The use of digital video recorders (DVRs) instead of VCRs has greatly improved the video surveillance business. DVRs have allowed for easier remote viewing, virtually unlimited storage of video data and, when used as an off-site management tool, increased production. Because recording is stored on a hard drive instead of video tape, physical storage space is saved and off-site data archiving is possible over a network. In order to properly design, install, and maintain these systems, you must have a good grasp of the technology.

To determine your level of knowledge of digital video recorder technology, take our 20 Questions quiz. Then turn to page 30 to find out how you scored.

1. Digital video recorders record on digital videotape.
   1. True
   2. False
2. Real time recording rate is considered to be
   1. 1 frame per second.
   2. 15 frames per second.
   3. 30 frames per second.
   4. 15 frames per minute.
   5. 30 frames per minute.
3. Hard drive size on a DVR will determine
   1. data storage time.
   2. how many frames per second at which cameras can be set to record.
   3. concurrent client-viewing connection availability.
   4. bandwidth usage.
   5. none of the above.
4. Which operating system is required to view a DVR’s cameras over a network?
   1. Windows 98
   2. Windows 2000
   3. Windows XP
   4. Apple 9.0
   5. Depends upon the viewing application
5. All DVRs use the same operating system.
   1. True.
   2. False.
6. For general security purposes, the most efficient use of recording space on a DVR can be attained by setting the DVR to:
   1. record on weekdays only.
   2. record constantly.
   3. record on motion/activity detection only.
   4. record on a schedule.
7. Bandwidth is not a concern when viewing a DVR’s cameras over a network.
   1. True
   2. False
8. All DVRs record using bmp video compression.
   1. True
   2. False
9. When calculating for the amount of storage time on a DVR it is important to know
   1. the desired frame rate of the cameras being recorded.
   2. the hours of operation of the customer’s business.
   3. the number of cameras to be recorded.
   4. All of the above
10. To record properly DVRs must be set to record on a prearranged schedule.
    1. True.
    2. False.
11. Which of the following cameras can be recorded on a DVR?
    1. IP cameras
    2. black-and white-cameras
    3. high-resolution color cameras
    4. Any of the above
    5. None of the above
12. All DVRs have the same storage capacity.
    1. True
    2. False
13. When integrating a DVR with a burglar alarm system, the alarm outputs of the burglar alarm would be connected to the DVR’s ________ to trigger alarm recording.
    1. camera video inputs.
    2. camera outputs.
    3. alarm inputs points.
    4. parallel input port.
14. Which of the following is an advantage of DVRs over VCRs?
    1. Physical space needed for storage of recordings
    2. Speed of searching an event
    3. Ability to easily send and print images
    4. All of the above
15. Which DVR has the larger theoretical storage capacity?
    1. 10 kilobyte drive
    2. 2 terabyte drive
    3. 540 megabyte drive
    4. 1,000 bit drive
16. The video output of a camera should be connected to the video _______ of the DVR.
    1. output
    2. input
    3. alarm output
    4. comm port
17. Color and black-and-white cameras never should be used on the same DVR.
    1. True
    2. False
18. For ease of remote viewing over a network, it is important to have a fixed IP address set in the DVR.
    1. True
    2. False
19. DVRs are only viewable on a customer’s internal network.
    1. True
    2. False
20. After setting a DVR to record on motion/activity only, the best way to check that your settings aren’t triggering falsely would be to
    1. search for events recorded/triggered when there is no motion/activity.
    2. search for events when there is motion/activity.
    3. check your schedule settings.
    4. None of the above.

Check your answers: Field Guide - 20 answers about dvrs.

Why Is this not the Preferred Way to Install?

The security industry’s bane installer, Wally ‘Larman, installed a video surveillance system for a client that included a DVR, dome camera and an analog CCTV monitor viewing station at a receptionist’s desk. He connected the devices as shown in this diagram. While this approach will work, it is not the best way to accomplish the task. Can you see what Wally can do to make the system work better and be more flexible?

Answer: 20 answers about dvrs.

What’s Wrong with T-tapping?

Wally ‘Larman installed a video surveillance system that included a DVR, dome camera, and an analog CCTV monitor viewing station. Because the camera and DVR were a long distance apart on opposite sides of the facility, Wally T-tapped the video output of the camera to complete the job faster and go home early. What should Wally have done to properly install the system?

Answer: 20 answers about dvrs.