POE video cameras

I have a question about power over ethernet video cameras.
 
In a POE system, where does the power originate? I currently have a system with three switches that do not support POE. If I was to add a fourth POE capable switch downstream from a non-POE switch would a POE device work when connected to it? Does the power for the device originate at the POE switch?
 
Mike.
 
EDIT
 
Also - If I add a POE injector to the system will the non-POE switches then power a POE device?

Either from the POE switch or midspan. If you only have one or two POE devices it's easier to usually just buy a midspan and call it a day. Many POE switches have a limited power budget and say bulleted terms like 60W available! but it's divided across all the ports vs. each.
 
A POE device needs to be plugged directly into whatever is powering it and not via proxy (midspans are TCP/IP passthru). Theres only a couple of variations for devices that regenerate and passthru POE so they shouldn't be brought  into the discussion.
 
How you stack the switches is another conversation altogether.

DELInstallations said:

Either from the POE switch or midspan. If you only have one or two POE devices it's easier to usually just buy a midspan and call it a day. Many POE switches have a limited power budget and say bulleted terms like 60W available! but it's divided across all the ports vs. each.

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Thanks, good point
 

DELInstallations said:

A POE device needs to be plugged directly into whatever is powering it and not via proxy (midspans are TCP/IP passthru). Theres only a couple of variations for devices that regenerate and passthru POE so they shouldn't be brought  into the discussion.
 
How you stack the switches is another conversation altogether.

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I use a few of these and one Tycon 24 port midstream managed injector.
 

 
Tycon Power Systems

Altronix would be my suggestion for a multi-port unit but Lanpower has also gotten me out of a bunch of binds.

Be aware of standard POE (802.3af/at) and non standard 'Passive POE'.  The latter is an ad-hoc mechanism of simply putting DC on unused pairs of the cable.

DELInstallations said:

Altronix would be my suggestion for a multi-port unit but Lanpower has also gotten me out of a bunch of binds.

Click to expand...

+1
 
I picked up a  1u 16 port Altronix Netway midspan for cheap on ebay a year or two ago  Works great.

I generally either use singular POE injectors like this:
 
http://www.amazon.com/PowerDsine-Injector-AC-802-3AF-Supported/dp/B000A0S98A/ref=sr_1_1?ie=UTF8&qid=1440785202&sr=8-1&keywords=powerdsine+poe+injector
 
Or (most commonly) POE switches like these:
8-port POE: http://www.newegg.com/Product/Product.aspx?Item=9SIA1EA36R1350&cm_re=dlink_poe_switch-_-33-127-513-_-Product
4-port POE: http://www.newegg.com/Product/Product.aspx?Item=N82E16833122152&cm_re=netgear_poe_switch-_-33-122-152-_-Product
 
My issue with the Tycon type is that they require a separate power supply (as in purchased separately); but they are useful when non-standard POE is required - some devices I've used require 12-30VDC rather than 48VDC. In these cases, the Tycon is definitely the way to go as they just pass-through the supplied power.

mikefamig said:

EDIT
 
Also - If I add a POE injector to the system will the non-POE switches then power a POE device?

Click to expand...

 
No. The power will only be supplied by a POE port to a POE device. When the connection is initially made, there is a "handshake" that occurs between the devices to determine if POE is to be supplied or not; thus the port will not supply power unless "requested" by said connected device. So, you can plug your laptop or computer into a POE port... and no power will be supplied to your laptop.
 
What you would want to do, is connect your existing infrastructure (assuming you want to keep all of those in place) to POE switches/injectors that would then supply power to your POE devices (e.g. cameras). Doing so would allow data exchange between the switches (as normal), and power+data to the POE devices.  

Yah; the little Tycon switches are more for solar / battery outdoor use of DC power AP's and Cams.  The power / pin connections are clearly labeled.  The midstream power upstream port does pass POE to the device itself.  They are little workhorses.
 
The big one 24 POE injector has four autonomous power supplies which provide standard POE power.  Only the power pieces of the midstream switch (not really a switch) are manageable. 
 
Here using POE splitters (standard in and 5VDC out) for the tabletop touchscreen tables (5VDC)

drvnbysound said:

No. The power will only be supplied by a POE port to a POE device. When the connection is initially made, there is a "handshake" that occurs between the devices to determine if POE is to be supplied or not; thus the port will not supply power unless "requested" by said connected device. So, you can plug your laptop or computer into a POE port... and no power will be supplied to your laptop.

