Communications Specialties Application Note

USING COMPUTER-TO-VIDEO

SCAN CONVERTERS IN

SECURITY APPLICATIONS

MARKET: Security

DOC. NUMBER: T-03

Security and surveillance environments today often make use of personal computers (PCs) for monitor-

ing and displaying the status of access control systems and alarm conditions. Often times, these PCs are

located in remote locations, such as equipment rooms or utility closets. These types of inaccessible

locations make viewing the displays from the computers inconvenient and impractical.

Rather than move the location of the computer to a less secure, more obtrusive location, there is an

easy way to allow viewing of the computer’s output on a standard, inexpensive video monitor, located

wherever monitoring would be most convenient and effective. This TECHnique describes how

Scan Do

Select, Communications Specialties’ small, low cost and easy-to-use computer-to-video scan

converter, can be used for just this application.

Most surveillance and access control

systems already have some form of a

CCTV installation in place. Video cam-

eras, placed around and within a prop-

erty, transmit their video signal over coax

or fiber optic cable to one or several cen-

tral monitoring stations. However, the

video signal, as generated by personal

computers, is not in a format conducive

for transmitting over such a system, nor

can it be viewed on standard video moni-

tors. This is where a scan converter is

necessary.

Scan Do Select enables you to con-

vert any PC’s monitor output to a stan-

dard video (TV) signal, which can easily be inte-

grated into an existing CCTV environment. By con-

verting the computer video into standard NTSC or

PAL format and then transmitting it to a central

monitoring station, security personnel are able to

view the video output from the PC right on the same

types of video monitors used to view other surveil-

lance activities.

The accompanying diagram illustrates how

Scan Do Select might be added to this type of se-

curity system. Note that multiple monitoring loca-

tions may be established for viewing the PC’s out-

put. In addition, Scan Do Select allows for the con-

tinued use of the PC’s monitor at the location of the

computer, allowing for easy maintenance and inter-

active computer use.

The video signal from Scan Do Select (and from

any surveillance cameras) may be routed to the

monitoring area using either standard coaxial cable,

or with fiber optic cable. For applications such as

this, CSI offers an extremely cost-effective fiber optic

video transmission system, called Beamer-V

which transmits a high-quality video signal up to 1.5

miles over standard multimode fiber optic cable.

Because the picture quality on video monitors is

never as good as on computer monitors, you may

Scan Do is a registered trademark and Beamer-V is a trademark of Communications Specialties, Inc.

Communications Specialties Application Note

Page 2: USING COMPUTER-TO-VIDEO SCAN CONVERTERS IN

SECURITY APPLICATIONS

find that the PC’s output, after being converted by

Scan Do Select, lacks some of the small detail vis-

ible in the original computer image. However, by

using a high-quality video monitor, you should find

that the alarm, sensor and conditional access infor-

mation is easily readable even after the conversion.

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Scan Do Select ......................................... 1290

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Beamer-V .................................................. 3105

If color information is not critical, a high-resolution

security black and white monitor may be used. You

may also opt to use an existing camera monitor and

feed the Scan Do Select’s output into a switcher or

sequencer along with the camera feed to save the

cost, and space, of an additional monitor. If avail-

able, use a monitor with an S-video input for the

highest resolution display. You can also record the

PC’s display information in either real time or with a

time-lapse recorder for later review.

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Educational Guide on Scan Converters

•

T-10 Using computer video and video splitters

in security applications