How Does CCTV Work ?
There are many different types of CCTV systems available—analog and digital, wired and wireless—and their modes of operation vary; however, the basic components are in essence the same: a CCTV camera, a CCTV camera lens, a CCTV monitor, and (for wired systems) cables that carry the signal from one place to another.
The images collected are sent to a CCTV monitor and recorded on video tape via a VCR or as digital information via a DVR (Digital Video Recorder). The CCTV camera lens will determine how far and much detail the CCTV camera can see.
The CCTV camera picks up the signal from the area being monitored, and in a wired system, the CCTV camera sends the signals through a coaxial cable to the CCTV monitor; in wireless systems, no cable is needed, instead the CCTV camera broadcasts the signal. Monitors can be watched by CCTV controllers or left unmonitored.
Recent advances in technology and software mean many DVRs are now equipped with advanced features such as Motion Recording and Event Notification. When set to motion record devices will only record when the CCTV camera detects motion. This saves storage space because the device is not recording during periods of inactivity. Event Notification is the process of sending a text message, recorded telephone messages or email when motion is detected.
This is particularly useful for unmanned systems. The recorded information can be stored and/or reviewed by those who have access to the recordings at their convenience. Many of the latest DVRs also have network connections so that saved and live footage can be accessed remotely via a PC over the internet.