Rockwell Automation 6153 Industrial Computers (6153, 6154) - Manual (Page 16)

Bulletin 6153 and 6154 Industrial Computers with Integrated CRT 16
Publication 6153-2.0
Contrast and Brightness Controls
The Bulletin 6153 and 6154 Industrial Computers are equipped with
adjustable contrast and brightness controls. The 4-slot units have
duplicate controls on the front and the back of the unit. The 8/12-slot
units have a contrast control on the front, and both contrast and
brightness controls on the back.
To obtain the best display:
•
set the contrast control for comfortable viewing under lighting
conditions that match those in which the Industrial Computer will
be used.
•
adjust the brightness control to increase or decrease the video
image’s intensity as required.
Raster Rotation
A raster rotation control is located on the back of the unit. It allows
you to correct display misalignment which might result from
interaction between the monitor and an external, low level uniform
magnetic field, such as the earth’s magnetic field.
All CRT displays are affected by the earth’s magnetic field and by
similar low level uniform fields. Generally, the effects of such a field
on the display vary with the display’s spatial orientation relative to
the field lines. For, example, when the Industrial Computer’s screen
is facing West, the effects of the earth’s field are minimal, but when
the screen is rotated toward the North or South the display itself can
exhibit a small amount of rotation, so that its top and bottom edges
are no longer parallel to the edges of the panel.
Note: This effect is different from the effect of magnetism on the
shadow mask, which takes the form of color impurity and is
corrected by the degaussing system described previously.
Before making any adjustment, display a full screen image and check
for rotation (top or bottom edge of the image out of parallel with the
corresponding edge of the panel).
If adjustment is necessary, turn the control knob while observing the
display (in a mirror if necessary) to adjust the image alignment.
Important: The raster rotation control cannot correct for the effects
of external AC fields such as those produced by large motors,
generators and transformers. Such effects often take the form of
display jitter. Protection against this kind of magnetic interference
requires special shielding.
Image Size and Position
Controls for Vertical Size, Vertical Position, Horizontal Size, and
Horizontal Position are located on the back of the unit. Use this
controls as necessary to adjust the image.