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Patch-panel fabrication

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  Patch-panel fabrication Don Y <blockedofcourse@foo.invalid> - 2017-05-03 12:54 -0700
    Re: Patch-panel fabrication Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-05-03 13:23 -0700
      Re: Patch-panel fabrication Don Y <blockedofcourse@foo.invalid> - 2017-05-04 00:10 -0700
        Re: Patch-panel fabrication Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-05-04 11:27 -0700
          Re: Patch-panel fabrication Don Y <blockedofcourse@foo.invalid> - 2017-05-04 11:43 -0700
          Re: Patch-panel fabrication Clifford Heath <no.spam@please.net> - 2017-05-05 08:57 +1000
            Re: Patch-panel fabrication Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-05-06 05:47 -0700
          Re: Patch-panel fabrication krw@notreal.com - 2017-05-04 19:37 -0400
        Re: Patch-panel fabrication Neon John <no@never.com> - 2017-05-04 17:56 -0400
          Re: Patch-panel fabrication Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-05-06 05:46 -0700
        Re: Patch-panel fabrication Jasen Betts <jasen@xnet.co.nz> - 2017-05-11 05:57 +0000
          Re: Patch-panel fabrication Don Y <blockedofcourse@foo.invalid> - 2017-05-11 10:37 -0700
    Re: Patch-panel fabrication Martin Riddle <martin_ridd@verizon.net> - 2017-05-03 20:32 -0400
      Re: Patch-panel fabrication Don Y <blockedofcourse@foo.invalid> - 2017-05-03 23:59 -0700
    Re: Patch-panel fabrication Jasen Betts <jasen@xnet.co.nz> - 2017-05-04 06:34 +0000
      Re: Patch-panel fabrication Don Y <blockedofcourse@foo.invalid> - 2017-05-04 01:45 -0700
    Re: Patch-panel fabrication whit3rd <whit3rd@gmail.com> - 2017-05-04 01:52 -0700
      Re: Patch-panel fabrication Don Y <blockedofcourse@foo.invalid> - 2017-05-04 11:42 -0700
        Re: Patch-panel fabrication whit3rd <whit3rd@gmail.com> - 2017-05-04 21:22 -0700
          Re: Patch-panel fabrication Don Y <blockedofcourse@foo.invalid> - 2017-05-04 23:04 -0700
            Re: Patch-panel fabrication whit3rd <whit3rd@gmail.com> - 2017-05-04 23:24 -0700
              Re: Patch-panel fabrication Don Y <blockedofcourse@foo.invalid> - 2017-05-05 00:19 -0700
                Re: Patch-panel fabrication whit3rd <whit3rd@gmail.com> - 2017-05-05 00:45 -0700
                  Re: Patch-panel fabrication Don Y <blockedofcourse@foo.invalid> - 2017-05-05 02:17 -0700
    Re: Patch-panel fabrication jrwalliker@gmail.com - 2017-05-04 08:40 -0700
      Re: Patch-panel fabrication Don Y <blockedofcourse@foo.invalid> - 2017-05-04 10:12 -0700
        Re: Patch-panel fabrication jrwalliker@gmail.com - 2017-05-04 10:27 -0700
          Re: Patch-panel fabrication Don Y <blockedofcourse@foo.invalid> - 2017-05-04 11:01 -0700
            Re: Patch-panel fabrication makolber@yahoo.com - 2017-05-04 11:18 -0700
              Re: Patch-panel fabrication Don Y <blockedofcourse@foo.invalid> - 2017-05-04 11:27 -0700
        Re: Patch-panel fabrication Don Kuenz <g@crcomp.net> - 2017-05-06 05:33 +0000
          Re: Patch-panel fabrication Don Y <blockedofcourse@foo.invalid> - 2017-05-06 15:40 -0700
            Re: Patch-panel fabrication whit3rd <whit3rd@gmail.com> - 2017-05-06 20:15 -0700
              Re: Patch-panel fabrication Don Y <blockedofcourse@foo.invalid> - 2017-05-06 23:47 -0700
                Re: Patch-panel fabrication whit3rd <whit3rd@gmail.com> - 2017-05-07 03:51 -0700
                  Re: Patch-panel fabrication Don Y <blockedofcourse@foo.invalid> - 2017-05-07 05:20 -0700
            Re: Patch-panel fabrication (POE) Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2017-05-07 17:30 +0000
              Re: Patch-panel fabrication (POE) Don Y <blockedofcourse@foo.invalid> - 2017-05-07 11:49 -0700
                Re: Patch-panel fabrication (POE) Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2017-05-07 18:58 +0000
                  Re: Patch-panel fabrication (POE) Don Y <blockedofcourse@foo.invalid> - 2017-05-07 12:24 -0700
                    Re: Patch-panel fabrication (POE) Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2017-05-07 19:48 +0000
                      Re: Patch-panel fabrication (POE) Don Y <blockedofcourse@foo.invalid> - 2017-05-07 13:29 -0700
                        Re: Patch-panel fabrication (POE) Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2017-05-07 20:54 +0000
    Re: Patch-panel fabrication Allan Herriman <allanherriman@hotmail.com> - 2017-05-07 10:35 +0000
      Re: Patch-panel fabrication Don Y <blockedofcourse@foo.invalid> - 2017-05-07 05:26 -0700

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#458876

On Thursday, May 4, 2017 at 11:04:04 PM UTC-7, Don Y wrote:
> On 5/4/2017 9:22 PM, whit3rd wrote:
> > On Thursday, May 4, 2017 at 11:41:56 AM UTC-7, Don Y wrote:

> I have no idea how a string of 24 keystones in a 16" span would behave.

The point of using the keystones is FLEXIBILITY.   You can do something
significantly different than a string of 24.   Like, a strip 6' high, with a decorative
door that looks like the left side of a bookshelf, or a fluted column.

Trying to copy a wiring closet, is only gonna lead to something
that's just as imperfectly beautiful as a RETMA rack.  

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#458880

On 5/4/2017 11:24 PM, whit3rd wrote:
> On Thursday, May 4, 2017 at 11:04:04 PM UTC-7, Don Y wrote:
>> On 5/4/2017 9:22 PM, whit3rd wrote:
>>> On Thursday, May 4, 2017 at 11:41:56 AM UTC-7, Don Y wrote:
>
>> I have no idea how a string of 24 keystones in a 16" span would behave.
>
> The point of using the keystones is FLEXIBILITY.   You can do something
> significantly different than a string of 24.   Like, a strip 6' high, with a decorative
> door that looks like the left side of a bookshelf, or a fluted column.

