I think 4 minutes if it was Alaska cold :P Josh Luthman Office: 937-552-2340 Direct: 937-552-2343 1100 Wayne St Suite 1337 Troy, OH 45373 On Jan 21, 2016 11:08 AM, "Adam Moffett" <dmmoff...@gmail.com> wrote:
> They have said there's a resistive heater. I heard it in ePMP training in > Albany and I've seen it stated on this list. > > If I remember correctly (I might not), they wanted the CPU to hit a > certain temp before starting up. If it was too cold you'd see a delay in > startup of up to 2 minutes while waiting for this heater to bring the CPU > up to temp. I've never actually observed the delay, so I guess they're > talking about Alaska cold, not NY cold. > > > On 1/21/2016 10:47 AM, Forrest Christian (List Account) wrote: > > I looked at the high resolution photos on the FCC site and didn't see > anything obvious. Now I've got the one I have on the bench out of the > case, I still don't see anything obvious heater-wise, but again I'm not > going to pop the shields off the board (requiring desoldering), to be 100% > sure... > > On Thu, Jan 21, 2016 at 8:30 AM, Steve D <bigd...@gmail.com> wrote: > >> Just throwing this out there, but don't the epmp's have a small heater in >> them that could be turning on when it's cold, drawing additional power? I >> recall it was supposed to pre-heat components to avoid freezeup on first >> boot but I can't recall if that's the only time they run or not. >> >> -Steve D >> >> On Thu, Jan 21, 2016 at 1:44 AM, Forrest Christian (List Account) < >> li...@packetflux.com> wrote: >> >>> I do want to clarify one item: >>> >>> This is not necessarily related to the cambium DRAM issue. I don't >>> want to claim that problem, since this isn't the same thing. This is more >>> of an issue where you have ePMP's which seem to start having power-related >>> issues. If moving to a 30V brick makes your problem go away, then the >>> issue I describe below probably is your issue. If moving to a higher >>> voltage doesn't fix the issue then this probably doesn't relate to your >>> issue. Regardless, it is my intent to recommend that my customers move to >>> 48V as soon as I confirm that this seems to fix at least a decent number of >>> the problems without causing others. >>> >>> Unfortunately this might be a case of the cold weather aggravating two >>> separate issues (or for that matter, the cold weather causing increased >>> current consumption in the ePMP, which then requires a higher voltage to >>> operate correctly). >>> >>> -forrest >>> >>> On Thu, Jan 21, 2016 at 12:43 AM, Forrest Christian (List Account) < >>> li...@packetflux.com> wrote: >>> >>>> A bit of an update from the PacketFlux side. >>>> >>>> Late this afternoon I received a ticket from Tyson in relation to these >>>> issues. In particular, sync from a PacketFlux SyncInjector dropping off on >>>> an ePMP when it's cold. I have spent a bit of time this evening >>>> investigating this issue. The following is a summary of what I found. >>>> It's a bit long-winded so that those experiencing the problems can >>>> understand my current working theory and help me figure out if this is the >>>> case. >>>> >>>> WARNING: The following is based on a limited amount of testing with a >>>> single ePMP with no traffic and no clients and on a bench. This is likely >>>> the best case scenario. The field is only going to be worse. >>>> >>>> The setup is as follows: >>>> >>>> ePMP 1000 GPS AP, with no GPS hockey puck attached, connected to a >>>> Gigabit Syncinjector (Rev H and Rev I - I have a special one with a port of >>>> each 'type' ;-) ). I am powering the injector with a variable power >>>> supply so I can vary the voltages in. The AP is connected to the Injector >>>> with ~100m of CAT5 cable. The Antenna connectors have terminators on >>>> them, the AP is in transmit mode, but isn't passing any traffic since there >>>> are no clients. >>>> >>>> When feeding the injector with 24V, I get about 23V at the AP. This >>>> is pretty consistent with what I would expect in this situation. The AP >>>> seems to work fine, at least on the bench and without doing any real >>>> work. However, as the voltage drops, things start to get weird: >>>> >>>> At around 22V in, (21V at the AP), Sync becomes flaky. This is >>>> consistent on both H and I version ports on the injector. Sometimes it >>>> works, sometimes it doesn't. Note that 22V is the bottom of the rated >>>> voltage inputs for the ePMP. >>>> >>>> At around 20.5V in (19.5V at the AP), the radio just turns