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That is true, however in the specific case of cameras, there's a lot of harm vs. good that can be done and specific attention needs to be paid to the product and what it's intended flavor of POE may be.
 
As an example, AD cameras will power up and run on POE, however they require high power POE, past POE+ (50-60 watts normally) and will run. If you power them with a separate supply and then put POE on them they'll last about a week before blowing up....even their own engineers didn't have this answer.
 
Axis, as another, with their cameras that come with a high powered injector, if you put POE to the injector, even though it doesn't pass thru and the injector isn't supposed to be "smart", the injector itself then underpowers it's output and causes all sorts of camera phantom issues due to the improper output, though the midspan meters fine.

DELInstallations said:

That is true, however in the specific case of cameras, there's a lot of harm vs. good that can be done and specific attention needs to be paid to the product and what it's intended flavor of POE may be.
 
As an example, AD cameras will power up and run on POE, however they require high power POE, past POE+ (50-60 watts normally) and will run. If you power them with a separate supply and then put POE on them they'll last about a week before blowing up....even their own engineers didn't have this answer.
 
Axis, as another, with their cameras that come with a high powered injector, if you put POE to the injector, even though it doesn't pass thru and the injector isn't supposed to be "smart", the injector itself then underpowers it's output and causes all sorts of camera phantom issues due to the improper output, though the midspan meters fine.

Click to expand...

 
Sure, there are always exceptions... I suppose I could add the * that I was primarily referring to the majority of cameras that would be used in a residential installation. I'll also * that I almost exclusively use Hikvision cameras - VERY hard to beat for <$100.

I rarely see the point in midspan adapters these days unless you only need like 1 port or you're using a special use case (I have a >700' run with a POE radio at the end - getting power boosted/repeated by a high-power midspan injector)...  for about the price of a midspan injector you can get the cheap TP-Link 8-port switch with 4 POE ports.  That said, my personal favorite of the small switches and a model I have several of is the Netgear GS110TP.  I keep them on my desk and in my closets powering my cams and phones.  That model has been around at least 5 years and is still sold new.  It supports VLANs, gigabit, and even has two SFP ports which can be great for attachment to a detached garage or workshop.
 
There are of course exceptions to every case but the standard residential cams will generally be fine on a lower end 802.3af switch.  And as covered above, every port is its own power supply - there's no splitting or anything like that.  However, there is such a thing as cascading POE using special switches that can not only receive their power from the main POE switch, but still power 2 POE devices downstream... but they have limited power cases.  Great though because they keep the UPS in the main closet.  
 
And I think it's well covered above but to clarify - it doesn't matter how many switches you have cascaded - the POE devices must be plugged into a POE switch - but the POE switch can be connected to several other non-POE switches upstream - that's no big deal.

Thanks for all the good input.
 
I currently have three Foscams powered by individual AC adapters and am planning upgrades and additions. It looks like a couple of strategically placed 4 - 8 port switches will do me.  From all that I've read here the HKvision cams are popular and I have had good luck with both Altronix and Netgear equipment. I think that with the help of Ebay I should be able to make a plan that won't break the bank.
 
Mike.

Yeah here the reason for my Tycon switch postings are that I did purchase a few in bulk (new) on Ebay a few years back.  Inside here have settled mostly on using TP-Link managed switches, small POE switches, TP-Link POE splitters for my touchscreens. 
 
Playing with this stuff also initially purchased Grandstream OS camera IP HD POE boards and put them in Speco domes.  They fit nicely and the Speco domes where outdoor IP-XX.  That said have gone to using all Grandstream IP cams now integrating it with legacy stuff, ZM, Grandstream decoder, Grandstream NVR (still in box).  Mostly outside are dome style cams.  (do have two bullet cams).  All of the Grandstream OS cams have built in SIP. (along with what else cam related that Grandstream sells).  Guess too stuck with Grandstream OS cams to be able to do the same with all of them.   Wrote here about the endeavors.  Vendor also did provide me with tools to adjust / change base OS / GUI.
 
I also for a time played with the Ubiquiti IP cams.  Very simple and function no frills IP camera.
 
Favorite outdoor lens style is 28mm (now you get get digital / analog zoom), 3-5 MP, external motion connectors, et al.  Most of the new IP HD POE cams also use much less power than the older / first generation cams.
 
I did also integrate all of the newer cameras with the legacy HAI stuff (Omnitouch screens / Omnitouch video hub / et al).
 
I have read many good things about the sub $100 HKvision cams.  Many folks seem to like the dome camera look for outside over the bullet style.  Well and the newer bullet style are really short these days.