On 2014-05-18, Pete Keillor wrote:
On 18 May 2014 02:51:57 GMT, "DoN. Nichols"
wrote:
[ ... ]
I used the 50 pin version on one rig in R&D. Over my career, I moved
from massive quantities of H-9 hose (pneumatic instruments) to poly
tubing to direct wired, to 37 pin Amphenol connectors (with the crimp
insert pins) to the 50 pin D connectors. Then finally to networked
connections.
37-pin Amphenol in the D series (e.g. DC-37)? Amphenol makes a
wide range of connectors -- including the "miniature circular) ones
which used to be made by Bendix, and made with the connectors on the back
of aircraft instruments from the 1967 period.
BTW -- Amphenol started out as "American Molded Phenol" -- the
blue plastic used as insulators in many of their early connectors.
The Amphenol connectors came on my first cart rig, where I could roll
carts with different capabilities in and out to the main line. The D
connectors were much easier to use, because we used them on ribbon
cable. I also had a few failures on the Amphenols due to faulty
insertion or removal techniques.
Some Amphenol connectors (in the "miniature circular" style) are
available as "scoop-proof". (That is, the male pins are recessed far
enough so the female connector can't reach into the shell far enough to
bend them -- but once the keys are properly aligned, the whole thing
goes in straight to connect reliably.
My last rig in that style had about
1000 individual wire terminations in the main cabinet. I'd land the
ribbon cables on a breakout board, cross wire to the computer I/O
boards. Made it easy to add and modify instrumentation.
That helps, indeed.
The networked rigs were a quantum leap forward. I was able to make
location independent carts which could be used (or not) anywhere in
the pilot plant, and no long runs of signal wiring anywhere other than
the coax or optic fiber network.
Yes -- each device has its own address (MAC address, as well as
likely IP address), and they can all talk to either other on one cable,
assuming that nothing is overloading the bandwidth of the ethernet hose.
There was talk of wireless when I retired, but I concluded that was a
bad idea in the chemical industry. Maybe I was just too old
fashioned, but the thought of someone interfering with a potentially
dangerous process with a cell phone or appliance, or intentionally by
some other means made me very nervous.
I happen to agree *fully* with you. Even if they don't try to
set up a second wireless network overlapping the first in coverage. :-)
Just as using wireless keyboards and mice is a bad idea where
more than one computer is in use. (I'm sort of considering a wireless
trackball on this computer, but I can't let my wife have on at the same
time. Were sitting about eight feet apart, and the computers are closer
to each other. :-)
Enjoy,
DoN.
--
Remove oil spill source from e-mail
Email: | (KV4PH) Voice (all times): (703) 938-4564
(too) near Washington D.C. |
http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---