But, I can do that pilfering parts from a COTS panel -- given that
I'm looking to make a "custom" front panel, it only stands to
reason that I can choose to put the individual connectors anywhere
I want!

E.g., space for a label above each connector is wasted -- I'd have to
lie on my belly to read what it written, there.  Likewise, numbers
printed *under* the connectors won't be visible with wires plugged
into the connectors immediately above!

What makes sense for a panel in a data center makes little sense
in a home -- unless you want to replicate the "data center experience"
(I don't!  :> )

I'm stuck with the amount of real estate capable of supporting a 4U panel.
But, it's split into to pieces.  So, 48 ports in each place.

But, within that "half 4U panel" space, I am free to arrange connectors
however I wish.  *If* I can come up with a way to mechanically support
them that is also cosmetically appealing.

The typical "black metal plate with white legend" is far too tacky/techy
for my tastes.  *But*, offers the right amount of rigidity, support, etc.

I need a way to make a functionally equivalent plate that has the
same mechanical characteristics to support that number of connectors.
The easiest approach, IMO, is to laser cut something.  Put the holes
wherever *I* want them, the legend where I want it, etc.

E.g., I think a more practical approach is to arrange the connectors
in columns (though they could be rotated 90 degrees within that
column).  This allows the VERTICAL column of empty space between
columns of connectors to be visible when looking DOWN, from above,
even when the connectors are mated to cables.  This space then being
suitable for "identification" (more later).

And, instead of ROWS of connectors, legend, connectors, legend...
being replaced by COLUMNS of connectors, legend, connectors, legend...
it would probably be more effective to use connectors, legend, legend,
connectors, connectors, legend...  This further "opens up" the
space (vertical column) for identifiers yet still lets the relationship
of identifier to connector be obvious -- why do they need to CONSISTENTLY
be above/below/left/right of their connectors?

Finally, numerical identifiers are just as difficult to "read" as
textual labels would be -- when the panel is hugging your ankles.
So, organize the connectors in a way that is more intuitive for
a user to commit to memory:  e.g., groups of 5 or 10 -- instead of
6 or 12 (common for COTS panels).

> Trying to copy a wiring closet, is only gonna lead to something
> that's just as imperfectly beautiful as a RETMA rack.

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#458884

On Friday, May 5, 2017 at 12:18:48 AM UTC-7, Don Y wrote:

> But, within that "half 4U panel" space, I am free to arrange connectors
> however I wish.  *If* I can come up with a way to mechanically support
> them that is also cosmetically appealing.

> I need a way to make a functionally equivalent plate that has the
> same mechanical characteristics to support that number of connectors.
> The easiest approach, IMO, is to laser cut something. 

That's what I don't get.   What kind of connector will attach
to a laser cut panel?   Will it include insulation displacement termination
of the wires from the depths of the wall? 

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#458892

On 5/5/2017 12:45 AM, whit3rd wrote:
> On Friday, May 5, 2017 at 12:18:48 AM UTC-7, Don Y wrote:
>
>> But, within that "half 4U panel" space, I am free to arrange connectors
>> however I wish.  *If* I can come up with a way to mechanically support
>> them that is also cosmetically appealing.
>
>> I need a way to make a functionally equivalent plate that has the
>> same mechanical characteristics to support that number of connectors.
>> The easiest approach, IMO, is to laser cut something.
>
> That's what I don't get.   What kind of connector will attach
> to a laser cut panel?   Will it include insulation displacement termination
> of the wires from the depths of the wall?

The connector doesn't attach to the panel.

(Currently) connector mounts on a circuit board along with the
punchdown block (foil traces on the PCB connect the punchdown
block to the connector pins).  Circuit board is fastened to
the front panel with threaded standoffs (screw heads are visible
countersunk in the outside surface of the panel).

(Again, currently) a custom printed (legended) mylar sheet
has holes cut in it for the rows of connectors to peek
through.

(Currently) panel supports 72 (36+36) connectors in rows
of 12 connectors that abut side-to-side.

New panel needs to support 96 (48+48) connectors.  The
easy (? straight-forward?) way to do so is to cannabilize
the "connector-punchdown PCB assemblies" from the old
panel (or, any number of similar panels that I've got
squirreled away).  Mount these to a new plate, laser cut
from acrylic, hardwood, etc.

But, acrylic/hardwood aren't stiff enough, by themselves,
to support someone pushing on such a panel to mate/demate
patch cords.  The plate ends up with so much material
removed to make space for the connector bodies that it
becomes flexible.  So, how to stiffen -- without moving to
something that makes it look like a typical patch panel
(e.g., black painted metal).

One solution is to just increase the thickness of the panel.
But, doing so for the *whole* panel (including the "mounting
ears") makes the panel protrude from the wall surface -- onto
which it fastens.  I.e., imagine a panel made out of "metal"
that was 1/2" thick!

[The connector bodies have a lot of depth, front to rear, so
the PCB sits well behind the panel, supported by standoffs.
This space can be filled with "thicker panel" and still keep
the front of the connector body flush with the outer surface
of the panel without the PCB touching the back side of the
panel!]

So, cut the "reinforcing panel" narrower & shorter so the front
panel piece overhangs it.  The smaller reinforced piece then
can fit *into* the hole in the wall while the actual front
panel sits ON the wall surface.  Standoffs that hold the PCBs
to the panel can be anchored into the panel *or* the
reinforcement behind it (which would keep the mounting screws
blind).  Front panel and reinforcement panel become one piece
(glue/screw/etc)

If the reinforcement layer was metal, it could provide the
stiffness of the current metal panel, with the wood/acrylic
laser cut panel acting like a veneer -- in much the same way
that the mylar legend sheet acts, currently.

But, its much easier to just laser cut another sheet of acrylic
(or wood) to serve this reinforcement role -- just run another
sheet through the laser cutter after changing the outer
dimensions a bit!  E.g., use a piece of hickory (for the outer
layer) and it will "match" the rest of the woodwork.  Or, a
piece of white acrylic and it will match the wall plates for
the electric outlets nearby.

There may be value in depopulating those PCB's (rather than trying
to find a source of soldertail punchdown blocks, etc.) and moving
those "components" to new PCBs laid out to better suit my needs.
E.g., I'd like to associate an indicator with each connector to
provide a convenient way of illustrating the performance/function
of each "port" (the switch isn't immediately visible and its
stock indicators don't indicate the same sorts of things that I'd
want to convey!)

But, silly to go too far down that road until I know how much flexibility
I have in configuring the panel, mechanically.

