Hybrid mode (AHD+IP)
The number of cameras supported by the recorder when operating in hybrid mode — that is, when using traditional (AHD) and network IP cameras at the same time. For details about hybrid recorders, see "Type". And in this paragraph, the first number indicates the number of conventional cameras, the second — IP devices: for example, the entry "4 + 2" indicates that this model can simultaneously receive a signal from 4 conventional and 2 IP cameras.
Also note that some hybrid recorders allow different ratios between the number of cameras of different types (with the same total number of cameras). For example, a 12-channel model may have 6+6, 8+4, and 10+2 hybrid modes. In such cases, this paragraph takes into account the mode with the largest number of AHD cameras; for the model described in our example, “10+2” will be written in this paragraph.
It is also worth mentioning that when working only with IP cameras, the hybrid recorder can support a greater number of video channels than in hybrid mode — for example, in the “2 + 8” format model, the number of supported only network cameras can reach 16. This information is specified in "IP Only".
BNC video output
The number of BNC outputs provided in the design of the registrar.
BNC — connector with bayonet fixation for coaxial cable, used including for transmission of analogue video signal in professional equipment. Outputs with such connectors are designed to transmit a video signal to other components of the surveillance system — for example, monitors.
BNC outputs are found in all types of modern recorders (see above). At the same time, in DVR-type devices, their number, usually, corresponds to the number of BNC inputs, which makes it possible to switch the signal from each camera through its own output. In the NVR, most often only one connector is installed, which is intended for viewing recorded materials, and not images from cameras. The same option is also popular in HVR, although there are also models similar to DVR among them.
USB 2.0
The number of USB 2.0 ports provided in the design of the registrar.
USB is a universal interface for connecting various peripheral devices. In the case of registrars, we are most often talking about "flash drives" and other external media that can be used to copy files or update firmware. However, compatibility with other devices, such as manipulators (keyboards or mice), may also be provided.
Specifically, USB 2.0 allows you to transfer data at speeds up to 480 Mbps and provides a relatively low power supply. Because of this, this version is generally considered obsolete and is gradually being replaced by more advanced standards (primarily USB 3.2 gen1 - see the corresponding paragraph). However, USB 2.0 connectors are still very popular in registrars.
USB 3.2 gen1
The number of
USB 3.2 gen1 ports in the design of the registrar. This interface is used to connect various peripheral devices: USB drives for copying files or updating firmware, keyboards, mice, etc.
Specifically, USB 3.2 gen1 is the successor to USB 2.0. It supports higher data transfer (up to 4.8Gbps) and higher power supply.
Max. HDMI resolution
Maximum HDMI resolution.
The maximum image resolution that can be output via HDMI to the screen of the connected video equipment (monitor, TV, etc.). The HDMI output on the DVR allows you to stream Full HD, 2K or 4K images for high quality multi-screen images.
LAN speed
The maximum data transfer rate supported by the DVR's LAN ports.
Note that for simple tasks, a rather modest by modern standards speed of 100 Mbps is often enough. However, high bandwidth (
1 Gbps) not only simplifies the transfer of large amounts of data, but also helps to reduce lags and improve the overall quality of communication; and modern technologies make it possible to provide support for gigabit LAN even in fairly simple and inexpensive registrars.
Of course, in order to use all the features of the LAN, it is necessary that the devices connected to such ports also support the appropriate speeds.
Bandwidth
The maximum data stream in Mbit/s that the NVR is capable of processing when recording and displaying. The throughput parameter is specified as the maximum incoming/outgoing speed, or as the sum of incoming and outgoing streams (total throughput). It is calculated in such a way that the throughput exceeds the total flow of all IP cameras connected to the DVR, and another 25–30% is put in reserve for playing video or viewing it via network access.
Resolution (all channels)
The highest resolution in which the recorder can record video when a signal is received from all channels simultaneously. If cameras are not connected to some channels, the recording resolution may be higher (see “Maximum Resolution”).
Higher resolution has a positive effect on detail, but takes up more space and requires more computing power for processing, which accordingly affects the price of the registrar.
Frame rate
The highest frame rate in the recorded video that the recorder can support when recording from all available channels simultaneously. If not all channels are occupied by cameras, this figure may be higher.
The minimum required for comfortable viewing is 24 fps. And in the most modern video standards, the frame rate can be much higher — 50 – 60 fps. Higher values result in better quality and smoother video that allows you to clearly see fast movement; however, such video takes up more space and requires powerful hardware, which affects the price of recorders.
