Colour Display System SEMIGRAF 240 - The history of Ericsson

Colour Display System
SEMIGRAF 240
Bjorn Karbeus
This article presents the new computerized colour display system SEMIGRAF 240.
which replaces conventional types of control panels. SEMIGRAF 240 has been
developed by SRA Communications AB, a member of the Ericsson Group.
UDC681 326:
621.397 132
Fig. 1
Control room with display units that form the
opera tor pane I for control of an ore dressing plant
The transition from the earlier manual
control and supervisory systems of various
types to computerized systems
makes new demands on the units that
transfer orders and information between
operator and system.
For a long time various types of control
panels with instruments, switches and
controls provided the normal solution.
In large systems such control panels can
be very extensive, and can sometimes
take up a whole wall. They are therefore
expensive and difficult to change. An
improvement was achieved by introducing
various types of black/white graphic
displays as operator units. The operator
could then fetch information from the
system, and also control it by feeding in
various commands. However, in many
cases it proved to be difficult for an
operator to assimilate the displayed information
quickly and correctly. The introduction
of colour as an aid in the
structurization of the displayed pictures
made it very much easier to recognise
and understand the information shown.
Background
SRA Communications AB have worked
on different types of displays, both
black/white and colour since 1969.
SEMIGRAF is the registered trade mark
for colour display systems manufactured
by SRA.
The first system, designed SEMIGRAF
210, was delivered in 1974 and since
then many systems have been supplied
for a number of different applications,
such as power supervision, ore dressing,
railway control and supervision of
coaxial cable networks.