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#458723

On Wednesday, 3 May 2017 20:54:30 UTC+1, Don Y  wrote:

> The "easy" way of making something "cleanly/precisely cut" would
> be to do so on the laser cutter.  But, that limits you to
> acrylic and thin sheets of hardwood (60W CO2).  Neither of which
> is particularly stiff when those sorts of long slotted openings
> are introduced.

Not necessarily.  I recently had a large plate of 10mm thick steel
laser cut to modify a chimney for a woodburning stove.

John
 

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#458743

On 5/4/2017 8:40 AM, jrwalliker@gmail.com wrote:
> On Wednesday, 3 May 2017 20:54:30 UTC+1, Don Y  wrote:
>
>> The "easy" way of making something "cleanly/precisely cut" would
>> be to do so on the laser cutter.  But, that limits you to
>> acrylic and thin sheets of hardwood (60W CO2).  Neither of which
>> is particularly stiff when those sorts of long slotted openings
>> are introduced.
>
> Not necessarily.  I recently had a large plate of 10mm thick steel
> laser cut to modify a chimney for a woodburning stove.

With a "60W CO2" laser?  :>

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#458749

On Thursday, 4 May 2017 18:12:22 UTC+1, Don Y  wrote:
> On 5/4/2017 8:40 AM, jrwalliker@gmail.com wrote:
> > On Wednesday, 3 May 2017 20:54:30 UTC+1, Don Y  wrote:
> >
> >> The "easy" way of making something "cleanly/precisely cut" would
> >> be to do so on the laser cutter.  But, that limits you to
> >> acrylic and thin sheets of hardwood (60W CO2).  Neither of which
> >> is particularly stiff when those sorts of long slotted openings
> >> are introduced.
> >
> > Not necessarily.  I recently had a large plate of 10mm thick steel
> > laser cut to modify a chimney for a woodburning stove.
> 
> With a "60W CO2" laser?  :>

Perhaps a little bigger.

John

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#458760

On 5/4/2017 10:27 AM, jrwalliker@gmail.com wrote:
> On Thursday, 4 May 2017 18:12:22 UTC+1, Don Y  wrote:
>> On 5/4/2017 8:40 AM, jrwalliker@gmail.com wrote:
>>> On Wednesday, 3 May 2017 20:54:30 UTC+1, Don Y  wrote:
>>>
>>>> The "easy" way of making something "cleanly/precisely cut" would
>>>> be to do so on the laser cutter.  But, that limits you to
>>>> acrylic and thin sheets of hardwood (60W CO2).  Neither of which
>>>> is particularly stiff when those sorts of long slotted openings
>>>> are introduced.
>>>
>>> Not necessarily.  I recently had a large plate of 10mm thick steel
>>> laser cut to modify a chimney for a woodburning stove.
>>
>> With a "60W CO2" laser?  :>
>
> Perhaps a little bigger.

      "Do you expect me to talk?"
      "No, Mr Bond; I expect you to die!"

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#458762

Are we talking about Ethernet cables?

m

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#458764

On 5/4/2017 11:18 AM, makolber@yahoo.com wrote:
> Are we talking about Ethernet cables?

Female 8P8C ("RJ45") connectors.  In the OP, they are, in fact, mated
to "ethernet cables" (patch cords).  But, I will be using a similar
approach (and similar connectors) elsewhere in which "ethernet" isn't
involved.

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#459045

Don Y <blockedofcourse@foo.invalid> wrote:
> On 5/4/2017 8:40 AM, jrwalliker@gmail.com wrote:
>> On Wednesday, 3 May 2017 20:54:30 UTC+1, Don Y  wrote:
>>
>>> The "easy" way of making something "cleanly/precisely cut" would
>>> be to do so on the laser cutter.  But, that limits you to
>>> acrylic and thin sheets of hardwood (60W CO2).  Neither of which
>>> is particularly stiff when those sorts of long slotted openings
>>> are introduced.
>>
>> Not necessarily.  I recently had a large plate of 10mm thick steel
>> laser cut to modify a chimney for a woodburning stove.
>
> With a "60W CO2" laser?  :>
>

A Greenlee keystone knockout punch ought to also work. If such a thing
actually existed.

The ICC IC107PP024 24-port 2 RMS patch panel blank is only 1.5mm thick
?steel? The smallest Greenlee rectangular knockout punch measures
11.1mm x 22.2mm and is rated for a maximum thickness of 1.5mm. The
thickness rating goes up from that size.

A keystone knockout measures 15mm x 19mm. The top half of page 95 of the
Greenlee knockout catalog 

https://greenlee-cdn.ebizcdn.com/media/2015%20Knockouts.pdf

shows rectangular knockouts while the bottom half shows D-Sub knockouts.
We live in a keystone world. It's hard to believe that Greenlee doesn't
offer a keystone knockout.

Thank you,

--
Don Kuenz KB7RPU

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#459147

On 5/5/2017 10:33 PM, Don Kuenz wrote:
> Don Y <blockedofcourse@foo.invalid> wrote:
>> On 5/4/2017 8:40 AM, jrwalliker@gmail.com wrote:
>>> On Wednesday, 3 May 2017 20:54:30 UTC+1, Don Y  wrote:
>>>
>>>> The "easy" way of making something "cleanly/precisely cut" would
>>>> be to do so on the laser cutter.  But, that limits you to
>>>> acrylic and thin sheets of hardwood (60W CO2).  Neither of which
>>>> is particularly stiff when those sorts of long slotted openings
>>>> are introduced.
>>>
>>> Not necessarily.  I recently had a large plate of 10mm thick steel
>>> laser cut to modify a chimney for a woodburning stove.
>>
>> With a "60W CO2" laser?  :>
>
> A Greenlee keystone knockout punch ought to also work. If such a thing
> actually existed.
>
> The ICC IC107PP024 24-port 2 RMS patch panel blank is only 1.5mm thick
> ?steel? The smallest Greenlee rectangular knockout punch measures
> 11.1mm x 22.2mm and is rated for a maximum thickness of 1.5mm. The
> thickness rating goes up from that size.
>
> A keystone knockout measures 15mm x 19mm. The top half of page 95 of the
> Greenlee knockout catalog
>
> https://greenlee-cdn.ebizcdn.com/media/2015%20Knockouts.pdf
>
> shows rectangular knockouts while the bottom half shows D-Sub knockouts.
> We live in a keystone world. It's hard to believe that Greenlee doesn't
> offer a keystone knockout.

The problem isn't finding a way to cut a hole in a piece of material.
Rather, it has to do with getting *enough* "hole" in a piece of material
to accommodate the number of connectors that must poke through that
material and still have the material (panel) be mechanically strong enough
to support the connectors and the pressure exerted on them as cables
are mated/demated.