off. It >>>> won't turn back on until around 22V. >>>> >>>> Now here's where some total speculation comes to play. On the bench, >>>> this unit is drawing around 3W. Let's assume that under load, and when >>>> temperatures are cold, this unit draws closer to 6W. This would double the >>>> current, and quadruple the voltage drop. Now, assume 24V in, this puts you >>>> at around 20V in at the AP, which is about the turnoff point. Remember >>>> this is on 100m of wire, and a total speculation about a the power draw of >>>> a cold, under load AP. But the point is valid, regardless of the cause - >>>> if the circuit resistance when combined with the power load causes a low >>>> enough voltage at the AP, weird things will happen. And since weird things >>>> seem to start to happen around 22V, there just isn't much headroom at >>>> 24V. >>>> >>>> This explains why things work well at 30V. >>>> >>>> For those who are having this problem I'd recommend trying increasing >>>> the voltage into the SyncInjector. The Revision H injectors can safely >>>> handle up to around 56V or so. Assuming all of the radios on an injector >>>> are either ePMP or the newer 450i's, using 56V into a SyncInjector is >>>> perfectly acceptable and the ePMP's are rated up to 56V as well. >>>> >>>> So the summary: Try a 48VDC voltage source instead of 24V and see >>>> what happens. >>>> >>>> -forrest >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> On Wed, Jan 20, 2016 at 11:00 AM, Tyson Burris @ Internet >>>> Communications Inc <t...@franklinisp.net> wrote: >>>> >>>>> Hello Cambium, >>>>> >>>>> >>>>> >>>>> At the MidWest-IX launch party last night, several of us Indiana WISPs >>>>> compared notes on the ‘cold weather’ problems we are seeing with ePMPs. >>>>> It >>>>> was very interesting to learn we are experience identical problems across >>>>> the spectrum. >>>>> >>>>> We all understand this is a DRAM issue with certain units you have >>>>> identified. We also understand the firmware RC that has been made >>>>> available to fix this short term. >>>>> >>>>> The bottom line is we are very frustrated and grow tired of dealing >>>>> with it. >>>>> >>>>> >>>>> >>>>> Our concern is simple. If your software fix ‘degrades’ the >>>>> performance of the product or triggers other issues, as it has been >>>>> suggested, we would prefer a full recall and replacement program >>>>> immediately. >>>>> >>>>> >>>>> >>>>> If the suggestion that the fix will degrade the product performance is >>>>> inaccurate and not cause other issues, I would like for this to be made >>>>> public. >>>>> >>>>> >>>>> >>>>> Thank you, >>>>> >>>>> >>>>> >>>>> *Tyson Burris, President* >>>>> *Internet Communications Inc.* >>>>> *739 Commerce Dr.* >>>>> *Franklin, IN 46131* >>>>> >>>>> *317-738-0320 <317-738-0320> Daytime #* >>>>> *317-412-1540 <317-412-1540> Cell/Direct #* >>>>> *Online: **www.surfici.net <http://www.surfici.net>* >>>>> <http://www.surfici.net> >>>>> >>>>> >>>>> >>>>> [image: ICI] >>>>> >>>>> *What can ICI do for you?* >>>>> >>>>> >>>>> *Broadband Wireless - PtP/PtMP Solutions - WiMax - Mesh Wifi/Hotzones >>>>> - IP Security - Fiber - Tower - Infrastructure.* >>>>> >>>>> *CONFIDENTIALITY NOTICE: This e-mail is intended for the* >>>>> *addressee shown. It contains information that is* >>>>> *confidential and protected from disclosure. Any review,* >>>>> *dissemination or use of this transmission or its contents by* >>>>> *unauthorized organizations or individuals is strictly* >>>>> *prohibited.* >>>>> >>>>> >>>>> >>>> >>>> >>>> >>>> -- >>>> *Forrest Christian* *CEO**, PacketFlux Technologies, Inc.* >>>> Tel: 406-449-3345 | Address: 3577 Countryside Road, Helena, MT 59602 >>>> forre...@imach.com | http://www.packetflux.com >>>> <http://www.linkedin.com/in/fwchristian> >>>> <http://facebook.com/packetflux> <http://twitter.com/@packetflux> >>>> >>>> >>> >>> >>> -- >>> *Forrest Christian* *CEO**, PacketFlux Technologies, Inc.* >>> Tel: 406-449-3345 | Address: 3577 Countryside Road, Helena, MT 59602 >>> forre...@imach.com | http://www.packetflux.com >>> <http://www.linkedin.com/in/fwchristian> >>> <http://facebook.com/packetflux> <http://twitter.com/@packetflux> >>> >>> >> > > > -- > *Forrest Christian* *CEO**, PacketFlux Technologies, Inc.* > Tel: 406-449-3345 | Address: 3577 Countryside Road, Helena, MT 59602 > forre...@imach.com | http://www.packetflux.com > <http://www.linkedin.com/in/fwchristian> <http://facebook.com/packetflux> > <http://twitter.com/@packetflux> > > >
