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ajmoreno
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RBFTC11: crossover cable to power from 802.3at POE (half-crossed or fully-crossed?)

Fri Mar 17, 2023 4:12 pm

Hello to all,

I have bought several units of RBFTC11, and they will be powered by gigabit 802.3at POE. According to documentation, one should use an "unshielded cross cable".

My question is about the wiring diagram of the crossover cable, i.e. either Half-crossed (two pairs crossed: 1,2, 3 and 6, two pairs uncrossed: 4, 5, 7 and 8, for 10BASE-T or 100BASE-TX crossover) or a Fully-crossed (all pairs crossed, the only crossover for 1G but also working for 10M and 100M ethernet).

Maybe anyone has experience in powering this device with gigabit POE 802.3at, and can share which wiring diagram is working.

According to the technical support, it might depend on the switch powering the RBFTC11, and even a straight cable might work. But I would prefer not to test too much with powering, and go to the assurance of experience. Given that it will work at gigabit speeds, I would assume that I should use a Fully-crossed diagram, but it is not clear and even technical support seems to suggest Half-crossed (usually for 100Mbps).

Thanks very much in advance,
AJ.
 
ajmoreno
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Re: RBFTC11: crossover cable to power from 802.3at POE (half-crossed or fully-crossed?)

Fri Apr 14, 2023 1:23 pm

Just for those who might be using this unit.

I have successfully powered the RBFTC11 with a straight cable (not even a crossover cable needed) with a 802.3at POE+ mode A (power in pins 1, 2, 3 and 6) switch.

Best,
AJ
 
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Re: RBFTC11: crossover cable to power from 802.3at POE (half-crossed or fully-crossed?)

Fri Apr 14, 2023 6:28 pm

I have bought several units of RBFTC11, and they will be powered by gigabit 802.3at POE. According to documentation, one should use an "unshielded cross cable".
But what did you understand?
We mean the ethernet cables that have the pairs twisted on themselves,
not the "cross cables" to connect two PCs to each other, which by the way now with the auto-detection in the chips there is no longer any need... ..
 
smigielski
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Re: RBFTC11: crossover cable to power from 802.3at POE (half-crossed or fully-crossed?)

Tue Apr 25, 2023 9:05 am

Can you tell me if RBFTC11 works with hAP ax² PoE. output port? Anything special needs to be done there?
 
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Re: RBFTC11: crossover cable to power from 802.3at POE (half-crossed or fully-crossed?)

Tue Apr 25, 2023 4:51 pm

It should.

Product page says PoE in range is 12-57V ... and seeing range of input voltage already means that device supports passive PoE in (802.3 af/at is always 48V give or take). Product brochure (available in Support&Downloads tab) agrees with my assessment.

hAP ax2 comes with 24V power adapter (which is fine with RBFTC11) and can output up to 0.6A via PoE out port (at 24V that translates to 14.4W which is much more than needed by RBFTC11).

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