Comparison Dahua DH-VTO2111D-WP vs Dahua DH-VTO2000A

Call panel installation method.

— Mounted. Installation by hanging from fixtures placed on a wall, door frame, or other suitable location. This method is quite simple, besides, it allows you to relatively easily change the location of the device. On the other hand, it is less reliable than embedding, and it is easier for hooligans or thieves to rip such a panel from its attachment point.

— Embedded. Installation in a niche in a wall or other surface — in such a way that only the front side of the device is outside. and any movement of the device is also fraught with serious difficulties. Nevertheless, it also has advantages: it is almost impossible to remove the call panel from a niche without a special tool, and even with tools, this task takes time and effort.

— Mounted / built-in. This category includes outdoor panels that allow both of the installation options described above. Thus, the user can independently choose a method, depending on what is more important in this case: ease of installation or its reliability.

A method for connecting the calling panel to an intercom or other similar device.

All modern connection types can be divided into three main categories: wired analog(2, 3 or 4 wires), wired digital(network - LAN) and wireless(Wi-Fi). Moreover, the last two formats can be combined in one device. Here is a more detailed description of each of these options:

— 2-wire. The simplest type of wired analog connection; used in select low-cost audio panels (see "Type").

— 3-wire. A very rare option: in simple analog devices, manufacturers often provide 2 wires, and in advanced ones - 4.

— 4-wire. The most functional and, as a result, the most popular type of analog wired connection. Suitable even for high-end video panels, although in fact it is found in all categories of devices - from budget to high-end.

— RJ-45. Connection via an RJ-45 connector via an Ethernet network cable (“twisted pair”). This option is convenient because the calling panel can be connected to a local computer network, which provides several advantages. Firstly, the ability to access the panel can be configured on any computer or gadget within the network. Secondly, many similar models can work without intercoms and other special equipment - through an application on a computer/gadget. Thirdly, laying a network cable from the panel to the router.../switch is often simpler than organizing an analog connection (for example, 4 wires - see above). Fourthly, the number of panels and other special equipment within the local area can be almost any - it is quite possible to combine, for example, all the calling panels of an apartment building or a large office center into one network. And if you wish, you can even set up access to the calling panel via the Internet, which will make it possible to communicate with visitors and control access to the premises, even when you are not on site.

- Wi-Fi. Connection via Wi-Fi wireless standard. This option provides almost all the same capabilities as the RJ-45 described above, but has certain differences. The most noticeable of them is the absence of a wire, which greatly simplifies installation and connection. At the same time, even relatively limited Wi-Fi devices have the power to operate reliably at a distance of a couple of tens of meters or through 1 - 2 medium-thick walls. The second nuance is the possibility of direct communication with a smartphone, tablet, etc., without using computer networks; This possibility should be clarified separately, but it is in this format, for example, that video calls work (see “Type”).

— RJ-45 / Wi-Fi. Supports the two connection methods described above at once. Such panels turn out to be as universal as possible, however, in practice, the ability to freely choose between LAN and Wi-Fi is extremely rarely required, and it significantly affects the cost. Therefore, this option was not particularly widespread.

— Motion detection. A sensor that allows the calling panel with a camera to respond to movement in the camera’s field of view. The specific reaction method may be different, depending on the model and settings of the entire system: turning on recording or broadcasting to an external device, sending a notification to the customer, sending a signal to the alarm output (see below), etc.

- Mobile app. This feature means that you can work with the calling panel 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; however, 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 the panel through a gadget that you can always keep with you is definitely more convenient than every time going to the intercom or other stationary equipment.

— Face recognition. The facial recognition function is one of the types of biometric access systems. It is based on a digital camera, often complemented by a built-in backlight for identifying faces in the dark. Initially, such devices were not very accurate: they could be confused by changes in facial hair o...r makeup, the appearance or disappearance of glasses, and some models could be deceived using photography. With rare exceptions, facial recognition today uses advanced algorithms and high-end cameras with 3D scanners that read a three-dimensional model of the face. The device stores the customer library in its memory. The function is found in flagship calling panels.

— SIP protocol. The device supports the SIP protocol. This is a standard originally created for Internet telephony - the transmission of information (audio, video, special data) over telephone networks in digital format using the IP protocol (the same one on which the Internet is built). Internet telephony is quite popular nowadays, especially in business: it allows you to establish effective interaction between individual departments of a company, even tech located in different countries. Accordingly, if the building already uses equipment for Internet telephony, then SIP support can significantly facilitate the integration of the calling panel into the overall security system.

— Reading contactless keys. The presence in the design of the intercom calling panel of a module for reading data from contactless keys. They can be in the form of smart cards, key fobs or other devices that contain a microchip with a unique identifier. When the customer brings the key to the reader, the system identifies it, checks it against the database and allows access if there is a match. Note that the intercom calling panel can record not only the response time, but also the identifiers themselves - this provides advanced capabilities for access control and visitor registration.

— Alarm input/output. As a rule, calling panels with this function are equipped with both inputs and outputs; the number of both may be more than one. In general, these connectors are used to transmit control signals between different ones within a security system; they allow you to build a very advanced system and provide additional capabilities for managing its functions. At the same time, we note that the alarm input or output is not necessarily responsible for triggering the alarm - it all depends on the specific settings. For example, a signal from such an input can serve as a command to turn on the “night” IR illumination or start recording video from surveillance cameras.

