Screen resolution
Resolution of the display installed in the intercom.
All other things being equal, a higher resolution provides a smoother and more detailed image, but it does affect the cost of the screen. In addition, all the benefits of high resolution are lost if the camera you are using does not support it. In general, this parameter is secondary: it is selected by the manufacturer based on the screen diagonal and the general functionality of the device, and for many screens it is not indicated at all - it is believed (and quite reasonably) that the resolution is in any case sufficient for its intended use. Therefore, there is no point in chasing
a Full HD screen ;
an HD display, or even
an SD one, will be enough.
Pluggable outdoor panels
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.
Display support
The number of additional monitors that can be connected to the intercom at the same time.
This function is relevant only for video-enabled models — video intercoms and IP intercoms (see “Device type”). In such models, the intercom itself is called a monitor — an indoor unit with a screen. This paragraph indicates how many additional indoor units can be connected to this model. The need for such a connection arises in cases where access to the security system must be provided from several points at once — for example, in a private house on several floors, where it would be inconvenient to run from floor to floor to the intercom. In this case,
intercoms with access to 3 monitors,
4 monitors or more are appropriate.
Note that the format of multiple monitors working together may be different, see "Connection Type" for more details.
Connected video cameras
The number of video cameras that can be simultaneously connected to the intercom. The mode of operation with these cameras can be different — a mosaic of several signals at once, switching between signals with each one displayed on the full screen, etc. However, anyway, to work with several video cameras, it is desirable that their corresponding number be directly claimed in the intercom — otherwise you will have to resort to installing additional equipment.
The simplest modern intercoms allow the connection
of 1 or
2 cameras, in more advanced ones this number can reach
4 or
more.
Alarm inputs
The number of
alarm inputs provided in the design of the intercom.
Such inputs allow the intercom to receive service signals from other elements of the security system — various sensors (motion, opening, temperature), cameras and video surveillance recorders, etc. This provides additional features for setting up the security system for certain events: for example, you can provide automatic activation of the video intercom camera when an opening sensor on an external wicket or gate is triggered. The specific functionality of alarm inputs for each model should be specified separately; however, anyway, such connectors allow you to increase automation and reduce dependence on the human factor. And the number of such inputs corresponds to the number of control components of the security system, which can be simultaneously connected to the intercom directly, without the use of additional equipment. Most often, it ranges from 3 to 8, and in some models it reaches one and a half dozen.
Alarm outputs
The number of
alarm outputs provided for in the design of the intercom.
Alarm connectors are used to exchange service signals between individual components of the security system, most often to automatically turn on a particular function. The presence of alarm outputs in the intercom allows you to transmit control signals from it to other security devices — locks, spotlights, surveillance cameras, a siren, etc. For example, you can configure the system so that when you press the call button, not only the video intercom camera, but also external surveillance cameras.
The specific functionality of alarm outputs for each model should be specified separately; however, anyway, such connectors allow you to increase automation and reduce dependence on the human factor. And the number of such outputs corresponds to the number of controlled components of the security system, which can be simultaneously connected to the intercom directly, without the use of additional equipment. However, for a number of reasons, this number rarely exceeds 1.
PoE power
Support for POE (Power Over Ethernet) is found only in models with a 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.
Consumption (during operation)
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.
Operating temperature
The temperature range at which the intercom is able to work normally.
If the device is installed in a residential area or office, you can not pay much attention to this parameter: the temperature in such an environment rarely goes beyond +18 ... +25 °C, such values are normally tolerated by any intercom. But if the device needs to be placed in a "non-standard" microclimate — for example, an unheated warehouse, where conditions do not differ much from outdoor ones, or a production workshop with a high temperature — you should make sure that the chosen model can normally endure such conditions.
Separately, we note that even the most “heat-resistant” intercom cannot be exposed to prolonged exposure to sunlight.
