Real time video:
is a picture with more than 24 frames per sec and therefore looks continuous.

Receiver driver:
is a part of the matrix switcher placed at the camera point and connected to the main switcher by a twisted pair cable. It is used to decode the incoming control signals for the Pan Tilt Zoom functions.

Reed switch:
is a type of alarm activated when the contact is opened or closed . It is widely used with doors, windows, roller shutters etc. and can also activate a switcher to bring the nominated camera up for extended viewing.

Regulated power supply:
is a type of DC power supply in which the ripple factor is minimal.

Remote head camera:
is a type of camera in which the CCD chip is separated from the camera body by cable. It is used in applications where the amount of space is limited.

Resolution:
is a measure of picture definition and clarity and is represented by number of lines. Greater the number of lines, higher the resolution.

RG-11:
is a type of coaxial cable with a thicker centre core and used for transmission of video signals up to 550m.

RG-59:
is a type of coaxial cable used for transmission of video signals up to 230m. It is the most popular cable used in CCTV.

Ripple factor:
is the amplitude variation present in a DC power supply due to insufficient filtering . A large variation can damage a DC camera.

RS-232:
is a communication protocol used for communication between microprocessor based devices.