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.
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.
Alarm input
The number of alarm inputs provided in the design of the registrar.
Alarm inputs allow the recorder to respond to various events and signals from other elements of the security system. For example, a door opening sensor can be connected to such an input, and upon a signal from it, the registrar will turn on the camera above this door. This ensures the automation of the security system and makes it less dependent on the human factor.
Alarm output
The number of alarm outputs provided in the design of the registrar.
Alarm outputs are used to transmit signals from the recorder to other elements of the security system — an alarm siren, electronic locks, spotlights, etc. Thus, the system can automatically respond to events recorded by the registrar — for example, block the doors when moving in the frame.
RS-485
A physical interface for managing and monitoring various aspects of a video surveillance system. As a rule, the
RS-485 connector is used in recorders to control PTZ cameras, connect keyboards, matrix switchers and other similar equipment.
RS-232
The presence of an
RS-232 service interface in the recorder (also known as a COM port). Through such a connector, it is usually possible to remotely control the device’s operating parameters from a computer or specialized equipment using appropriate software. Also, the RS-232 port can be used to update the recorder firmware.
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.