<https://touchtechblogdotcom.files.wordpress.com/2014/03/patch-panel-front-back-e1396203976842.jpg> 
shows 48 connectors.

And, the "area" that I have available for those 48 connectors!  (In my
specific case, the panel is twice as high and half as wide)  Note how
they are packaged in groups of 6 (in this case -- I've also seen groups of
4, 8 and 12).  This allows for the space on either side of each INDIVIDUAL
connector to be minimized -- effectively zero within a group of 6!

Each 6-port assembly is soldered to a small PCB (visible in the bottom
view of the panel) that splays the individual connector pins out to
punchdown blocks for IDC cable termination.  As such, there are only
8 "holes" in this particular panel (discounting the mounting holes
at the periphery) and each "hole" is actually a long *slot* through
which 6 connector bodies can protrude.

Look, again, at the front view of the panel.  Imagine those were 48 individual
keystone connectors.  How would you arrange them on the panel as a set
of *48* individual connectors?  48 individually punched holes?

Ignore the fact that they need to be labeled/legended.  Just consider making
accessible so you can slip your fingers between the 47 other cables to
mate or demate a particular cable of interest.  Choose the keystone jacks
with an eye towards how they impact the connections on the back side
(e.g., I have some in my "junk box" that present the 8 connections
as a continuous row of IDC points -- this makes the rear of the connector
much wider than the front.  I have others that arrange the connections
as two parallel columns traveling in the Z axis -- so the back ends up
roughly as narrow as the front but much deeper than the previous example)

Once you've made swiss cheese of the hypothetical panel, consider what you
will fabricate it with and how rigid it will be, when done.  Finally, consider
what it will look like (this isn't a data center!)

In my case, I have several different panels available to choose from.
But, all are rack format.  So, all are too wide.  E.g., the likeliest
candidates are 4 rows of 24 connectors (where each row of 24 can be
achieved with groups of 4, 6, 8 or 12 connectors)

<http://www.rackmountsolutions.net/images/300-patch-panel-Enlarged.jpg>
<https://d1tqc0m69rhker.cloudfront.net/products/sw-4854/sw-4854.jpg>
<http://www.rackmountsolutions.net/images/UP24_CAT6_LED.jpg>
<https://www.picclickimg.com/d/l400/pict/222269895149_/Cat6-Patch-Panel-96-Port.jpg>

Here's an alternative approach:
<http://i.ebayimg.com/images/g/TwQAAOSwWTRWunJd/s-l300.jpg>

[Note that the orgainzation *behind* the panel need not reflect the
organization as viewed from the front!  E.g., one of my panels
has four rows of connectors arranged in two groups of 12 -- but
these reside on four circuit boards, 24 per board]

So, the first hack is to cut along the middle to yield two mirror image
panels of 48 connectors, each.  Then, remove the mounting ears on the
left (right) side of each as they're useless without a counterpart on the
right (left) side.  Or, figure out how to augment each to gain that
extra mounting surface...

[Note that I'm not advocating actually *doing* this but, rather,
suggesting a means by which you could imagine the equivalent layout
in a suitable bit of real estate.]

I've drawn up a solution that might work -- by abandoning the
assumptions that are inherent in a rack-mounted configuration.
But, its hard to visualize whether you've enough space to get
fingers in to release the catches on the patch cables.  Or,
if you can easily identify the cable of interest, etc.

I'll see if I can cut it, tonight, and use it to mock up a real
panel with real connectors, cables, etc.  How accessible they
are.  How rigid the panel (I'll start with a heavy sheet of acrylic).
But, I've got some other obligations tonight that will be
competing for that time...  :<

What I've learned from this effort is that a *wired* solution
for a system of any physical size/complexity/interconnectivity
poses significant logistical challenges that have a big impact
on deployment strategy!  If you've got a basement, spare closet
in your media center, etc. then the problems are simplified.

Likewise, if you plan for this when designing/building the home
instead of trying to retrofit to an existing building!

But, the easy problems are hardly worth the time to solve!  :>

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#459174

On Saturday, May 6, 2017 at 3:40:13 PM UTC-7, Don Y wrote:
> On 5/5/2017 10:33 PM, Don Kuenz wrote:

> > We live in a keystone world. It's hard to believe that Greenlee doesn't
> > offer a keystone knockout.
> 
> The problem isn't finding a way to cut a hole in a piece of material.
> Rather, it has to do with getting *enough* "hole" in a piece of material

> Look, again, at the front view of the panel.  Imagine those were 48 individual
> keystone connectors.  How would you arrange them on the panel as a set
> of *48* individual connectors?  48 individually punched holes?

One way would be a Keystone x6 wallplate with blank area to the right holding labels for the
six ports, alternating downward with a blank area to the left holding labels for a
wallplate on the right.  Eight such  wallplate=sized items would take up about
40 vertical inches; intersperse with mount points for some switches/routers
and put an AC power strip on the bottom.   It'll all hide behind a 10" wide set of
tiles or a sculpted plaster column... or a mirror..

The 48-position rackmount item is not as easy to hide or decorate.
Using the parts from that rackmount is only easy if you rivet some studs into
the metal of your faceplate to act as circuitboard  mountpoints (and have
a convenient way to get to the back to affix the wires).

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#459183

On 5/6/2017 8:15 PM, whit3rd wrote:
> On Saturday, May 6, 2017 at 3:40:13 PM UTC-7, Don Y wrote:
>> On 5/5/2017 10:33 PM, Don Kuenz wrote:
>
>>> We live in a keystone world. It's hard to believe that Greenlee doesn't
>>> offer a keystone knockout.
>>
>> The problem isn't finding a way to cut a hole in a piece of material.
>> Rather, it has to do with getting *enough* "hole" in a piece of material
>
>> Look, again, at the front view of the panel.  Imagine those were 48 individual
>> keystone connectors.  How would you arrange them on the panel as a set
>> of *48* individual connectors?  48 individually punched holes?
>
> One way would be a Keystone x6 wallplate with blank area to the right holding labels for the
> six ports, alternating downward with a blank area to the left holding labels for a
> wallplate on the right.  Eight such  wallplate=sized items would take up about
> 40 vertical inches; intersperse with mount points for some switches/routers
> and put an AC power strip on the bottom.   It'll all hide behind a 10" wide set of
> tiles or a sculpted plaster column... or a mirror..

You misunderstand; I don't have an arbitrary space to play with.
Remember, the cables from the panel have to connect *to* something!
In my case, the *switch*.

