At 03:48 PM 1/9/99 -0600, Doug Yowza wrote:
>Hey, any industrial controller collectors out there? I didn't think so.
Well, I am. That's part of my job experience -building/maintaining
industrial controls. Allison has experience in this too from what I recall
from her past discussions here. A few others may lurk behind the trees too.
>
>I just picked up an exceedingly cool 486 box from around 1993 with a
>touch-screen LCD and ethernet. The entire machine is about the size of an
>Amiga box, but it's in a black hermetically sealed magnesium case. It's
>running QNX 4.11, and root didn't have a password (woohoo!). The Li
>battery was starting to ooze corrosive juices onto the CPU, but other than
>that, it's in primo shape.
Clean up that mess. I'm not sure so far but I think that battery juice is a
bit toxic. Be careful nevertheless.
What kind of manufacturer names are on this thing?
>
>I have some stupid questions:
Not really stupid in this case; you're just new to it. :)
>
>Was there a GUI for this version of QNX? I can't find one, nor anything
>that exploits the touch screen on this box.
There are third-party GUI's possibly available for QNX but they are costly.
Wonderware's and Intellution's interfaces are around US$2k minimum for
example. There may be others cheaper nowadays. These GUIs are typically
refered to in the industry as Man-Machine Interface or MMI.
QNX is a small realtime OS for control systems. Applications are nearly
always handwritten for each installation often using a third-party supplied
MMI, etc. No typical desktop apps available for QNX as far as I know. I
know little about QNX and my books and catalogs are still packed in boxes
after my untimely "downsizing" last year.
>
>There are three fans inside the box, but it's sealed. I always thought
>that fans worked by exchanging hot air for cooler air. What good are
>fans inside a sealed box?
The industrial environment is quite tough for electronics. Depending on the
factory/machine/process, much muck could be drawn into an electronics
enclosure by air circulation. In machine shops as an example, tool coolants
which are sprayed onto the workpiece and tool are found in the air as an
aerosol mist. The aerosol is pulled into a cabinet by the fan and collects
on everything. Over time there is a coating of condensed coolant which
collects dust and other garbage and prevents proper cooling of critical
components. I worked on a 1978 vintage 6800-based CNC controller (not 68k,
but Moto's 6800 :) which had this cooling arrangement. After about 12 years
I found a 1 mm thick coating of sticky coolant glop coating most everything
that was not even close to the airstream of the cabinet cooling fan. Poor
idea. A standard PC used in most machine shops is even asking for trouble
after a period of time.
Sealed Boxes Are Good. Cooling is achieved by thermal exchange between the
outer surface of the enclosure and the surrounding atmosphere. Fans inside
the box ensure the air is mixed to maintain contact with the inner surface
and to prevent "hot spots".
On systems which had to have a LOT of electronics, especially high power
motor drives and a CRT display, etc. a refrigerated heat exchanger system
was hung on the outside of the cabinet with its cooling surface stuck
inside the enclosure. Another lower cost, simpler way is to use the
venturi-effect which uses filtered compressed air blown through a venturi
thus cooling the air and pressurizing the control cabinet. Air was
exhausted _out_ of the controls because of the positive pressure inside.
Really old machines actually had a small air conditioner placed inside the
cabinet.
Usually when I built control systems I made sure I could get as much
surface area as possible exposed to the outside world. I used cabinets
somewhat larger than needed, air moving within, free space around exterior
and absolutely no open apperatures to let junk in. Insides were kept clean
with fewer electronic failures.
Some non-industrial computers that have no fans, especially lo-cost
mass-market types, probably had their cases made such that free flow of air
around the exterior would help cool things off without relying solely on
their vent holes and slots.
>
>Long shot: the display blanks after a few minutes, and hitting a key (it
>has a keyboard port) or touching the screen doesn't unblank it. Any
Hard to tell without knowing something about the software written for the
thing. Of course, it is not hung on the original machine at this time so
there could be some sort of interconnection which would keep the controller
running. Though the display blanks this could be related to a feature in
just the display panel, not so much the controller. I feel the CPU is
halted early on as there are no periferals to be found, so the OS hangs
thus not keeping the display 'alive'.
>guesses on how to wake it back up (BTW, there's no power switch on this
>thing -- it wants to be on *all* the time).
24/7 is the norm for most industrial systems. The power switch for this
machine was likely the big disconnect switch on either the machine or the
wall from which the AC power was run to from an overhead busbar. You never
shut it off unless there was an extended plant shutdown (long vacations) or
machine repairs.
I haven't got Netscrape back up yet because of a disaster with windoze95
(GRRRR! Don't get me started on this damned OS which cannot handle system
problems correctly. The crash was incredibly uncalled for and troublesome.
Grrrr.....) but I would suggest searching for a QNX website yourself. They
could have some bits of info for you to pick out. Otherwise, as an
"unlicensed end user", you may not get any direct help from them. They will
likely send you to a local sales rep. Depending upon how sympathetic he/she
is to you being a collector type you _might_ get a little assistance or
even a few bits of documentation.
Good luck.
-- Chris
-- --
Christian Fandt, Electronic/Electrical Historian
Jamestown, NY USA cfandt_at_netsync.net
Member of Antique Wireless Association
URL:
http://www.ggw.org/freenet/a/awa/
Received on Tue Jan 12 1999 - 10:08:49 GMT