Dear All,
Thanks for the useful information some of you provided regarding multiple
displays. Here is a brief summary.
1. Monitor Switchbox (my way)
I hooked two SGI monitors to a SGI-O2 using a monitor switchbox
with one IN-port (to computer) and two OUT-ports (to monitors). Only one
monitor displays at a given time, which is what I want. The box costs only
~$9 (see.
http://www.cablesonline.net ). The disadvantage of this kind of
design is the wake-up time of monitors (~30s) after switching. I don't mind
of waiting since switching takes place not very often.
2. BNC connection:
We do this all the time on our spectrometers (Bruker DMX400
and ABX Biospec 1.9T). The easiest way to connect multiple displays
to one computer, regardless of whether the computer is a SGI, Sun, or
PC, is to start with a cable from the computer which ends with four
or five BNC sockets. Cables of this type are available for HD15
(three row 15 pin) and 13W3 (two row with 3 coaxial pins) video
connectors from L-COM (www.L-com.com). Sometimes (when the computer
and monitors are configured for "Synch on green", a three-BNC cable
is sufficient. Connect a BNC T fitting to each of the BNC sockets and
attach these to the BNC plugs on the back of the first monitor, if
the monitor has these. If not, then get another HD15 or 13W3 to BNC
cable for the monitor. The second monitor is simply daisy-chained
from the first monitor, using BNC cables (ideally with 75 ohm
impedance) from each T connector. You can continue this sequence with
additional monitors, depending on the current output of the
computer's video board, with the BNC cables plugged directly into the
last monitor, i.e. without any T fittings. Finally, set the input
impedance of the final monitors to 75 ohms (low) and all other
monitors to high impedance. In this way, the last monitor in the
chain "terminates" to chain, preventing the video signal from
reflecting back to the other monitor(s). If you don't get a picture
on each monitor, try disconnecting HSYNC, VSYNC, or both HSYNC and
VSYNC BNC's from the computer. Please let me know if you have any
problems.
3. VGA-Video-Splitter
We need a second monitor at a SGI-O2 nearby the magnet (for easier
handling of wobble).
We solved the problem with an "VGA-Video-Splitter", which allows to
connect up to 4 monitors simultanously (maybe that there exists models
with more outputs).
Unfortunatally this device is not cheap (700 DM, 350 Dollar), but it
works fine (without disturbing any screen picture, like glittering,
shaddows or some others)
4. web-site:
If you are using Suns, try looking at :
http://www.cs.brown.edu/software/xmx/home.html
Jerry Hu
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Jerry Hu, Ph.D. email: jghu_at_mrl.ucsb.edu
RD Engineer Tel: (805)893-7914
Materials Research Lab, UCSB Fax: (805)893-8502
Santa Barbara, CA 93106
Received on Wed Jul 19 2000 - 18:59:38 MST