I have a space (actually, two spaces) that are the size and shape of
half of a 96 position rack mount patch panel (which is why I used
*photos* of such things as examples of the space, so you could get
an idea as to the connector density -- the amount of "hole" removed
from any fabricated panel).

Look at the problem from the top.  Let's use *your* house, for
example (as you are infinitely more familiar with its layout).

[No basement or attic allowed, though (cuz we don't have either, here).
And, garage is similarly off-limits unless you want to air-condition it
(and hope nothing crawls inside the kit or the wiring spaces made
accessible as a result of its presence).]

First, you need to find a location for a 96 port *switch*.
Silly to worry about where to terminate the patch panel if
the switch to which it tethers isn't within a convenient
span!

Of course, you'll need to have power nearby for the switch
to operate.  As the rest of the distributed kit is powered
from the switch (PoE), the switch must be capable of sourcing
all of that power -- 1400W in my case.  So, you can't just
pick any old branch circuit and HOPE it has that much
*surplus* capacity (a 15A circuit derated to 80% leaves you
with 1440W capacity).

[We'll forget about the backup power supply, for now, as it
could potentially be located elsewhere -- as long as the
branch circuit that feeds the switch is ensured to be "up"]

Then, you have to ensure the heat thrown off by the switch has
a place to go.  And, that any active cooling won't be a nuisance
to the occupants of the residence (*you* wouldn't want to be
listening to fans running 24/7/365, right?).

And, you have to make it not be obtrusive.  You don't want to
have to look at the thing and explain it to your friends,
neighbors, houseguests etc.  (tough enough having to explain
why there's a pinball machine in the front hallway).

Finally, it has to be marginally accessible; you don't
want to have to move the refrigerator to gain access to it
lurking behind!  It would be nice if you could notice
"out of the corner of your eye" that something was remiss
(e.g., why is that FAULT indicator flashing?)

Have you found that place in YOUR home, yet?  :>

Here, the floorplan is very open.  No places to stash things
besides the *few* closets, pantry, etc.  The only "utility"
rooms are the laundry and the "furnace room".  Neither has
a place for a big switch without removing some existing item
(we need the HVAC and I'm not keen on commuting to the
laundromat weekly!)

[For example, the office kit is wired to a 24 port switch
fastened to the *underside* of one of the work surfaces -- as
are all of the network cables feeding that switch!]

So, that leaves "living space".  The idea of putting a rack -- even
something just big enough for switch plus panel -- in any of the
living-, dining-, family-, kitchen-, bed- or bath -rooms ain't
gonna fly.  Even if I put a big *plant* on it and claimed it
was a modernist PLANTER ("Why does your planter make that noise?")
or, cover it with a glass top and claim its a coffee table!!

Closets/pantries don't tend to have power -- but, you could
always *add* a branch circuit without that looking too odd
(this also gets around the concern for how lightly/heavily
loaded any OTHER branch circuit might be!)

But, if you don't want to *dedicate* the closet/pantry to an
"equipment closet" (cuz we have so LITTLE/FEW "hiding places"
in the floor plan), then you have to figure out how to
share the space with the things that have already laid claim
to the space!

You'd NOT want to surrender the *choice* spots in that
storage space to this kit as it rarely needs to be
accessed -- as long as you can get to it when you
NEED to and have some way of verifying its approximate
functionality without interacting with a "system console".

So, you pick the most out-of-the-way parts of the space
and use those.  E.g., UNDER the lowermost shelf as
most folks don't like bending down that far to extract
something from storage (we typically keep things like
bulk supplies down that low -- things that we can shove
in with a foot or *drag* back out; those could easily be
moved up a shelf to free that space -- with only moderate
grumbling from SWMBO)

But, remember, you need space for the switch *and* the
patch panel.  If you stack them vertically, then you
risk eating up TWO shelves.  OTOH, if you effectively
place one in front of the other, then they consume no
more vertical height than either, individually!  (this
assumes you don't have space to put them side-by-side;
*two* rack widths)

A bit of thought makes it obvious that literally stacking
one in front of the other won't work.  But, you can
put them at right angles to each other, shifting
the bulkiest component(s) -- i.e., the switch, UPS,
etc. -- BACK a bit to make room on the side(s) for
a patch panel.  And, with TWO sides available, you
can split the panel so its height (or depth/width) can
be halved.

+-------PPPPP-
|
| SSSS
| SSSS
| SSSS
| SSSS
| SSSS
|
+-------PPPPP-

This has the added benefit of allowing the wires to
connect to the rear of the panel through the natural
cavity in the wall (taking precautions with firestops
and fire-retardent caulk on the penetrations thereof).

This keeps all the patch cords in one dense area
instead of spread out vertically or horizontally
(or both).  So, all connections to the panel(s)
are accessible.  And, lets the entire front of the
switch remain accessible (if the space is a bit wider
than the switch itself to allow the cables to dress
to the left and right of it)

> The 48-position rackmount item is not as easy to hide or decorate.
> Using the parts from that rackmount is only easy if you rivet some studs into
> the metal of your faceplate to act as circuitboard  mountpoints (and have
> a convenient way to get to the back to affix the wires).

The back is accessed by removing the panel from its
attachment to the wall -- just like it would be
accessed in a rack (you wouldn't try to reach THROUGH
a rack to access the rear-side of the individual
connectors).

The little circuit boards mount to the panel face in the same way
that they do to a COTS metal face:  with long screws through
unthreaded standoffs (spacers).  In effect, "studs".

For a front panel that has been reinforced by adding a stiffening
layer behind the visible face, the screw heads can protrude through
the back reinforcing layer, countersunk.  The visible front layer
can be adhered to the reinforcing layer rendering the screw
heads invisible (and inaccessible).  To keep a screw captive, a
nut threaded onto each screw on the rear surface of the reinforcing
panel ensures that the screw never loosens -- much like a stud is
never expected to loosen from a panel from which it has been
"extruded".  (remember, there's space behind the panel before you
reach the circuit boards)

I.e., layout front panel so it is cosmetically arranged as you'd like.
Trim ~3/8" from all edges of that panel and shoot another copy of
the same hole pattern -- with the holes for the "studs" added.  Insert
screws ("studs") into this smaller reinforcing panel and fasten with
nuts.  Align front panel to rear panel (using cutouts for connectors)
and adhere.  Thread standoffs -- shortened by the thickness of the
reinforcing panel -- onto the captive screws.  Follow with the
PCB's and a final locknut to hold captive.

No visible hardware on the front panel.  Wiring side remains
accessible (by removing panel from wall mount).  Defective
connectors (inevitable, over time) replaced by removing the
afflicted PCB and replacing with repaired unit -- snipping
the "used" portion of the 4/6/8/12 network cables off each
and reconnecting to the punchdown blocks.

