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eejimm
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PoE pinout and specs

Given how much confusion there is here about AirFiber PoE and using other injectors, could someone from UBNT actually post the pinout and specifications for the AF radio? I realize that UBNT would probably rather everyone just used their AC powered PoE brick, but there are so many situations where that isn't the best solution that I think it's time to get the info direct from UBNT.

It would also let those with enough experience at this use or develop other PoE solutions to power these radios. I know I won't be using them ever with an AC powered PoE injector; everything we do now is DC direct from a battery plant.

So help us out, UBNT folks, and please let us know what we're dealing with here.

If you feel it's so proprietary that you don't want to publish it to everyone, someone please PM me and let's see what other avenue we might take. I sign NDAs all the time with some pretty big companies...
Jim
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alexjhart
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Re: PoE pinout and specs

Given how much confusion there is here about AirFiber PoE and using other injectors, could someone from UBNT actually post the pinout and specifications for the AF radio? I realize that UBNT would probably rather everyone just used their AC powered PoE brick, but there are so many situations where that isn't the best solution that I think it's time to get the info direct from UBNT.

It would also let those with enough experience at this use or develop other PoE solutions to power these radios. I know I won't be using them ever with an AC powered PoE injector; everything we do now is DC direct from a battery plant.

So help us out, UBNT folks, and please let us know what we're dealing with here.

If you feel it's so proprietary that you don't want to publish it to everyone, someone please PM me and let's see what other avenue we might take. I sign NDAs all the time with some pretty big companies...
Jim


I know they are using all the pairs for power, but I am not sure of the negative/positive pin out. Let us know if they go the PM route so others can do the same. I don't expect that to be the case though.
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WHT
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Re: PoE pinout and specs

As it's a GigaBit PoE, that's going to be tricky to DIY one together.
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Josh_SPITwSPOTS
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Re: PoE pinout and specs

As it's a GigaBit PoE, that's going to be tricky to DIY one together.

Ghetto way? Scotch locks and diodes + fuses :mantongue:
Really need at least a bread board to do it halfway right.
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Dave-D
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Re: PoE pinout and specs

No--no way to 'ghetto' this--at least
not the way you describe.

This requires center-tapped Ethernet
isolation transformers. Dave
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Re: PoE pinout and specs

No--no way to 'ghetto' this--at least
not the way you describe.

This requires center-tapped Ethernet
isolation transformers. Dave

Why is that? I'm no EE, fill me in.
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Re: PoE pinout and specs

Oh gee..where to begin.
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Re: PoE pinout and specs

Think how a phone line can use balanced twisted pair (where neither conductor is reference to ground) and still be powered by a battery that is referenced to ground (though it may be a positive return).
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Re: PoE pinout and specs

Wiki en.wikipedia.org/wiki/Power_over_ethernet
Standards-based power over Ethernet is implemented following the specifications in IEEE 802.3af-2003 (which was later incorporated as clause 33 into IEEE 802.3-2005) or the 2009 update, IEEE 802.3at. A phantom power technique is used to allow the powered pairs to also carry data. This permits its use not only with 10BASE-T and 100BASE-TX, which use only two of the four pairs in the cable, but also with 1000BASE-T (gigabit Ethernet), which uses all four pairs for data transmission. This is possible because all versions of Ethernet over twisted pair cable specify differential data transmission over each pair with transformer coupling; the DC supply and load connections can be made to the transformer center-taps at each end. Each pair thus operates in common mode as one side of the DC supply, so two pairs are required to complete the circuit. The polarity of the DC supply may be inverted by crossover cables; the powered device must operate with either pair: spare pairs 4–5 and 7–8 or data pairs 1–2 and 3–6. Polarity is required on data pairs, and ambiguously implemented for spare pairs, with the use of a diode bridge.
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Dave-D
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Re: PoE pinout and specs

Josh, the short answer is that every Ethernet
signal pair has a low-voltage data signal that is
coupled to the cable using a small transformer.
That isolates its 'ac' signals from any dc voltage
on the cable, that might disturb the signals or
blow out the sensitive data circuits.

That means you can't put a dc voltage between the
wires of a data pair. To add a PoE voltage, you have
to 'straddle' between two pairs [one +, one -), so the
dc is the same on both wires of a single pair. The
way to do that is with two center-tapped transformers.

Because Gigabit uses all four pairs that requires four of
these transformers on each end. Dave
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Re: PoE pinout and specs

Like this (but not quite)?
www.parts-express.com/pe/showdetl.cfm?partnumber=129-084
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Dave-D
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Re: PoE pinout and specs

Um, well, that is a center-tapped transformer.

Otherwise, it's a power transformer, not a signal
type, it lowers voltage rather than has the same
windings on both sides, it's 40x the size of the
signal transformers used, it's made of iron instead
of ferrite, it has wires instead of PCB mount.

Otherwise, a perfect match! Dave
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Re: PoE pinout and specs

As Dave pointed out, it's laminated strips of iron, signaling and swiching power supplies use ceramic ferrite material.
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eejimm
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Re: PoE pinout and specs

No PM reply from UBNT yet...
I'd really hate to have to wait 'till I get an AirFiber unit to reverse engineer, although I could buy an AF PoE injector when they become available stand-alone...
Jim

Edit - Maybe nobody's back from Las Vegas yet, and they're all otherwise occupied :icon_cool:
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MeWireless
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Re: PoE pinout and specs

Like this (but not quite)?
www.parts-express.com/pe/showdetl.cfm?partnumber=129-084


Like this actually

www.alliedcomponents.com/lan_pdf/AHSC-4802I.pdf
Draw a picture of exactly what you're wanting to do. There is either a language barrier here or you don't understand this equipment. I suspect its a bit of both


Any opinions expressed are my own, and generally unpopular with others.

All rights reserved - but some wrongs are still available.
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Re: PoE pinout and specs

No PM reply from UBNT yet...
I'd really hate to have to wait 'till I get an AirFiber unit to reverse engineer, although I could buy an AF PoE injector when they become available stand-alone...
Jim
Edit - Maybe nobody's back from Las Vegas yet, and they're all otherwise occupied :icon_cool:

Everybody is still at WISPA I believe. And/or hungover.
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eejimm
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Re: PoE pinout and specs

Got the answer from another post - see the picture in #14
+50V on 1,2 and 4,5, negative on 3,6 and 7,8.
forum.ubnt.com/showthread.php?t=61533&page=2
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Re: PoE pinout and specs

'mewireless', sorta more like that, but not
quite either. That 'chip' has transformers
only rated to 100Mbps, and only 700mA.

It can't support Gb and 1A or more. Dave
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Dave-D
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Re: PoE pinout and specs

Not quite right with the pair numbering. Dave
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eejimm
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Re: PoE pinout and specs

Here is exactly what it will take...
productfinder.pulseeng.com/product/H6096NL

DaveD - thanks for noticing, I fixed the pinout...
Jim
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