#Pelco
4-channel DVRs at small distributed sites.
The usual classification of sites (large, medium and small) implies dividing recorder models by the number of channels.
Thus, for large objects, devices with 16 channels and more are used, the needs of medium-sized objects are met by equipment with 8-10 input channels; small objects have a small number of cameras, so recorders with a number of channels from 4 to 6 are installed on them.
It is necessary to separately highlight the segments where single-channel devices are used.
On the other hand, there are a number of specific video surveillance objects that have a large number of cameras in total, but these cameras are installed locally in small groups.
Such objects include small shops, bank branches, pharmacies, gas stations, ATMs, etc.
As a rule, the topology of the video surveillance system at such objects is similar: the cameras installed for video surveillance of the object are “monitored” from a single center.
I will immediately stipulate that here two approaches to building a video recording system are possible.
The first is that cameras located in local locations transmit images to a single monitoring center, which is recorded there on a server or on specially designated network recorders.
It is clear that it is impossible to transmit a signal from analog cameras over such a distance, so we are talking about IP cameras and IP systems.
But if there are a large number of remote objects (for example, a branch of a territorial bank of Sberbank of Russia may have hundreds of additional offices scattered throughout the entire region), administering such a network can be a very expensive and labor-intensive task.
In addition, one cannot ignore the quality of most Russian communication channels. As a rule, there can be no talk of transmitting «live» video.
Therefore, the second method is currently more trusted: organizing a local center for recording and storing information at each site using a digital recorder.
DVR can also transmit information to the central office via existing networks continuously, if communication channels allow it, or upon request, at strictly designated time intervals, as well as in the event of an alarm situation.
Here it should be noted that for a number of objects, such as an ATM, the presence of «live» video is not necessary. This function is necessary, so to speak, for visual identification of the system's operability.
Another advantage of this approach is that the archive is guaranteed to be safe, and the quality of the local recording will be much higher, which means that the recording made by the DVR can help law enforcement agencies in the event of illegal actions.
In fairness, it should be noted that when we call a recording device a DVR, we mean the use of both a PC-based and a Stand alone DVR.
The decision should be made by the user, based on the functional requirements and the required level of reliability of the system.
Stand alone DVR is a complete autonomous device that performs a certain set of functions and is focused on recording and visualizing video images.
Stand alone DVRs use, and this is one of their main differences from PC-based systems, specialized operating systems: Linux or Real Time Operation Systems (RTOS).
Built-in functions for monitoring the status of the recorder allow increasing the reliability of the autonomously installed recorder.
After all, if there is no operator at the facility (for example, in the case of installing a DVR in an ATM), there is no one to quickly come and fix the malfunction, reboot, if necessary, the recorder, etc.
But what if you need to go to the other end of the city or, worse, the region?
Here, reliability is the determining factor.
I would like to clarify the number of channels used in the video surveillance system of small distributed objects.
There is no general rule here, although similar objects are characterized by uniform rules for constructing a system.
In the case of stores, or more precisely, chain stores, there is a fairly clear gradation of how many cameras should be installed at each object.
From experience, 4-channel recorders are used in small stores where there is only one cash register.
Larger objects require the installation of more cameras.
When organizing video surveillance in ATMs, until recently it was necessary to explain why it is necessary to install at least 2 cameras in an ATM: in addition to the portrait one, it is necessary to have a camera installed in the cash withdrawal area.
Now some banks are ready to install up to 5 cameras for 1 ATM: portrait, cash withdrawal area, cash acceptance area, camera inside the ATM to record the actions of collectors and a camera recording the actions around the ATM.
The bloody statistics of attacks on bank branches also forces us to reconsider approaches to organizing video surveillance, as banks come to the understanding that 4 cameras are not enough everywhere, because it is necessary to record the perimeter around the branch, events occurring inside, the faces of everyone entering, etc.
I would like to say something about chain gas stations.
I think my colleagues can give examples of installations of 4-channel recorders at such facilities.
But I, for example, am sure that even for a small gas station, four cameras are clearly not enough, — after all, the cameras need to see all the cars entering the gas station, provide control over the cash register (cash registers), the store (they are now at almost every gas station).
However, practice shows that for small distributed objects, 4-channel recorders are used in most cases.
On the other hand, it is necessary to provide for the possibility of expanding the system with recorders with a large number of channels, while there must be full compatibility of the equipment so that monitoring is carried out by a single software.
Let's try to formulate the basic requirements for DVR for distributed objects:
1. Recording information from video cameras for further processing.
2. Possibility of receiving both live and previously recorded images over the network.
3. Transmission over the network and saving of video segments in the monitoring center. 4. Remote configuration of the recorder.
5. Adaptation of the recorder to network conditions (regulation of bandwidth).
6. Receiving alarm notifications over the network.
7. Special features.
8. Ensuring the reliability of the equipment, in accordance with possible risks.
Let's dwell on some parameters in a little more detail.