Panel can now be a piece of tacky techy sheet metal, acrylic,
hardwood, etc.  Reinforcement layer can differ in composition
from the visible layer.

Sell home?  Remove custom switch and 1U slide-out console.  Replace
with a smaller, more vanilla, "green" switch.  Pitch it as a
*feature* to prospective homeowners:
    "The house is completely wired and here's a convenient,
     out-of-the-way place for you to locate your network printer,
     ISP modem, wireless router, media tank, etc. -- and, without
     significantly impacting the generic storage space available!
     You could even get in the habit of placing your portable
     devices on a shelf in here to be recharged -- there's an
     electric outlet right over there for their wall wart chargers!"

[I'm hoping to finagle another shelf, there, and move one of
the low volume printers and a few other small bits of kit
(like some of the NAS's) into there, as well, to get them out
of the office]

Repeat the exercise for the other "systems" in the house
and you quickly discover there's more effort involved
trying to terminate wires and *hide* things than you could
ever imagine!  :-/

I had hoped to fab a sample panel, tonight.  But, ran late and
had to defer to other obligations.  *But*, my buddy offered
to cut it for me (without me having to hang around):  "Let
me see what *I* can do..."  Hopefully, I'll get back over there
tomorrow to pick it up and run some "empirical tests".

(I imagine there are ways to *design* things with suitable
mechanical and anthropomorphic characteristics but I have
to rely on instinct and physical mock-ups:  cables are too
close together; panel flexes too much; etc.)

[I'd genuinely be interested in how you'd accommodate something like
this in your existing home as I'll be needing ideas to suggest to
others who want to travel the same road -- WITHOUT having to
"build a custom home"!]

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#459201

On Saturday, May 6, 2017 at 11:47:22 PM UTC-7, Don Y wrote:

> Look at the problem from the top.  Let's use *your* house, for
> example (as you are infinitely more familiar with its layout).
> 
> [No basement or attic allowed, though (cuz we don't have either, here).

> First, you need to find a location for a 96 port *switch*.

Not quite right; my house doesn't have 96 outlets all wired to 
a central location, it'll NEVER have or need more than a dozen or two
active.   Extra wire runs before you need it is a good thing.  But, 8 dozen?
If the audio/video cluster needs a few ports for TV/vidgame/streaming-audio,
it'll get its own eight-port switch and ONE cat5 to the closet.  Or MAYBE
two.   

> Of course, you'll need to have power nearby for the switch
> to operate.  As the rest of the distributed kit is powered
> from the switch (PoE), the switch must be capable of sourcing
> all of that power -- 1400W in my case

My only PoE switch is eight ports; even with full PoE load, it
can't use more than 60w.   It seems your problem definition 
has an order of magnitude larger scale than mine, but the
'available places' has smaller scale.   I've got a unfinished basement
available.

> And, you have to make it not be obtrusive. (tough enough having to explain
> why there's a pinball machine in the front hallway).

Yeah, I had the Galaga machine in the front hallway for a while.
Got rid of it.

> Finally, it has to be marginally accessible
> Have you found that place in YOUR home, yet?  :>

Not an ideal place, no.   Two closets that have adjacent
boxed-in but unused volumes, where a part of the wall could
be opened (steel 'inspection door' insert and some paint, and it'll
look like it belongs).  One large closet, where there's a 1' by 5' 
over-the-door space where one could fit a shallow shelf or RETMA rack.
And, the basement.


> [For example, the office kit is wired to a 24 port switch
> fastened to the *underside* of one of the work surfaces -- as
> are all of the network cables feeding that switch!]

Yeah, I had a desk once that included an office telephone switchboard
(the kneehole of the desk included a latched panel over a relay rack).
That's an OK solution, and your office now needs far less support
from the central network panel; maybe instead of 96 ports, down
to 72?

> So, you pick the most out-of-the-way parts of the space
> and use those....

But, that doesn't always work.  Sometimes, you have to evict an
old tenant.   Pinball machine?

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#459205

On 5/7/2017 3:51 AM, whit3rd wrote:
> On Saturday, May 6, 2017 at 11:47:22 PM UTC-7, Don Y wrote:
>
>> Look at the problem from the top.  Let's use *your* house, for
>> example (as you are infinitely more familiar with its layout).
>>
>> [No basement or attic allowed, though (cuz we don't have either, here).
>
>> First, you need to find a location for a 96 port *switch*.
>
> Not quite right; my house doesn't have 96 outlets all wired to
> a central location, it'll NEVER have or need more than a dozen or two
> active.   Extra wire runs before you need it is a good thing.  But, 8 dozen?

They aren't "extra".

72 of the drops are connected to bits of "automation" stuffed in walls,
ceilings, etc.  E.g, 11 "IP cameras", irrigation system controller,
10 "network speakers", HVAC controller, alarm system, rooftop weather
station, skylight controllers, utility monitoring, tie in to genset,
controller for laundry, garage door, 3 "control panels" to interact
with the system, etc. etc.

The remaining 24 drops are what you'd tend to think of as a "wired home";
uncommitted "outlets" scattered around the house.  Places where you might
want to plug in a laptop, printer, etc.  The difference being that I can
provide some power to those locations without resorting on "local" wall
warts.

*Or*, a "media display" that can pull content from a "media tank", etc.
(e.g., one in each bedroom, living room, family room -- even kitchen,
if desired)

If I split up the switch, then I just end up having to solve the same
problem in multiple places -- including battery backup, physical
security, etc.

> If the audio/video cluster needs a few ports for TV/vidgame/streaming-audio,
> it'll get its own eight-port switch and ONE cat5 to the closet.  Or MAYBE
> two.

Goal is to replace the conventional appliances, here, with IP-everything.
E.g., there are OTA tuners to capture "broadcast media" and store to
media server; then "displays" (audio or video) to replay that content
at later times -- in any room that has an uncommitted drop (into which
a "display" can be fitted).

>> Of course, you'll need to have power nearby for the switch
>> to operate.  As the rest of the distributed kit is powered
>> from the switch (PoE), the switch must be capable of sourcing
>> all of that power -- 1400W in my case
>
> My only PoE switch is eight ports; even with full PoE load, it
> can't use more than 60w.

Most PoE switches are intended for use in VoIP systems.  So, 7.5W/phone
is adequate (8*7.5=60W!  :> )

OTOH, if you're powering a loudspeaker over that drop, 7.5W for the
remote "computer"/electronics *and* audio output power is a bit cramped.

