Power over Ethernet

[tbeestoni 0]

can anyone please explain this 2 me. does the power travel without connections (in thin air) and is this possible? or have i got it all wrong and connections do have to be made all the way from one device to another, i only use my cameras for my own home security via plug and play cables and the only ethernet connection i have is from my dvr to pc. Can i use this POE with my system or is it mainly for ip cameras

 

Thanks

[sviviani 0]

poe stands for power over ethernet. there you would need a poe switch or injector to use it, it does not go "over the air". and it would not be needed with analog cameras. hope this helps

[Soundy 1]

Yes, Power over Ethernet in this instance would be used specifically for IP cameras. 10/100 ethernet uses only two of the four pairs of wire in an ethernet cable, so in its simplest form*, a PoE injector or PoE-capable switch would provide power over the two unused pairs to any receiving device that supports it (typically, cameras, access points, VoIP phones, etc.)

 

In short: it still requires a wired connection, all it does is save the user from needing to run separate power and network lines.

 

* The PoE spec also allows a method for "piggybacking" power on all four pairs, particularly for use with gigabit ethernet.

[securitysupplies 0]

can anyone please explain this 2 me. does the power travel without connections (in thin air) and is this possible? or have i got it all wrong and connections do have to be made all the way from one device to another, i only use my cameras for my own home security via plug and play cables and the only ethernet connection i have is from my dvr to pc. Can i use this POE with my system or is it mainly for ip cameras

 

Thanks

 

And there are some PoE splitter now in the market for simple use. Not necessarily buy expensive PoE switch...,etc...

 

Rgds, Dove

[securitysupplies 0]

can anyone please explain this 2 me. does the power travel without connections (in thin air) and is this possible? or have i got it all wrong and connections do have to be made all the way from one device to another, i only use my cameras for my own home security via plug and play cables and the only ethernet connection i have is from my dvr to pc. Can i use this POE with my system or is it mainly for ip cameras

 

Thanks

 

And there are some PoE splitter now in the market for simple use. Not necessarily buy expensive PoE switch...,etc...

 

Rgds, Dove

 

And I see it also depends on the equipment you're using, supply side and user side should match in voltage to have the whole set work.

 

 

Rgds, Dove

[Soundy 1]

And I see it also depends on the equipment you're using, supply side and user side should match in voltage to have the whole set work.

 

You shouldn't need to "worry" about the voltage... if the devices all conform to 802.3af spec, they'll operate at 48VDC. If they support the newer 802.3af-2008, they'll handle anything between 36-57VDC.

 

Regardless, the spec defines the voltage required; you don't need to know or check or compare them.

[Erron S. 0]

One thing to note when talking about POE switches and cameras. There are a number of POE cameras that are hitting the market now that are class 3, 14+watt cameras. (huge power draw cameras) I've seen a number of these exceed the maximum power rating on a few switches. Something to keep in mine when out bidding and specing.

[zmxtech 0]

yes most cisco`s do 16w per port, there are high power POE switches coming out.

the new cisco 1252 wireless access points cant run POE from the switch you have to use the power injector. [still POE tho]

 

most POE switches can sense the class of device and adjust the voltage range to suit. the 50v allows for heaps of voltage drop on long runs.

 

z

[aalbert 0]

If you are looking for a good PoE switch, the 3com 2426-PWR-PLUS can provide up to 30 watts to a port... It is limited to 180 watts of power across the switch, but we have deployed a bunch of these switches with no issues.