what is VGA?
What is VGA?
VGA stands for “Video Graphics
Array.” It has been the standard
monitor or display interface used in
most PCs for many years. VGA is
being supeceded by new technology
such as HDMI and DisplayPort, but
still remains popluar. Therefore, if a
monitor is VGA-compatible, it should
work with many new computers
and almost all older ones. The VGA
standard was originally developed
by IBM in 1987 and allowed for a
display resolution of 640x480 pixels.
Since then, many revisions of the
standard have been introduced.
The most common are Super VGA
(SVGA), which allows for resolutions
of 800x600, and XGA at 1024x768. A
standard VGA connection has 15 pins
and is shaped like a trapezoid (please
see below)
How long can a VGA cable be?
It was originally designed for very
short runs of a metre or so to connect
a PC to a screen, but due the evolution
of computer technology, the most
common use is to connect a laptop
to a screen in a typical boardroom
or meeting room. This has presented
a challenge for AV companies as
well as Soft Wiring specialists like
ourselves at OE Electrics. As a result,
we have had our own VGA cable
made to exacting specifications and
can supply at either 1.8m, 3m or 5m
lengths.
We recommend a total cable length
of source to screen of no more than
7.5m. This includes the cable used to
connect the source to our unit.
What can affect the image quality?
There are two factors that greatly
affect the image quality. One is the
VGA driver or display card inside
the computer. Many are designed
to drive over short distances and do
not perform well above 5-10m. The
other is the cable itself. VGA is a hiresolution video signal and demands
a properly designed cable, such as
the one, we at OE Electrics have
specifically made for us. Each of the
signal cores inside the VGA cable is
individually screened to prevent signal
degredation, and the VGA connector
pins are gold plated for improved
contact.
1 Calder Point, Monckton Road Industrial Estate,
Wakefield, West Yorkshire, WF2 7AL
Tel: +44 (0) 1924 367255 Fax: +44 (0) 1924 290652
Email: [email protected] www.oeelectrics.com
London
-
Dubai
-
Sydney
WhatisisVGA?
VGA?
what
What if I need more than 7.5m?
There are two main ways to increase the overall cable
length:
1.
VGA booster/amplifier. This would be a unit fitted
in-line with the VGA cable, some manufactures claim a run
of up to 70m can be achieved. Some boosters can take
their power from the VGA cable itself, others will need an
external power supply, a provision for which would have to
made for under the desk.
2.
VGA to Ethernet adaptor. VGA over IP (Internet
Protocol) gives, in theory, an unlimited cable run if routed
through a main server room. A small converter box, usually
powered by the VGA circuit, is needed at each end of
the cable run to encode and decode the signal which is
transmitted along standard data cable such as Cat5e. This
can be a very useful way of sending the signal around the
building if you wanted to use multiple screens or even for
digital signage on the front of a building or in the reception
area.
OE Electrics recommend VGA cables be no
more than 7.5m in length
Cable C
(supplied by others)
A+B+C = MAX 10m
Cable A
Keep to minimal length (e.g. 1m)
(Supplied by others)
Cable B
1.8m, 3m or 5m cable
(supplied by OE)
no more than 2 connection points
1 Calder Point, Monckton Road Industrial Estate,
Wakefield, West Yorkshire, WF2 7AL
Tel: +44 (0) 1924 367255 Fax: +44 (0) 1924 290652
Email: [email protected] www.oeelectrics.com
London
-
Dubai
-
Sydney