On 19 May 2014 02:48:53 GMT, "DoN. Nichols"
wrote:

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.

No, it was one of the green round shell ones, about 1" or a little
bigger in diameter. You had to crimp the tiny little mating bits on
each wire with an expensive tool that did a circular crimp, then
insert in the connector.

Bad choice on my part, drove us nuts keeping all the signals straight.
D connectors and ribbon was a lot better. I found quick release
latches for the D's, plus shielded ribbon cable which was rolled up in
the shield and outer insulation. I mounted the mating connectors in
the bottom of 6" Hoffman hinged trough suspended overhead.

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.

I'm going to try one of those on a current project. I'm trying to put
together a cheap, very simple to operate cd voice recorder. I'll use
a headless microcomputer to run the show, interface with pushbuttons
only. I'll use a monitor, keyboard, etc. to develop, test, and down
the road if this works, repair.

My wife volunteers with some folks in women's prisons here in Texas
recording inmates reading children's books to their kids, then sending
the recordings and books to the kids. They used to use cassettes, but
can't find the players any more. They're changing to cd's, also
obsolete, but at least cd's are cheap and available. The problem is
the volunteers are using laptops and recording thumb drives, and about
half the volunteers have difficulty running the recording, file
conversion, burning, etc. Never mind the inevitable bloatware and
pop-ups.

We looked all over for cheap voice recorders with cd capability. They
exist, but not cheap. So I'm trying a $45 Beaglebone Black, $12 cd
burner, then I'll probably need a custom cape to handle audio, mic and
speaker, buttons, and battery management. Code will be the big deal.
I need auto-start and a graceful shutdown. Don't need no stinkin'
network, etc. Except for troubleshooting and repair, and that won't
be accessible to the users. I've got a lot of learning to do. And
networking (not my strong suit) to find the right help. Ultimately
they'd need over 30 of these. They cover six prisons once/month.

Pete

Pete Keillor