CCTV Video Controllers
Video Switching Systems
If a CCTV system has more than one camera, there must be a way to control each video signal going to the recording device and the monitor. As do the applications and designs of CCTV systems, video switching units come in a wide variety of styles.
Sequential Switchers
Unit that provide full screen images, one camera after another, typically for 3 to 5 seconds each. When one camera is on the screen the other cameras are not being recorded. The major drawback is the time loss factor between camera images recorded (i.e. In an eight camera system, at 5 seconds of delay between images, there is 35 seconds of time loss from the point that the system switches from camera #1 to the point that the system returns to camera #1. Video sequential switchers also have severe limitations in controlling multiple PTZ devices.
Quads
Units that were originally designed to promote visual verification of up to four video images on a signal screen. Designed to display four images of 150 horizontal lines of resolution at a time, these units were not designed to be used for recording of the images in higher resolution applications.
Multiplexers
These units are high-speed switchers that provide full-screen images from up to 16 cameras. Multiplexers can playback everything that happened on any one camera without interference from
the other cameras on the system.
Matrix Switchers
These units are designed to ‘manage’ large numbers of cameras and monitors. Usually used in systems of minimum 12 cameras, they are able to expand into the thousands of camera inputs and hundreds of monitor outputs. Each camera input and monitor outputs are completely independently programmable. I.e.; Monitor #1 will display all of the odd camera #s in a sequential mode. Monitor #2 will display all video alarms from the odd numbered cameras only. Monitor #3 will display camera image number 4 only. Matrix switching units have many other programmable features such interfacing to access control systems, user log-ins, and PTZ control.
If a CCTV system has more than one camera, there must be a way to control each video signal going to the recording device and the monitor. As do the applications and designs of CCTV systems, video switching units come in a wide variety of styles.
Sequential Switchers
Unit that provide full screen images, one camera after another, typically for 3 to 5 seconds each. When one camera is on the screen the other cameras are not being recorded. The major drawback is the time loss factor between camera images recorded (i.e. In an eight camera system, at 5 seconds of delay between images, there is 35 seconds of time loss from the point that the system switches from camera #1 to the point that the system returns to camera #1. Video sequential switchers also have severe limitations in controlling multiple PTZ devices.
Quads
Units that were originally designed to promote visual verification of up to four video images on a signal screen. Designed to display four images of 150 horizontal lines of resolution at a time, these units were not designed to be used for recording of the images in higher resolution applications.
Multiplexers
These units are high-speed switchers that provide full-screen images from up to 16 cameras. Multiplexers can playback everything that happened on any one camera without interference from
the other cameras on the system.
Matrix Switchers
These units are designed to ‘manage’ large numbers of cameras and monitors. Usually used in systems of minimum 12 cameras, they are able to expand into the thousands of camera inputs and hundreds of monitor outputs. Each camera input and monitor outputs are completely independently programmable. I.e.; Monitor #1 will display all of the odd camera #s in a sequential mode. Monitor #2 will display all video alarms from the odd numbered cameras only. Monitor #3 will display camera image number 4 only. Matrix switching units have many other programmable features such interfacing to access control systems, user log-ins, and PTZ control.