Video systems can consist of a single camera and monitor or might include hundreds of cameras and multiple monitors. Frequently, video equipment such as multiplexers, matrix switchers, VCRs, or DVRs also may be included to provide on-site or remote viewing and control of the cameras. To find out if you clearly see video technology, take the following quiz.

1. Video systems used in the United States follow the PAL standard.
a. True
b. False

2. What is the typical connector used today for analog video connections?
a. BNC
b. PL259
c. Type N
d. None of the above

3. Which of the following cable types can be used to transmit video signals?
a. Coaxial cable
b. Fiber-optic
c. Cat 5
d. Any of the above

4. A matrix system allows multiple users to control:
a. which cameras are viewed.
b. PTZ functions of cameras so equipped.
c. video guard tours.
d. All of the above

5. PTZ functions of a camera cannot be controlled using a multiplexer.
a. True
b. False

6. What is the correct termination for analog video signals?
a. 25 ohms
b. 50 ohms
c. 75 ohms
d. 100 ohms
e. None of the above

7. One rack unit (RU) is equal to approximately 1.75 inches of vertical space.
a. True
b. False

8. Both multiplexers and matrix switchers provide video out- puts that allow a single VCR to record multiple cameras.
a. True
b. False

9. Which of the following inputs would be used to connect the BNC output of a multiplexer to a monitor?
b. RGB
c. Analog
d. S Video
e. Any of the above

10. DVRs cannot be used with multiplexers.
a. True
b. False

11. Which of the following lens will provide the widest angle view?
a. 80mm
b. 25mm
c. 2.5mm
d. 8mm

12. Computer monitors cannot be used to display analog video images.
a. True
b. False

13. "T" tapping is the proper method to connect multiple monitors to a single video source.
a. True
b. False

14. As you increase the f-stop, the amount of light entering the camera also will increase.
a. True
b. False

15. Matrix systems allow a user to control multiple:
a. cameras.
b. monitors.
c. VCRs.
d. All of the above

What's Wrong with This?

Wally `Larman installed eight cameras with a multiplexer, VCR and monitor. He ran the correct cables, used crimp-on connectors and wired the devices as shown in this diagram. After setting the multiplexer to display all cameras on the monitor, Wally set the VCR to record. After a few minutes of recording, Wally was able to play back the images, but when the customer checked the installation, he was not happy. Can you see what Wally did wrong and what he must do to correct the problem?

5-Minute Tech Quiz Answers

Here are the answers to What's Wrong with This? and the 5-Minute Tech Quiz that appears on Page 47.

1. b - In the United States, video systems follow the NTSC standard. PAL is used in Europe.
2. a
3. d
4. d - Matrix systems allow an authorized user to select which cameras are viewed on any monitor in the system and control PTZ of cameras and video guard tours. The PTZ control may be limited depending on the manufacturer of the matrix and PTZ.
5. b - Multiplexers can control PTZ functions of cameras. As with matrix systems, PTZ control may be limited depending on the manufacturer of the multiplexer and PTZ.
6. c
7. a - Rack units (RU) is a means of determining how much vertical space the equipment will need.
8. b - While a matrix can provide video tours or multiple images on a single monitor, the multiplexer is designed to combine all camera images on a single VCR.
9. c
10. b - You can use a single-channel DVR with a multiplexer as long as the DVR is compatible with the multiplexer.
11. c
12. b - Some computer monitors have additional inputs that can accommodate analog video or other video sources.
13. b - "T" tapping should not be used for video signals. Use either looping outputs or distribution amplifiers.
14. b
15. d

Answer to: What's Wrong with This?

Wally's problem is caused by the way he connected the VCR. By connecting it to the monitor output, it will record whatever is being displayed on the monitor but will not allow the user to bring a single camera to full screen. Wally should reconnect the VCR to the VCR in and out terminals as shown in this diagram.

In this way, his customer can get the full benefits of the multiplexer, such as the ability to change which cameras are displayed on playback. In addition with the original configuration, if someone changed the monitor output to a single camera, the VCR would record only that camera. However, when wired correctly, all cameras will be recorded regardless of what is being displayed on the monitor.