The frame rate is number of images that are being displayed or recorded over a specific period of time. Typically frames per second or "fps" is the specification most often used. Remember frame rate record and frame rate display are two different items. Just because it displays in real-time doesn't necessarily mean its capable of recording in real-time.

A (DVR) Digital Video Recorder is in simplistic form, a PC which acts like a VCR in that it has the ability to record and playback video images. The DVR takes the feed from a camera and records it into a digital format on a storage device which is most commonly the hard drive.

Real time images are those images that are being transmitted as they happen, not to be confused with real motion. Unfortunately, the words real time and real motion are used synonymously within the industry. Just because something is real-time does not mean it is real motion.

Industry standards typically speak of 25/30 images per second as real motion video.

What the manufacturers often fail to tell you is that a 25fps video capture board is the "maximum" frame rate that the video will display. The maximum frame rate is what can be achieved prior to the introduction of other important criteria such as hardware and software processing and video compression and network connection speeds; either of which attributes to the degradation of the capture rate. A 25 fps capture board may lose as much as 20% of its capacity through software compression.

The vast majority of DVR manufacturers describe a system in terms of "shared frame rate" which is somewhat misleading. What that means is a 25fps system is 25 frames per second over the entire number of cameras being displayed. Therefore, a 16 camera system sharing 25 frames may yield less than 2 images per second.

DVR's are low power consumption devices. Remember, they are in essence a PC. It is recommended that you attach a battery back up to the DVR to protect the hardware against power spikes, reductions or outages.

Your existing cameras will work and simply plug into the back of the DVR which replaces the VCR. If your cameras are not so current you may want to investigate some of the newer cameras which are higher in resolution and may have more features. Typically, higher resolution cameras mean higher quality images.

The simple answer is yes.

Absolutely. Just as important as the hardware is the software that operates the hardware. The software that runs the principal functions of the DVR is driven by a database. The architecture and design of the database are crucial for system stability and speed of which it processes the data. Quite often poor database structure will slow down even the best hardware and in many cases, cause system crashes.