— Display. Its own screen, installed directly on the calling panel, allows you to display various additional information useful for the visitor. The specific functionality of such a screen can be different - from a simple indicator that can show only numbers (for example, the number of a called apartment or office) to a full-color display suitable for two-way video communication. However, in any case, this feature increases the convenience and clarity of using the calling panel.

— Night shooting (IR illumination). The presence of an infrared illumination function in the camera video panel (see “Type”), which allows you to obtain a visible image in the dark and even in complete darkness. IR illumination is not visible to the human eye, but is well perceived by the sensors of modern digital cameras. True, the image in this mode can only be black and white, but in most cases this is not any significant drawback.

— LED backlight. The camera video panel (see “Type”) has LED backlighting. Like the infrared illumination described above, this backlight is designed to work in the dark; however, it provides light that is visible to the human eye. The latter, on the one hand, allows the camera to produce a relatively natural color image, on the other hand, it can create inconvenience for the guest due to the bright light in the eyes.

— Illuminated buttons. The design of the calling panel includes backlit buttons. The function allows you to see the keyboard normally even in low light conditions - in the evening, at night, in cloudy weather, when placing the panel in a dark place, etc. Note that the backlight usually covers other significant elements of the panel - for example, the location of the sensor for a smart card or key.

Diagonal size of the surveillance camera matrix. This parameter is traditionally indicated in inches and fractions of an inch.

With the same type (see above) and the number of megapixels (see below), larger sensors are considered more advanced. This is due to the fact that a large sensor size means a larger area of each individual pixel — and this, in turn, increases the amount of light falling on each pixel, has a positive effect on light sensitivity and reduces noise. Large sensors are especially important for working in low light conditions, including with IR illumination (see "Design and capabilities"). However, for calling panels, matrices are mainly limited to 1/4" and 1/3" sizes. Other options are much less common.

The number of megapixels in the camera sensor, in other words, its resolution. A megapixel is one million light-sensitive dots (pixels) that make up an image; the resolution of modern matrices is very high, so it is more convenient to use just this method of designation. However, for call panels, the values are 1 MP, 1.3 MP and 2 MP. More advanced options are extremely rare.

The higher the resolution of the matrix, the higher the video resolution can be (see below), the more detailed the image can be provided by the door panel camera. At the same time, note that as the number of megapixels increases (without changing the size of the matrix), the size of each individual pixel decreases, which increases the likelihood of noise and deterioration in the overall image quality. Therefore, high resolution in itself is not necessarily a sign of high quality — a lot depends on other things, for example, on the size of the matrix (see above).

Horizontal size of the video panel covered by the camera (see "Type"); this size is most conveniently indicated by the angle between the lines connecting the camera lens with the left and right edges of the scene being viewed.

Theoretically, the wider the viewing angle, the more space the camera is able to cover and the less likely it is that some details will remain out of the frame. At the same time, taking into account the specifics of the use of outdoor panels, it is usually not necessary to equip them with wide-angle cameras; moreover, such optics would be inconvenient due to distortion and reduction effect. Therefore, most models have horizontal viewing angles in the range of 60 – 80 ° — this is quite enough for the intended use.

The vertical size of the video panel covered by the camera (see "Type"), in other words, the angle between two lines connecting the lens with the top and bottom edges of the scene being viewed. The value of the viewing angles is described in detail above in paragraph "Viewing angles horizontally"; we only note that they are usually smaller vertically than horizontally, and in many models this parameter is not indicated at all because of its secondary importance.

Call panel support POE (Power Over Ethernet). This feature is only found on models with LAN connection. As the name suggests, it allows power to be supplied through the same network cable that connects the device to an intercom or other device. This is much more convenient than laying a separate wire for power or fiddling with autonomous power sources.

This protection describes how well the case protects sensitive internal components from dust and moisture. By default, it is denoted by the letters IP followed by two numbers — IP44, IP54, IP55, IP65, IP66, etc. The first digit means protection against the ingress of solid objects and dust, and the following levels of protection correspond to its individual values:

4 — protection against objects with a diameter of more than 1 mm
5 — dustproof (full protection against contact; dust can penetrate inside, but does not affect the operation of the device)
6 — dust tight (enclosure with full protection against dust and contact). br> Smaller values do not occur and there is no point in specifying them.

The second digit characterizes the protection against moisture, here the values \u200b\u200bcan be as follows:

1 — protection against vertically falling drops of water;
2 — from water drops with a deviation of up to 15 ° from the vertical axis of the device;
3 — from water drops with a deviation of up to 60 ° from the vertical axis of the device (the minimum level that allows the device to be operated in the rain);
4 — from splashes from any direction;
5 — from jets from any direction;
6 — from sea waves or strong water jets;<...br> 7 — the possibility of short-term immersion to a depth of 1 m (without the possibility of continuous operation in immersed mode);
8 — the possibility of long-term immersion to a depth of more than 1 m (with the possibility of continuous operation in immersed mode).

Of course, outdoor panels are not designed for immersion under water — the last two options only characterize a high degree of moisture resistance.

In some models, one of the numbers may be replaced by the letter X — for example, IPX7. This does not mean that there is no protection, but that the corresponding parameter was not certified according to the IP standard. At the same time, the degree of non-certified protection can be quite high — for example, the example above corresponds to the possibility of complete immersion under water, which requires a high degree of closeness (minimum dust resistance level 5).