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Power-over-Ethernet: IEEE 802.3af Draft
SkewlD00d writes "Want power (~10W) and your fat 10/100Mbps pipe (1Gbps maybe) on the SAME jack. Surf the web and recharge your handheld w/o finding its clunky base/transformer, home automation, and control systems are just some of the possibilities. Using suitable hubs/switches or dongle, power can be provided over unused pairs, or possibly raise the signal offset above DC, X10-style (no link, u know why). See IEEE 802.3af DTE Power via MDI Task Force. Maxim (not that one :o) already has some goodies. They have schematics for 8.25W/12.5W single-output and 14.2W triple-output 802.3af PSU. Try FindChips if you're looking for them; they're in production and are NOT vapor-ware!"
Allows power to be distributed where there's no mains sockets (saves on wiring), but also has the potential to damage hardware if a short in the cable occurs.
OK this is a good idea from my perspective. I have used Cisco IP phones w9ith this and they work great it's a LOT easier than a UPS for every IP phone (look at a sales guy and try to explain why the phone died when they power took a hit phones need to be reliable) I have used it with 3com AP's again it works great and makes it easy to stick the AP on the drop ceiling and other hard to reach places PoE again can provided needed UPS power to the AP it also has the side benifit of the AP isn't up and running unless the network is plugged in (I have seen it happen it's not pretty)
I'm waiting for a laptop that can suplement/charge itself over PoE I have a subnotebook that only draws 14 watts charging PoE is close to that possibly enough for a trickle charge. It would seem to be a cheap addon to a laptop ethernet. A lot of people in offices hook laptops up to PSU but leave them on the wireless because it's easier this could make a one cable solution. I can see a whole line of terminals as well for POS applications. In reality on a lot of things this could replace the charger for small devices like PDA's and hook them up to the network at the same time.
Now it seems to be incompatable with GigE over copper since that uses all 8 wires.
No sir I dont like it.
While overstated, I wonder what the power safety capabilities are in some of the already-available implementations of this.
I'm not as worried about shock, but about unintentional shorts burning out switch ports or misplugged equipment. It'd be awesome if there were software-resettable breakers on the switches so that you wouldn't lose line cards. I had the misfortune of accidentally shorting a couple of Merlin phone system ports and those ports are dead, dead, dead forever.
I also wonder what it does to existing wiring codes and cable plants if any significant power starts to become present on data cabling. It'd suck to become dependent on this power only to have data cabling drops become more costly due to tighter code restrictions on where they can be placed.
Cisco uses unused pairs; hence, you can't have Gig-over-copper AND POE. Soon, soon...
You can purchase a power injector from several vendors who provide POE-capable devices -- good for, as you say, phones, and wireless access points.
I'd like to see a standard accepted for this, because as far as I know, the only products from the larger vendors (Cisco, Avaya) are propritary, so you can't use other POE-cabable devices from a different vendor on the same port.
The hot-swap chip is required by the standard and handles unitentional shorts. From the data sheet: "Provides Safe Hot Swap for +10V to +65V Power Supplies". This also 1) limits maximum inrush and 2) limits steady-stage current to 1) avoid "drooping" the supply voltage and 2) handle faults on the secondary (e.g. 6 V) side. I haven't looked at the standard recently, but there are supposed to be limits on the supply (-48 V) end to handle faults there. The reasons -48 V is used are it is very standard in telecom so low cost parts available for DC/DC converters and it is less than +/- 60 V which is the limit for "low voltage" in existing wiring codes.
or does the synopsis for this article look like it was written by some lame AOL script kiddie?
No I am not trolling, I think we should edit these synopsises before they go live.
X10 the protocol was developed by X10 the company, which still owns a number of patents on it.
So sadly, www.x10.com is the official site for the x10 protocol (although you can't find any details on the exact protocol these days.)
retrorocket.o not found, launch anyway?