Likewise, if powering solenoids for irrigation system, how many do you
want to be able to activate concurrently (note that you have to always
activate the master solenoid in addition to any zones slaved to it).

How much power for the Ir illuminators on the cameras?  Or for the PTZ
bases?

Etc.

[You might want to see what sort of money folks get for 96 port PoE
switches with 1+KW capabilities.  Then, figure out how much more to
battery backup the thing (being able to shed loads to conserve
battery)  :>  It's "enlightening"!  :< ]

> It seems your problem definition
> has an order of magnitude larger scale than mine, but the
> 'available places' has smaller scale.   I've got a unfinished basement
> available.

Yes, the missing basement is the real killer.  But, basements appear
to be few and far between in this part of the country (lots of stuff
hiding under beds that should be in a basement -- electronics don't like
being stored in overly hot garages!)

>> And, you have to make it not be obtrusive. (tough enough having to explain
>> why there's a pinball machine in the front hallway).
>
> Yeah, I had the Galaga machine in the front hallway for a while.
> Got rid of it.

I left a Tempest in Chicago cuz it was too damn heavy to get onto
the truck.  Neighbor's wife wasn't too happy with me (though the
neighbor was ecstatic!).  Left another pinball with a friend for
similar reasons.  And, one back in my childhood home.  <shrug>

The nature of the toys changes, with age...  but, the desire to play
doesn't!

>> Finally, it has to be marginally accessible
>> Have you found that place in YOUR home, yet?  :>
>
> Not an ideal place, no.   Two closets that have adjacent
> boxed-in but unused volumes, where a part of the wall could
> be opened (steel 'inspection door' insert and some paint, and it'll
> look like it belongs).  One large closet, where there's a 1' by 5'
> over-the-door space where one could fit a shallow shelf or RETMA rack.
> And, the basement.

Closets in each of the bedrooms.  But, those are supposed to be
*bedrooms*, not "equipment rooms".  Remember, you've still got all
those BTUs to deal with!

>> [For example, the office kit is wired to a 24 port switch
>> fastened to the *underside* of one of the work surfaces -- as
>> are all of the network cables feeding that switch!]
>
> Yeah, I had a desk once that included an office telephone switchboard
> (the kneehole of the desk included a latched panel over a relay rack).
> That's an OK solution, and your office now needs far less support
> from the central network panel; maybe instead of 96 ports, down
> to 72?

Note that I've not included the 24 ports (of which, only 20 are in use)
in the office nor the 7 in the spare bedroom.  Separate switches in
those locations handle those and connect to the rest of the house
through one of the two drops present in each bedroom (one of each is
intended to eventually feed a media display in each room while the
other could be used to talk to the outside world (e.g., a laptop;
eschew wireless!)

>> So, you pick the most out-of-the-way parts of the space
>> and use those....
>
> But, that doesn't always work.  Sometimes, you have to evict an
> old tenant.   Pinball machine?

In my case, I have to ensure SWMBO doesn't get too pissy about my
play things.  But, long term, have to make sure I don't bugger the house
in ways that make it difficult to resell.  E.g., exploiting one of the
walk-ins in the master bedroom might be convenient FOR ME -- but, could
be a turn off for a future owner wondering why there are all those
wires in the bedroom closet!  :<

[I've a friend whose husband passed away a few years ago.  She was
complaining to me about the wires in the bedroom closet.  I didn't
understand what she was referencing until I visited:  turns out her
husband had chosen a closet in one of the spare bedrooms to house
an assortment of "stuff" that he'd wired throughout the house.
Not even a consistent set of stuff -- just a random assortment of
wires for various purposes that he elected to terminate in that
closet.  "What should I do with all these things?"  "Tuck the
excess into the walls and have a drywall guy come over and plaster
it over.  Pretend it doesn't exist!"]

A big part of this has been learning what the problems would be
retrofitting a wired solution to an existing home.  Wireless
solutions are easier to deploy.  But, require lots of distributed
power sources (72 of them?) for the various bits of kit around
the house.

And, are easily subverted by anyone intent on disrupting comms
(e.g., to cripple the alarm system's ability to report an
intrusion).  Or, anyone intent on monitoring the activities
within the house, remotely ("Gee, let's listen in on what is
being said in the bedroom...")

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#459253 — Re: Patch-panel fabrication (POE)

On a sunny day (Sat, 6 May 2017 15:40:31 -0700) it happened Don Y
<blockedofcourse@foo.invalid> wrote in <oelj65$l44$1@dont-email.me>:

>What I've learned from this effort is that a *wired* solution
>for a system of any physical size/complexity/interconnectivity
>poses significant logistical challenges that have a big impact
>on deployment strategy!  If you've got a basement, spare closet
>in your media center, etc. then the problems are simplified.


Don, do I understand right you will be using POE?
There are some catches there too.
I ran into this:
The simple ebay ethernet modules with an ENC28J60 controller:
 http://www.ebay.com/itm/381447240602
  those use this connector:
   http://www.kosmodrom.com.ua/pdf/HR911105A.pdf

Note the 75 Ohm resistors between pin 7 and 8 (POE -) and pin 4 and 5 (POE +).

There is, it seems, lots of stuff around that has those connectors.

If you put 48 V on that, then it sees 150 Ohm, (48*48)/150 = 15.36 W generated in that connector.
So it could cause damage to somebodies stuff if they plug it in and has that connector or a similar one.
I am replacing all those connectors by HLJ6115ANL, also because it has 7,8 and 4,5 accessible and I need that to get the POE.
 http://www.ebay.com/itm/271891560407
But that is not something you can do with just any laptop... you plug in.

Also there seem to be more than a few POE standards:
 http://pinoutguide.com/Net/poe_pinout.shtml
 

 

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#459268 — Re: Patch-panel fabrication (POE)

On 5/7/2017 10:30 AM, Jan Panteltje wrote:
> On a sunny day (Sat, 6 May 2017 15:40:31 -0700) it happened Don Y
> <blockedofcourse@foo.invalid> wrote in <oelj65$l44$1@dont-email.me>:
>
>> What I've learned from this effort is that a *wired* solution
>> for a system of any physical size/complexity/interconnectivity
>> poses significant logistical challenges that have a big impact
>> on deployment strategy!  If you've got a basement, spare closet
>> in your media center, etc. then the problems are simplified.
>
> Don, do I understand right you will be using POE?

I'm using much of the PoE *technology* -- so that I can
leverage components made to address those needs.  But,
I've bastardized the "standard" to better suit my needs
(without compromising compatibility with COTS devices)
simply because my needs differ from "typical".

