Comparison Dahua DHI-VTO6521H vs Dahua DHI-VTO6221E-P

This feature means that the device can be operated through a smartphone or tablet with a special app installed. Such apps are usually released for both of the most popular mobile OS of our time — Android and iOS; however, this point is worth double-checking separately. In any case, control from a mobile device can have quite extensive functionality; and interacting with the device through a gadget that you can always keep with you is definitely more convenient than having to approach the intercom or other stationary equipment every time.

Support for the SIP protocol enables the integration of devices into VoIP (Voice over IP) systems, allowing the use of internet connections for transmitting voice and video calls. SIP (Session Initiation Protocol) is a standard protocol for establishing, managing, and terminating communication sessions over the internet. In intercoms and door panels, SIP support enables video calls and communication with visitors through smartphones, tablets, or other SIP-compatible devices without the need for traditional phone lines. This also opens up opportunities for integrating the intercom system with other smart devices and security systems within a wider network, enhancing the device's flexibility and functionality.

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.

Type of multi-subscriber calling panel — a model designed for use in systems with a large number of subscribers (several dozen or even hundreds), for example, in residential apartment buildings. Such devices necessarily have digital keyboards, which differ in type.

— Button. Devices with traditional mechanical buttons. They are cheaper than touch-sensitive ones, and the buttons are easier to use by touch when dialing a number — they protrude more from the surface and are less prone to accidental activation. Another advantage of buttons is the ability to press them while wearing gloves (whereas touch sensors may not work); on the other hand, pressing requires a certain amount of effort.

— Touch-sensitive. Touch sensors give the panel an elegant and advanced appearance, and they are quite vandal-resistant — breaking a sensor, unlike a button, is almost impossible. Moreover, these keyboards are more reliable and durable because they have no moving parts that are prone to wear. Their main drawbacks include high cost and, in most cases, the inability to respond to a gloved hand, which can be inconvenient in cold weather.

Number of alarm inputs provided in the design of the call panel.

A special contact used to connect external security devices, such as an alarm or panic buttons. This input allows the call panel to integrate with a security system, so that in the event of unauthorized access or another emergency, an alarm signal is automatically activated (via a corresponding alarm output). For example, pressing the panic button on the call panel or attempting unauthorized door opening can send a notification to the internal panel or trigger an external siren, enhancing the security of the premises.

Number of alarm outputs provided in the design of the call panel.

This is a contact used to connect external devices, such as an alarm or security system, to trigger an alert or other security functions under certain conditions. This output can be used to send a signal to the security system, activate external sirens, or other alert devices in alarm situations, for example, during an attempted unauthorized access. The alarm output helps enhance security by ensuring timely responses to potential threats or incidents.

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 much the calling panel body. Protects sensitive internal components from dust and moisture. Standardly, it is designated by the letters IP with two numbers after them IP44, IP65, etc. The first digit means protection against penetration of solid objects and dust; its individual values correspond to the following levels of protection:

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

The second number characterizes protection against moisture, here the values can be as follows:


4 - protection against splashes from any direction;
5 - from jets from any direction;
6 - from sea waves or strong water jets;
7 - possibility of short-term immersion to a depth of up to 1 m (without the possibility of constant operation in submerged mode);

Of course, calling panels are not designed to be submerged under water - the latter option only characterizes 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 is not IP certified. At the same tim...e, the degree of uncertified 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 closure (at least dust resistance level 5).

The range of air temperatures in which the call panel maintains normal performance.

Outdoor panels installed outdoors and in unheated rooms are subject to the greatest temperature fluctuations, therefore, it is with this installation that this parameter should be paid special attention. At the same time, we note that even the most “heat-resistant” models must be protected from sunlight. If the conditions in the room are comfortable for people all year round, then they will be quite normal for the call panel, in such cases you can not look at the operating temperature at all.