Such obvious functions as recording, transmitting «live» video and viewing previously recorded video, as well as saving segments (downloading) do not require additional comments.
Remote configuration of recorders significantly reduces service costs, since it allows this operation to be performed without going to the place where the device is installed.
One of the frequently asked questions in Russia: what should be the minimum bandwidth for recorders to work correctly.
When our Japanese engineer heard this question for the first time, he was very surprised.
And after realizing that the questioner was interested not in the maximum, but in the minimum bandwidth, he answered that for our equipment this value does not matter, the main thing is that the channel is stable.
In any case, bandwidth limitation allows for more precise network configuration so that the recorder does not affect the work of other departments.
Receiving alarm notifications is the right way to work with a large number of installed recorders.
For example, an operator cannot track in real time whether the card owner is actually withdrawing money from the card.
But it must react to an alarming situation (loss of video information, stop of recording, failure of the recorder) instantly.
Special features are not necessary, but provide the user with additional convenience when working with recorders.
For example, automatic time synchronization is necessary to «link» the DVR time to the time of the central monitoring computer.
Recording transaction information allows you to match the card number with the photo of the person performing the transaction.
When video surveillance of cash transactions, the presence of captions allows you to investigate cases of operator fraud.
The presence of mirroring — creating a backup copy of information — allows you to increase the reliability of the equipment used.
There are various copying options, such as archiving a specified interval — to do this, you need to set the start and end points, and the video recorder will determine the file size and, accordingly, the required volume of the storage medium where the copying will be made.
Copying can also be done from the start point until the space on the external storage medium runs out.
Such copying is, in fact, active mirroring, since the archive volume can be many times larger than the volume of information stored on the internal hard drives.
In such models, any USB devices can be used as storage devices for archival information, but most often, standard expansion units from the manufacturer or network storage devices are used.
Now about the last parameter on the list (but not in importance) of equipment reliability, the degree of which should correspond to the risks of losses at a given facility. Agree, a small grocery store in terms of the cost of possible losses is very different from a jewelry store or a bank branch.
It is sometimes very difficult for an installer, and even more so for a customer, to decide which equipment to choose for their task, since all the functions necessary for DVR are present in the technical specifications of all manufacturers.
Therefore, the main criterion when choosing is often the price of the equipment, according to the principle of «not the most expensive and not the cheapest».
Let me note once again that it is important to proceed from the characteristics of the object and the specific tasks set by the customer.
For example, according to the reliability/failure theory, the following periods of operation of any device made on the basis of electronic components can be distinguished:
— the period of «childhood illnesses»;
— the period of stable operation;
— the aging period.
The first period is characterized by a fairly high failure probability.
An important difference between the equipment produced by leading companies — sometimes called «branded» in everyday life — is that they «treat» «childhood diseases» themselves.
Very strict additional testing is carried out, and the consumer receives the equipment already at the stage of «stable» operation.
The second important parameter is the probability of equipment failure during the period of «stable» operation. Branded equipment usually has a very low indicator: within 1%. And, as a rule, it is distinguished by a sufficiently long period of failure-free operation.
Meanwhile, the duration of this period is a very significant criterion for many objects. There is no such indicator in the characteristics declared by the manufacturer, but practical experience forms a list of brands for which this indicator is quite high.
And then the choice is made from this list.
In conclusion, I would like to note that when choosing equipment, it is necessary to check with the manufacturer about the availability of support for the equipment line and the compatibility of new models with previous ones. When building relationships in the long term, it is necessary to more carefully assess the supplier and the equipment used, so as not to be left with nothing in a few years.
Digital video recorder SHR-5040P, SHR-5042P (Samsung)
It has 4 channels for recording video signals from video cameras in CIF format at a speed of 100 images per second and 4 channels for recording audio.
The video recorder uses the MPEG-4 image compression method and the ADPCM (adaptive differential pulse-code modulation) audio method to record data to the hard drive or simultaneously read it from the hard drive.
In addition, the video recorder uses a dual codec, which provides simultaneous recording and transmission of video/audio signal via the network in real time and allows you to control the image and sound remotely using a personal computer.
The presence of a USB 2.0 port allows you to save data to an external hard drive or USB flash memory. The SHR-5042P model has a built-in CD-RW drive.
Network 4-channel video recorder STR-0484/MPEG-4 (Smartec)
This video recorder uses the MPEG-4 compression format and allows you to record video on each channel with the selected resolution and frame rate, as well as transmit it over an IP network.
The operator can assign a resolution of 2CIF (720 x 288 pixels) or CIF (352 x 288 pixels) and record/play video at a speed of 100 fps or Full D1 resolution (720 x 576 pixels) at a frequency of 50 fps.
Video streams are recorded on a built-in 250 GB SATA drive, which can be replaced with a more capacious one or a second SATA drive can be installed in a free slot, bringing the total disk space to 2 TB.
