main entrance, and the additional monitor at the service entrance, and each of them will only work with the camera above the corresponding door.

The total number of ports for wired connection of various equipment provided in the intercom; in fact — the maximum number of wired devices that can be simultaneously connected to the intercom.

Keep in mind that this number may be less than the total amount of supported devices. This is especially true in models with the possibility of using additional monitors (see "Connected monitors"): such devices are often connected in series, "chained" and occupy only 1 port. Thus, for example, an intercom for 2 calling panels and 3 monitors can have only 3 connectors — one for calling panels and one for monitors. Note also that the LAN port in IP intercoms (see "Device type") is also taken into account in this calculation.

The number of outdoor panels that can be connected to the intercom at the same time.

The call panel is an external panel through which the guest sends a call to the owner of the intercom and communicates with him. Such a panel should be at each door "covered" by the intercom. This means that the number of supported outdoor panels corresponds to the maximum number of doors with which this model can be used. The simplest option is 1 calling panel, but in fact this is often not enough. Therefore, models that can block 2 doors at once are more popular — for example, the main and service entrances to the office. And in the most advanced intercoms, it may be possible to connect 4 calling panels at once, or even more.

The longest continuous conversation that the intercom provides. Technically, this duration can be unlimited, but in fact, limits can also be set — usually from 1 to 4 minutes. This is primarily due to the fact that in systems with several call panels, a conversation through one of them may interfere with the work of the others. Limitations on the duration allow you to exclude long conversations and possible overlays, and the available time is usually enough to clarify all the necessary questions during one conversation. Also, this feature is useful in case you forget to turn off the connection (hang up) at the end of the conversation.

The longest video duration that the intercom can record for later viewing. This can be either a conversation recording or a video recording of a visitor when working in the “Away” mode. In both cases, a long duration is not required, therefore, in most cases, this parameter is several tens of seconds.

— 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.

The amount of energy consumed by the intercom in standby mode. In this mode, the device is energized and is in a state of readiness to receive a call; no functions are used, and the readiness itself does not require a lot of energy. Therefore, the value of this parameter, usually, is rather low, and you should pay attention to it only if you fundamentally strive for maximum efficiency of the installed equipment.