Power-over-Ethernet Regulator 802.3af

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Nivin37
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Power-over-Ethernet Regulator 802.3af

Post by Nivin37 » Mon Mar 19, 2012 5:27 am

Hi,

What is the minimum voltage the Power-over-Ethernet Regulator 802.3af will work with reliably.

I have a EtherTen going into a 24VDC Sola remote Radio installation, however it may end up as having 802.af 48VDC injected in the future.

SO I guess my real question is will the Power-over-Ethernet Regulator 802.3af work reliably at 24VDC & if so what is the lower limit for reliable supply.

Steve...

LukeW
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Re: Power-over-Ethernet Regulator 802.3af

Post by LukeW » Wed Mar 21, 2012 7:39 am

The 802.3af controller/enumerator chip in the Freetronics 802.3af module is likely to behave very strangely or not work at all if you feed it a voltage which is inconsistent with a standard 802.3af network. It will probably think that there's something wrong with the network because the voltage is too low.

If you're using "hacker style" PoE and not standard 802.3af power injection, you should use something like the Freetronics PR28V, which is just a "dumb" voltage regulator which does not expect standard 802.3af voltage levels and communication.

Because it uses a buck converter chip, it will be fine with high input voltages up to 28V, but it won't care exactly what that voltage is, as long as it's within 9-28V.

hometownfl
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Joined: Thu Oct 04, 2012 5:03 pm

Re: Power-over-Ethernet Regulator 802.3af

Post by hometownfl » Thu Oct 04, 2012 5:08 pm

A company called www.panoptictechnology.com has many different elegant solutions for POE issues. They have POE adapters that will scale down to any voltage you may need.

Manfred8651
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Re: Power-over-Ethernet Regulator 802.3af

Post by Manfred8651 » Thu Aug 14, 2014 4:22 pm

Hello!

(Sorry if my question is too stupid, I am a beginner.)

I want to use the "EtherTen" with PoE 802.3af.

1. Is it correct that the EtherTen support this, but not as it is, only with the additional module "Power-over-Ethernet Regulator 802.3af"? (Do I have to buy the "Power-over-Ethernet Regulator 802.3af" separately to use it with the EtherTen?)

2. Ist the product/module "Power-over-Ethernet Regulator 802.3af" like a Shield to put it on top of the board? Or ist it a connector/adapter between the ethernet/CAT5-cable and the EtherTen? Or is it a little chip which I have to put on a specific place into the EtherTen board?

Many thanks!
Manfred

angusgr
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Re: Power-over-Ethernet Regulator 802.3af

Post by angusgr » Thu Aug 14, 2014 10:10 pm

Hi Manfred,

Your question is definitely not stupid, please ask away!
Manfred8651 wrote: 1. Is it correct that the EtherTen support this, but not as it is, only with the additional module "Power-over-Ethernet Regulator 802.3af"? (Do I have to buy the "Power-over-Ethernet Regulator 802.3af" separately to use it with the EtherTen?)
Yes, if you want to power the EtherTen from an 802.3af port then you need the regulator module.
Manfred8651 wrote: 2. Ist the product/module "Power-over-Ethernet Regulator 802.3af" like a Shield to put it on top of the board? Or ist it a connector/adapter between the ethernet/CAT5-cable and the EtherTen? Or is it a little chip which I have to put on a specific place into the EtherTen board?
We don't actually have a proper QuickStart guide showing how to install the 802.3af module, sorry. I hadn't realised this, I'll try to get one up on the site.

In the meantime the similar "PR28V Regulator" Quick Start guide provides a good explanation of how a PoE regulator is installed onto the EtherTen:
http://www.freetronics.com/pages/pr28v- ... tart-guide

The "802.3af Regulator" module is the same size and shape as the PR28V. The only difference is the 802.3af is designed to work with proper standards-compliant (and higher voltage) 802.3af PoE ports, whereas the PR28V is for "homebrew" PoE at a lower voltage.

Please let me know if I can explain any of this in more detail.


Angus

Manfred8651
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Re: Power-over-Ethernet Regulator 802.3af

Post by Manfred8651 » Fri Aug 15, 2014 3:33 am

angusgr wrote:In the meantime the similar "PR28V Regulator" Quick Start guide provides a good explanation of how a PoE regulator is installed onto the EtherTen:
http://www.freetronics.com/pages/pr28v- ... tart-guide
Thank you! That helps!

On my wishlist would be a Ether/Ten/EtherMega/... with built-in "Regulator 802.3af". Are there any plans?

angusgr
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Re: Power-over-Ethernet Regulator 802.3af

Post by angusgr » Mon Aug 18, 2014 4:34 am

Thanks for the suggestion!

We don't have plans for that at the moment. The "modular PoE" feature means people can choose what regulation they need, whether they are doing 802.3af or "homebrew PoE" or neither. The 802.3af module won't work with the homebrew solutions, and both kinds are quite popular.

We will take it onboard though, especially if we come across a more flexible but still 802.3af-compliant power supply component.

OlaM
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Re: Power-over-Ethernet Regulator 802.3af

Post by OlaM » Mon Oct 06, 2014 8:09 am

I am sorry if this is answered elsewhere, but is it possible to mount a shield (like the short protoshield) on an EtherTen with a 802.3af-module installed?

In the installation guide for PR28V it says that you can either solder it directly or with a header, which will make it slightly higher. If a shield will work with the module directly soldered, will it work with the headers?

If I have installed the 802.3af-module, can I still use USB as PSU, or am I locked to PoE when I remove the jumpers?

I don't know which PS component is used in your 802.3af-module, but have you looked at AG9120S? Sparkfun use it in their 802.3af shield, and it looks like it is the same height as the RJ45 jack.

angusgr
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Re: Power-over-Ethernet Regulator 802.3af

Post by angusgr » Wed Oct 08, 2014 11:24 pm

Hi Ola,

With the 802.3af module installed, even when soldered rather than socketed the module sits higher than the shield pins (marginally higher than the RJ45 jack), so you can't install a shield directly.

However if you add a set of our stacking headers:
http://www.freetronics.com/products/sta ... ld-headers

They will give you more than enough clearance for any shield (including shields that would foul on the RJ45 jack, even without a PoE module in place.)

Thanks for the tip on the AG9120S. It does look like it could be a bit lower profile than the module we use now, but by the look of the photo it would still require extra headers to get enough clearance to stack a shield on top.


Angus

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