Re: deploying patch cords

On 7/3/2025 8:36 AM, Theo wrote:

Don Y <blockedofcourse@foo.invalid> wrote:

I want to allow for the possibility -- in an unusual situation -- for
1 to be broken from 1 and mated to 82, instead.  E.g., if the mated 1
malfunctions.
>
But, this would be a "singleton" connection that could easily stand out
among the more orderly other connections.
>
The sandwich illustrated relies on lots of very short patch cords.
This keeps things dressed nice and tidy.  But, may require care in
their manufacture -- e.g., if you plug in one end and have only
a few inches of service loop to ensure the other end is *oriented*
in the correct direction.
>
It also means you'd need a few "exception handlers" -- longer cords
to deal with the 1-to-82 case alluded to above.

 If you provision your installers with a bag of (say) 100x yellow 0.2m cables
and a bag of a much smaller number of red 0.5m cables (let's say 4, in this
example), the short cables will get used for the vertical links and the long
red cables will get used for the links out of sequence.  That way the ones
that are unordered will stand out and be easy to identify.

You don't worry about an "installer" -- he'd (supposedly) be cosen
for his competencies.
What you worry about is the *user* making changes to the wiring,
typically because he sees something undesirable happening,
wants to make a change or has been directed to make a *specific*
change (by the system or by a remote troubleshooter).
E.g., "move the A end of cable 137 to the unused A connection 205."
Or, "swap the B ends of cables 128 and 52."
He would have to be able to execute this correctly with no
technical training -- possibly blind, possibly confined to a wheelchair,
etc.

I expect that even the dumbest installer is not going to fit links 1-4 with
the long red cables and then links 5-80 with the short yellow cables.  And
there will be a certain physical limit to them crosswiring (port 1 to port 2
maybe, but not 1 to 20) because the short cables won't reach.

But *users* have plugged cables in backwards (despite being keyed)
or into the wrong locations.  E.g., you have 200 pairs of identical
connectors, who's to say the two desired ends find their way into
the correct connectors?  Maybe 1A gets connected to 2B instead of 1B.
If you rely on the cables only being long enough to make the "proper"
connections, then you likely have to increase the spacing between
connection points to ensure the "slack" that is necessary in any
connection doesn't allow for the selection of an incorrect destination.
Liz's suggestion of having a default INTERNAL connection has some
merit.  That handles the "normal" connections and ANY patch cords
would be exceptions.  But, I don't know how that it is practical
given design constraints.