The issue is that the standards-based PoE (3af/3at) add some relatively expensive components to the device cost. If you know that 99% of the time the device will be used with PoE with a supplied injector, passive PoE makes a lot of sense from a cost perspective. If you know that most of the time it will be used with a PoE switch, better to use standards-based PoE and skip including a power adapter to offset the cost.
There is also a cost difference between 24V and 48V passive PoE although I'd say these days that difference is insignificant. -Hal On Mon, Jan 4, 2016 at 11:13 PM That One Guy /sarcasm < thatoneguyst...@gmail.com> wrote: > my mind just melted > > On Mon, Jan 4, 2016 at 8:29 PM, Eric Kuhnke <eric.kuh...@gmail.com> wrote: > >> Time to connect a power-over-ethernet and ethernet-over-powerlines >> adapter in a loop and create free limitless energy. Who needs the >> E-cat????!?! >> > On Mon, Jan 4, 2016 at 4:47 PM, Jaime Solorza <losguyswirel...@gmail.com> >> wrote: >> > Stop making sense... it's disturbs the space time continuum >>> On Jan 4, 2016 5:33 PM, "That One Guy /sarcasm" < >>> thatoneguyst...@gmail.com> wrote: >>> >>>> POE is quite the crackwhore of terms nowadays, alot of people use her >>>> in alot of different ways and nobody wants to pay much. I wish there was >>>> just a design standard that just auto sensed and applied, 24v 48v pick a >>>> pair. Just to eliminate the additional stocking of appropriate power >>>> supplies and surge suppression, they would be worth a little more, and if >>>> it were to become common the cost would drop >>>> >>>> On Mon, Jan 4, 2016 at 5:30 PM, George Skorup <geo...@cbcast.com> >>>> wrote: >>>> >>>>> I believe Phihong wired it that way so that you can use it as a 3at >>>>> compliant injector where only two pairs may be present (so 10/100 only). >>>>> IP >>>>> phones come to mind. We run into a lot of older-ish structured wiring >>>>> where >>>>> they ran only one cat5 and stole one pair for phone and two pairs for >>>>> ethernet. Not the way I'd do it, but whatever. Most of the phones we're >>>>> using now have a built-in GigE switch. >>>>> >>>>> I remember seeing in the 450i guide that it will take either polarity >>>>> on all pairs. If you're not using the aux port, then two pairs for power >>>>> (30W) will be fine. If you are, or I suppose if it's a long run, then all >>>>> four pairs for power would be warranted. I really like this PoE design. >>>>> Would be nice if the regular 450 APs would take 48-56VDC. I know they >>>>> talked about that at one point, but it looks like we're limited to 30VDC. >>>>> Well, at least that's what the label says. >>>>> >>>>> The whole pin swapping thing with the 450i and CMM4 is because 56VDC >>>>> mode on the CMM4 is wired for the split pair 320/430 config. With the AP >>>>> being pair polarity agnostic, you don't need to do the swapping when using >>>>> a SyncInjector. Basically it will take the standard Canopy POE pinout, >>>>> just >>>>> needs to be >=48VDC. Probably more like >40VDC. >>>>> >>>>> On 1/4/2016 12:50 PM, Ken Hohhof wrote: >>>>> >>>>> Good point about the power being on 1/2 and 3/6. I guess that makes >>>>> it 802.3at Alternative A wiring. According to the schematic, 4/5 and 7/8 >>>>> are wired straight through with no transformer. So gigabit compatible >>>>> with >>>>> only 2 transformers. Probably for non gigabit compatible, Alternative B >>>>> is >>>>> cheaper because you don’t need any transformers at all. And the 60-75 >>>>> watt >>>>> POEs use all 8 wires for data and power, so 4 transformers. >>>>> >>>>> So confusing! >>>>> >>>>> I can’t find any wiring diagrams for the Cambium N000065L001B, but at >>>>> 60 watts, I guess it must use all 8 wires for power. Hence the price? >>>>> >>>>> Something else I notice is the Cambium POE is rated for 0 to 40C, >>>>> while the Phihong unit is rated –20 to +65C. Cambium tells you to use a >>>>> PIDU for non controlled environment. Or Netonix or GIGE-POE-APC or >>>>> Syncinjector. >>>>> >>>>> Still, AC powered POEs are handy for configuring radios on the bench, >>>>> or like that case where I needed a POE at a customer’s office to power a >>>>> SIP paging amplifier. >>>>> >>>>> >>>>> *From:* George Skorup <geo...@cbcast.com> >>>>> *Sent:* Monday, January 04, 2016 2:35 AM >>>>> *To:* af@afmug.com >>>>> *Subject:* Re: [AFMUG] 802.3at POEs >>>>> >>>>> It's cheaper at Allied: >>>>> http://www.alliedelec.com/phihong-poe36u-1at-r/70124112/ >>>>> >>>>> Yeah, if you're not going to use the Aux port on the 450i, there's no >>>>> reason to buy a 60W injector. Just keep in mind that this Phihong injector >>>>> is power over the 10/100 data lines. And is - on 1&2, + on 3&6. It'll work >>>>> perfectly fine with the 450i APs and 5GHz SMs. And obviously the Exalt >>>>> ExtendAir G2. The 450i is awesome with the any pair power setup. >>>>> >>>>> The one thing I will say about this thing is that it runs a bit hot >>>>> and if your hearing is decent, you can definitely hear the switcher >>>>> whining >>>>> away. >>>>> >>>>> On 1/3/2016 7:29 PM, Ken Hohhof wrote: >>>>> >>>>> I'm getting more and more equipment with 802.3at POEs, and I feel like >>>>> I'm getting raped on the price if I get the POE from the equipment vendor. >>>>> High price and minimal features. >>>>> >>>>> My Exalt G2 radios came with these really nice POEs that have >>>>> diagnostic LEDs and tabs for wall mounting as well as rubber feet for >>>>> desktop use. The only downside is they are kind of big, but that's not >>>>> necessarily bad, that may help prevent overheating. It has LED >>>>> indications >>>>> for valid 802.3af and 802.3at signatures, as well as a flashing overload >>>>> indication. >>>>> >>>>> I looked up the part number, expecting them to be expensive, but >>>>> Digi-Key has a bunch of them in stock and the price is quite reasonable >>>>> ($38 in single quantity). >>>>> >>>>> >>>>> <http://www.digikey.com/product-detail/en/POE36U-1AT/993-1088-ND/2384576> >>>>> http://www.digikey.com/product-detail/en/POE36U-1AT/993-1088-ND/2384576 >>>>> >>>>> From the picture, this is also the POE that I should have gotten from >>>>> CyberData to go with the SIP paging amplifier I bought, but instead they >>>>> sent a cheaper L-Com POE that has just one dumb LED to show it is getting >>>>> AC power. So I paid something like $64 for a $31 POE. >>>>> >>>>> The $100 Cambium POE for 450i is probably more than 36 watts in case >>>>> you want to use the AUX port on the AP, but it lacks the nice mounting >>>>> tabs >>>>> and diagnostic LEDs. And 36 watts should be more than enough to power >>>>> just >>>>> the AP. >>>>> >>>>> So I’m inclined to just buy a bunch of the nice Phihong units and use >>>>> them on everything. Am I missing something? >>>>> >>>>> >>>>> >>>>> >>>> >>>> >>>> -- >>>> If you only see yourself as part of the team but you don't see your >>>> team as part of yourself you have already failed as part of the team. >>>> >>> > > > -- > If you only see yourself as part of the team but you don't see your team > as part of yourself you have already failed as part of the team. >
