Power over Ethernet 1

[DTSMAN]

I went to Richards web link and saw a sample of power over ethernet for wireless access points. You robbed two pairs for this. One, wouldn't this kill my link light and two, I thought power in or around ethernet lines was a no no.

 

[mikeydidit]

The power should be on the brown pair and should not affect your network connection. I don’t believe that the amount of power running across that pair is enough to give you any problems. This is the setup that we are using.

Mike Jones
LSUHSC

 

[franklin97355]

Also it's DC. That's how Cisco does it on their equipment.

 

[Jtodd]

Word of caution on Cisco's PoE, make sure you are using the 802.3 compliant version of Cisco's stuff. They've got their own version of PoE which only works with their stuff. Caused our network guys a bunch of headaches (and our vendor to send us different blades).

Once that was all worked out, we've got about 80 wireless access points on campus that are using PoE with any problems (as far as the PoE goes).

Justin T. Clausen
Physical Layer Implementation
California State University, Monterey Bay

 

[Servamatic]

Did you mean my web link on PoE?
I actually have a new product for PoE that will be introduced soon, currently testing the prototypes.
I will post on my site soon.
As to a link light, you actually only need 1 pair for a link light, but in 10/100 BaseT you only use 2 pairs for data transmission.
I use 2 pairs for PoE to reduce Voltage loss.
PoE won't work on 1000BaseT since you use ALL 4 pairs for gigabit.


Richard S. Anderson, RCDD

http://www.servamatic.net

 

[AdmanOK]

802.3af sends power over the same pairs that data is transmitted over (1+2 are negative, 3+6 are positive). It allows for devices to connect at 10BASE-T, 100BASE-TX and 1000BASE-T while receiving power. Check out the specification (

http://standards.ieee.org/getieee802/download/802.3af-2003.pdf)

for more information.