> There are some catches there too.
> I ran into this:
> The simple ebay ethernet modules with an ENC28J60 controller:
>  http://www.ebay.com/itm/381447240602
>   those use this connector:
>    http://www.kosmodrom.com.ua/pdf/HR911105A.pdf
>
> Note the 75 Ohm resistors between pin 7 and 8 (POE -) and pin 4 and 5 (POE +).

I'm using "dumb" connectors in the patch panel, of course (no magnetics
needed, there).  I'm avoiding "value added" components because they
usually come with "strings attached" -- mechanical configurations, sole
source, etc.

> There is, it seems, lots of stuff around that has those connectors.
>
> If you put 48 V on that, then it sees 150 Ohm, (48*48)/150 = 15.36 W generated in that connector.

<grin>  A simple way to "solve" the power negotiation phase of the
connection protocol:  just *use* everything that's theoretically available
regardless of the PD class!  A Class 1 device consumes as much power as
a class 3 -- and NEITHER end up with enough power to actually OPERATE!  :>

> So it could cause damage to somebodies stuff if they plug it in and has that connector or a similar one.
> I am replacing all those connectors by HLJ6115ANL, also because it has 7,8 and 4,5 accessible and I need that to get the POE.
>  http://www.ebay.com/itm/271891560407
> But that is not something you can do with just any laptop... you plug in.

Hmmm... are you suggesting the problem is OTHER devices that might get plugged
into my network?

> Also there seem to be more than a few POE standards:
>  http://pinoutguide.com/Net/poe_pinout.shtml

Yes, I support both type a and type b power configurations -- because I can't
know, for sure, what other PSE/PD kit I may encounter in the future.  And,
there have been several "bastardizations" along the way (I have some Cisco
AP's that aren't compliant)

I opted *not* to support PoE+ just because you have to draw the line
*somewhere* when it comes to centrally distributed power.  E.g., I suspect
when I design my "media (video) displays" -- in lieu of TV's -- I may find
the PoE supply inadequate.  But, I can tolerate a wall wart at that site as
there will obviously need to be AC mains available for the display *panel*.

<shrug>

My goal isn't perfection but, rather, a BIG step away from the more
traditional/naive way of powering distributed kit.  I suspect time
is on my side in that kit is always getting more capable and at lower
power levels.

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#459269 — Re: Patch-panel fabrication (POE)

On a sunny day (Sun, 7 May 2017 11:49:53 -0700) it happened Don Y
<blockedofcourse@foo.invalid> wrote in <oenq1n$kb3$1@dont-email.me>:

>> So it could cause damage to somebodies stuff if they plug it in and has that connector or a similar one.
>> I am replacing all those connectors by HLJ6115ANL, also because it has 7,8 and 4,5 accessible and I need that to get the POE.
>>  http://www.ebay.com/itm/271891560407
>> But that is not something you can do with just any laptop... you plug in.
>
>Hmmm... are you suggesting the problem is OTHER devices that might get plugged
>into my network?

Exactly.


>> Also there seem to be more than a few POE standards:
>>  http://pinoutguide.com/Net/poe_pinout.shtml
>
>Yes, I support both type a and type b power configurations -- because I can't
>know, for sure, what other PSE/PD kit I may encounter in the future.  And,
>there have been several "bastardizations" along the way (I have some Cisco
>AP's that aren't compliant)
>
>I opted *not* to support PoE+ just because you have to draw the line
>*somewhere* when it comes to centrally distributed power.  E.g., I suspect
>when I design my "media (video) displays" -- in lieu of TV's -- I may find
>the PoE supply inadequate.  But, I can tolerate a wall wart at that site as
>there will obviously need to be AC mains available for the display *panel*.
>
><shrug>
>
>My goal isn't perfection but, rather, a BIG step away from the more
>traditional/naive way of powering distributed kit.  I suspect time
>is on my side in that kit is always getting more capable and at lower
>power levels.

Yes, OK, I use these selectively to places where I am sure there is only my own equipment connected:
 http://www.ebay.com/itm/151643358383
with my own power supply of course.

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#459274 — Re: Patch-panel fabrication (POE)

On 5/7/2017 11:58 AM, Jan Panteltje wrote:
> On a sunny day (Sun, 7 May 2017 11:49:53 -0700) it happened Don Y
> <blockedofcourse@foo.invalid> wrote in <oenq1n$kb3$1@dont-email.me>:
>
>>> So it could cause damage to somebodies stuff if they plug it in and has that connector or a similar one.
>>> I am replacing all those connectors by HLJ6115ANL, also because it has 7,8 and 4,5 accessible and I need that to get the POE.
>>>  http://www.ebay.com/itm/271891560407
>>> But that is not something you can do with just any laptop... you plug in.
>>
>> Hmmm... are you suggesting the problem is OTHER devices that might get plugged
>> into my network?
>
> Exactly.

There's a hardware handshake that transpires between the PSE and a
potential PD.  The PSE looks for characteristic resistances on the signal
leads and, based on what it senses, determines what class of PD device
is being plugged.  If it senses a noncompliant device, it doesn't
apply power to the conductors.

This is how you prevent things like (analog!) telephones misplugged into PoE
jacks from wreaking havoc.

The trickier aspect is handling the case where the device remains
physically connected but you've elected to power the port down... then
up again.

>>> Also there seem to be more than a few POE standards:
>>>  http://pinoutguide.com/Net/poe_pinout.shtml
>>
>> Yes, I support both type a and type b power configurations -- because I can't
>> know, for sure, what other PSE/PD kit I may encounter in the future.  And,
>> there have been several "bastardizations" along the way (I have some Cisco
>> AP's that aren't compliant)
>>
>> I opted *not* to support PoE+ just because you have to draw the line
>> *somewhere* when it comes to centrally distributed power.  E.g., I suspect
>> when I design my "media (video) displays" -- in lieu of TV's -- I may find
>> the PoE supply inadequate.  But, I can tolerate a wall wart at that site as
>> there will obviously need to be AC mains available for the display *panel*.
>>
>> <shrug>
>>
>> My goal isn't perfection but, rather, a BIG step away from the more
>> traditional/naive way of powering distributed kit.  I suspect time
>> is on my side in that kit is always getting more capable and at lower
>> power levels.
>
> Yes, OK, I use these selectively to places where I am sure there is only my own equipment connected:
>  http://www.ebay.com/itm/151643358383
> with my own power supply of course.

Yes, Cisco has a little device that impresses 48V on the unused pairs
for their (older) AP's.  But, it's literally just an adapter from
48VDC wall wart "barrel connector" to midspan injector.  Plug one
of the devices you're worrying about, above, into it and it
will gladly deliver 48V @ 380mA to the "load".

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