Q.How does a CCTV digital video recorder work?
CCTV digital video recorder (or "DVR" for short) is essentially a computer that saves security video images to a hard drive. Most security cameras in use today capture an analog picture. The DVR converts the analog signal to digital and then compresses it.
Many cameras can be connected to one DVR. DVRs generally come with 4, 8, 16, or 32 camera inputs. The DVR will allow you to view all of these images at once or one at a time, and all of the video is saved to the hard drive. Additional switches, quads, or multiplexors are not required.
Q. Is all DVR's are the same?
Absolutely not! There are several factors that are critical to consider when purchasing a DVR, especially when comparing price. The most important factors to look at are the number of cameras supported, frames per second (fps), compression technology, hard drive space, network connection / remote viewing capability, motion detection, scheduling, and ability to save video and audio to a CD or flash drive. You should also look for easy and comprehensive search capabilities (check out our 'Smart Search' technology) and audio support. The setup and user interface should be intuitive and easy to operate.
Q. How many Frames Per Seconds will I see online?
There is no way to tell exactly how fast your video will come across the Internet. The speed depends on your connection to the Internet and the DVR's connection to the internet as well. The DVR's can use any sort of a Ethernet connection but are not compatable with a dial up modem connection.
Q. How do I see pictures from a remote site?
You can view the camera video over the internet using a modem which is slow but can display 1 or 2 frames every 5 seconds. Better is a DSL or cable modem connection which can generally display 1 frame per second. When viewing remotely, the refresh rate is restricted by the communications medium (your internet connection speed). When viewing or playing back locally, the display is dependent of the unit's frame rate . You will need a static ip address available to assign to the DVR
Q.What comes with the DVR?
Most of our DVRs come standard with an 250 gig hard drive (unless otherwise noted). They also include the software (for setup, local, and remote viewing), power cord, and documentation. PC-based machines also come with the mouse and keyboard. You just need to add the cameras, whatever cable you need, and a monitor. For embedded machines you can use a TV set or security monitor. For PC-based machines you need a standard computer monitor. Also, we have on-site technical support available at no additional cost.
Q. What happens when my hard disk is full?
Normally the system will begin to overwrite the recorded image files, oldest first. You can choose for recording to cascade from one drive to another i.e if the "C" drive is full, the system can begin to write on the "D" drive, if you have more than one hard drive.
Q. How big a hard drive do I need?
The amount of hard drive space is very important because it will limit how many days of recording you can store before the system has to start recording over the oldest video. Each DVR will have its storage capacity listed in the specifications. But this calculation is just a rough estimate as there are many factors that affect hard drive use. The most critical factor being the compression format used by the DVR (for more info on compression formats click here). But also the type of cameras that are connected to the DVR make a difference (specifically the chip size and resolution) and also the features that are selected on the DVR. If you use the scheduling or motion detection features or tune down the frame rate that will extend the storage capacity of the unit. Even the field of view will affect the storage capacity - the more complex the image, the more hard drive space it will take to capture the complexity.
Q. How far from the DVR can I place security cameras?
Using RG59 Coaxial Cable, each CCTV security camera can be placed up to 600 feet from the computer and up to 1,000 feet with RG6 Coax. Even longer distances (>2,000') can be achieved using Baluns and CAT5 cable
Q. What is 'Smart Search'?
Our PC-based DVRs come standard with smart search capability. This allows you to highlight one area of a captured image and look for changes just to that area. For example, if an item is stolen off of a counter. you can go to a moment in the video where the item is still on the counter, then highlight the area around the item and search automatically through the video for the moment in time when that particular area changes, that is precisely when the item is removed and then view that part of the video
Q. What is the difference between a PC-based DVR and an Embedded DVR?
PC-based digital video recorder is basically a personal computer that has been modified with hardware and software to work as a DVR. An embedded digital video recorder is a machine that has been manufactured specifically to work as a DVR. In embedded DVRs there is typically one circuit board with software burned into the chip.
There used to be significant differences in features between the PC-based and the embedded machines. But with recent advancements in the embedded DVR technologies the differences are becoming less. The advantage of an embedded digital video recorder is that they are extremely stable and reliable since they contain fewer parts. The software is often written in basic machine code or Linux code which tends to be more stable than Windows software. The advantages of the PC-based digital video recorders is that they are easier to interact with because you use the on-screen menus and a mouse. And you tend to have more features and options on the PC-based machines.
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