At the same time, the video recorder supports all the necessary functionality for managing recording, searching and playing video.
For local viewing, you can connect a CRT, LCD or computer monitor to the STR-0484, as well as a Spot monitor.
The STR-0484 features 4 audio inputs and output, DVD/RW, RJ-45 and 3 USB ports, motion detection, 4 alarm inputs/outputs and an RS-485 interface for controlling PTZ cameras using 9 different telemetry protocols, including the most common Pelco P/D.
The STR-0484 and cameras can be controlled from the front panel, from the IR remote control (included), from the Smartec STT-CN3R1 keyboard, or over the network via the RMS software interfaces that come with the device.
Video recorder NDR-C400EZ (Infinity)
The new MPEG-4 video recorder Infinity NDR-C400EZ is a professional entry-level system for recording four video channels at a maximum speed of up to 100 frames per second.
The information is recorded on a hard drive with the ability to subsequently archive it on external devices (USB 2.0 port).
A convenient Russified menu allows you to easily and quickly control the recorder directly at the installation site or over the network (Ethernet 10/100 Mbit, software included).
For remote control via the network, the Infinity RAS plus software is used, which also works with the older NDR-S, NDR-X and NDR-DLX series recorders, so the NDR-C400EZ can be used not only as a stand-alone recording device, but also as an element of a large distributed video surveillance system.
The advantages of this system also include its relatively low cost, which, combined with rich functionality, makes the NDR-C400EZ an excellent solution when choosing equipment for a surveillance system.
BestDVR-402A-S (BestDVR) Video Recorder
The main advantage that makes the BestDVR-402A-S an excellent choice for working over the network and the Internet is the most effective compression algorithm to date, H.264, which allows access to live video, archive and settings even through a “thin” (from 32 kb) communication channel.
By the way, you can access the recorder both through the client software and through Internet Explorer.
The recorder has all the necessary functionality: 4 video, 4 synchronous audio, individual choice of resolution and recording speed, motion detector and abandoned object detector, schedule, password-protected access, BNC and VGA video outputs, the ability to read a removable disk on a PC, a USB port for archiving.
The maximum disk space of 4 TB (4 SATA disks of 1 TB) will allow you to keep video recording for many months.
Video recorder V1netServer540R (V1net)
The 4-channel network video server is designed to organize video surveillance systems at small sites.
With the help of free software (NVR-PRO) and an existing local or global network, these recorders are combined into a single distributed system that includes up to 64 video surveillance channels.
Three independent zones allow you to fine-tune the motion detector for each channel separately.
Up to 4 alarm sensors and up to 2 alarm devices can be connected to each video server. V1netServer540R is equipped with an RS-485 port for connecting PTZ cameras controlled by Pelco protocols and others.
Four audio inputs and one audio output allow you to organize a conference call in real time.
V1netServer540R records information on a built-in hard drive (up to 750 GB) in MPEG-4 format with a maximum resolution of 720 x 576 and a recording speed of 25 fps per channel.
This video server has a compact size, which simplifies hidden installation.
Digital duplex video recorder EDR-410H/M (EverFocus Electronics Corp)
It is used in stationary (modification H) and non-stationary (modification M) conditions.
Video standard — NTSC/PAL. Has a duplex mode of operation.
Total recording speed: 25 IPS at 720 x 576; 50 IPS at 720 x 288; 100 IPS at 360 x 288.
Recording can be done in three modes: continuous, timer, alarm.
EDR-410H/M provides real-time monitoring, work with 4 color and b/w cameras.
MPEG-4 compression. Included HDD (500 GB) — with «hot swap». USB 2.0 and Compact Flash slot for backup. Event logging is provided.
There is a motion detector with flexible settings and sensitivity changes for each camera, two audio channels.
The system login is protected by a multi-level password. Support for HTTP, TCP/IP, SMPT protocols. There are programmable alarm inputs and outputs, a user interface in Russian.
The video recorder automatically restores functionality after a power failure.
Digital recorder DX-TL304E (Mitsubishi Electric)
The recorder allows you to record from 4 cameras connected to it at a speed of up to 100 fields per second, using the MPEG4 compression format.
The image entering the camera lens is displayed on the operator's screen of the video surveillance system at a rate of 200 fields per second when displaying 4 cameras on the monitor, and thanks to the functions of the triplex multiplexer, it is possible to simultaneously view a previously recorded image on the monitor screen without stopping the current video recording.
The total archive size can be easily increased by using external DX-ZD6 expansion units connected via a serial port.
Thus, the total disk space can be 9 TB.
Information from the hard drives installed in the DX-ZD6 expansion unit can be viewed on a regular computer after connecting them via USB.
DX-TL304 supports caption recording, which allows the recorder to be used in video surveillance systems for ATMs and cash transactions.
With the help of DX-PC200 software, the video recorder is connected to a single monitoring network consisting of any DVRs produced by Mitsubishi Electric.