Building Auto- Voice-Data-Video (VDV) System Control Devices and Applications

Public Switched Telephone Network (PSTN)

A network of telephone exchanges that can be connected together to make a continuous circuit for each telephone call.

Camera Lenses

focus light reflected from an object within its field-of-view on an image sensor, which converts the light information into electrical signals.

Bit Rates and Baud Rates

if the transmitted electrical signals from a telephone are greater than one bit in length, then the bit rate is greater than a corresponding baud rate.

Telephone Handset

includes a microphone and a speaker that convert sound pressure waves to an from electrical signals.

The simplest CCTV system consists of:

just a camera and a monitor, although most systems also include a recording device.

Network DVRs

record digital video information on storage media that is accessible via the local network.

Time-Lapse Recording

records video images at a fraction of the frame rate of real-time recording.

Multi-Image Monitor

CCTV systems with many cameras typically display multiple video feeds on a single monitor simultaneously.

Voice-Data-Video (VDV) systems include:

Telephony, data network, and closed-circuit television (CCTV) systems.

Analog Video Image Signals

are composed of lines of information.

Digital Video Image Signals

are composed of pixels.

Telephone Line Seizure Devices

are installed upstream of any other telephone devices within the premises so that if necessary, an emergency control panel can take control of the line.

DTMF Signaling

can be used to send control information accross telephone lines.

Telephone Hook Switch

changing the position of a telephone hook switch changes the operation of a telephone.

Private Branch Exchanges (PBXs)

connect in-house telephones together within a private network and manage the telephones' access to the Public Switched Telephone Network (PSTN).

Field-of-view

control of the field-of-view of a camera involves changing it's position and zoom level.

DTMF tones

each telephone keypad digit responds to a pair of DTMF tones.

Focal Length

the focal length of a camera lens determines how much area is covered by the camera.

Pan-Tilt-Zoom (PTZ) Cameras

the position and zoom level of a PTZ camera is controlled by a PTZ controller keypad. These cameras can be controlled by other building systems.

Telephone Line Seizure Modules

use special jacks that open the connection between the premises wiring and the telephone line, inserting a dialer into the circuit.

Voice over IP (VoIP) systems

use special telephones that convert voice audio into packets of digital information to be transmitted over the internet.