Camera connection
Possibilities for connecting cameras available in the registrar.
For analogue DVRs and digital NVRs (see "Type") in this case, everything is simple: the number of video channels corresponds to the largest number of incoming video signals that can be connected to the device. Such a signal can come both from a camera and from an intermediate device — for example, a quad that combines a picture from 4 cameras. But in hybrid HVRs, the meaning of this paragraph is more specific. For these recorders, this specifies the maximum number of inputs that the device can handle in AHD only mode (i.e., analogue cameras only, no IP cameras). Data on hybrid mode (AHD+IP), as well as for using only IP cameras, are given separately for such recorders (see below).
Numerous channels (
32 channels,
64 channels and even
128 channels) allows you to create an extensive video surveillance system based on the registrar without using additional equipment (for example, the same quads). On the other hand, this characteristic significantly affects the price, and for living conditions,
registrars for 4,
8 or
16 cameras are quite enough.
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.
PoE outputs
Number of LAN ports (RJ45) with PoE support provided in the recorder design.
These connectors are intended for connecting IP cameras. And PoE technology makes it possible to supply power to such a camera directly via the connection cable, thus dispensing with a separate connection to an outlet and without batteries/accumulators. Of course, to use this technology, the camera connected to a similar port must also use it. Most often, the number of channels corresponds to the number of PoE outputs (this can be
4 outputs,
8 or even
16 ports). But there are always exceptions.
Total PoE power
The total power that the NVR is capable of delivering to all PoE outputs.
See above for details on such exits; here we only recall that the general idea of PoE is to supply power over the same Ethernet cable that transmits data. The total power is given for models in which there are more than one such connectors; it allows you to estimate the total power consumption of all PoE devices that can be connected to the NVR at the same time.
There are two important things to keep in mind when choosing a specific value. First, when multiple ports operate, the energy is usually shared equally among them; at the same time, the total power of the registrar does not always correspond to the sum of the maximum powers of all PoE outputs. For example, a model with 8 ports of 30 W each may have a total figure of not 240 W (8 * 30 W), but only 100 W. In fact, this discrepancy means that with the simultaneous use of all connectors, each of them will be able to deliver not 30 W, but a maximum of 100/8 = 12.5 W. The second point is that the total power consumption of the load should ideally be no higher than 75% of the claimed total PoE power — this provides an additional guarantee in case of malfunctions.
