POE Smart

[sirhc]

No, wait, stop, let's do some thinking outside the box and not sit on some NIH attitude as a couple of people here are doing.

Maybe the full "cable test" function is overkill, so what if it was stripped down to the safety test essentials ...

OK, in the Email exchange with Dave, while I thought we could do a bit of brainstorming, I first brought up the idea, that since he has programmable MOSFET switches controlling POE power, could he essentially use them, plus the voltage/current sensors and the system processor to act as a programmable PWM voltage/current regulator? He explained that no, that basically the voltage/current sensors were not on a bus structure that was not fast enough to handle that type of continuous feedback regulation.

So I then said:

But imagine that you could probably program a free-running, narrow enough pulse width for an "on" 48VH port (for example) so that even without feedback monitoring, it would be just enough to power an unplugged port for an "ohmmeter" or "continuity" test function. (But not enough to burn out the Ethernet transformer.)

The processor wouldn't have to continually monitor that. It could come back every 3 seconds or so to see if the charge voltage on the per port output capacitor dropped more than an open port, but less than a shorted port? Only then would it would run it full on all the time. At least until such time that the current dropped below a certain level, indicating unplugged port, so that it could switch back to the "ohmmeter" state.

Sure, this would not fix the case of a bad cable randomly shorting out while in use. But maybe it could give it a chance to get past initial crooked plug in of a RJ-45 or a totally shorted new cable ... or new radio?

Unfortunately, Dave never had a chance to reply back since March 11, and I have had to deal almost continuously with a sick family member, so I also didn't have much time to try followups. I have long felt that the burned transformer exposure is a perceived hit to these switches being fully embraced as carrier class ...And I dooo want them to succeed as such and have spent a bit of time trying to come up with ideas around it that also encompass the idea of very low power loss for solar installations.

Without spilling the beans (SO DO NOT ASK I WILL NOT SAY MORE) for switches we are working on for NEXT year, or whenever the next generation of switches come out, there will be no issues/risk with people doing boneheaded things like this. That generation of switch will allow for POE to be on and you will be able to plug in a dead shorted cable and the switch will sense this fast enough and turn the POE OFF before any damage is done and then also sense that it is fine to turn POE ON so you will be able to plug and unplug live POE with our BLESSING but that is the next generation but for now I think this software work around is the best route.

Put it this way there has NEVER been a switch designed like what is in our R&D for the next generation in PASSIVE POE switches.

[wayneorack]

Wow! Safe passive 48 HV + 802.11at! Can I prerecord now? jk!

[sirhc]

Wow! Safe passive 48 HV + 802.11at! Can I prerecord now? jk!

I do not think we are doing 802.3anything, we could put it in there I suppose but WISP's do not need 802.3 but we will have an advanced POE protection design (hardware/software)which we are calling POE Smart™

We are just going to call this strictly software version POE Smart™ as well

[RebusCom]

If the user is turning POE on and it detects that no cable is there (0 meters long) or no device is plugged in which reports all pairs open it will also no turn the POE up and will turn it to OFF in the config and possibly send a message.

When you say turn it off "in the config", you mean off permanently, even through a subsequent reboot or power cycle? If so, then how would someone preconfigure a switch on the bench to swap out in the field with an existing switch?

[sirhc]

Well the tesch would swap the switch out, then log into the switch which his laptop and energize the ports?

But I am going to work with Eric and see if it would be possible that if a port is configured with a POE state but the switch detects no cable and or device that it would check every so many seconds for the cable and device then power up the port. But if the switch detects a cross short under any circumstances it will always set the port POE state to OFF or some special state to be determined.

This is all in the early stages of planning and we do not yet fully have the POE Smart defined in stone yet as we are not yet positive on what we can and cannot do.

[RebusCom]

Well the tech would swap the switch out, then log into the switch which his laptop and energize the ports?

Not all of my switches are at the base of the tower. You mean you are going to stop me from doing tower climbs by myself?

[sirhc]

We are not sure what were are doing at this point but people are obviously plugging live POE devices in and many times without first running a cable diagnostics and blowing the Ethernet transformer on that port because they have a short or a mistaken crimped end. (READ FROM THE TOP POSTS PAGE 1 DOWN)

The problem is people make a mistake and pop the transformer then want to RMA the switch for replacement.

Speed limits on public roads we set because the "few" drove way too fast and wrecked so we all have speed limits. There are people who stood on the top step of ladders and fell then sued the ladder company for their all be it questionable actions.

We do not want people plugging in POE ports "live". Now as I said in the beginning of this post the most common line is "I did this with my ToughSwitch all the time".

FIRST - There is a HUGE difference between 24V .5A and 48VH at 1.5A and as I said these poly fuses are rated higher than that from a cold start so there is no way the Ethernet transformer will survive a dead short.

Now I think we did pretty good with our isolated circuit design on our switch so that "if" you dead short one of our ports that port is toast and the rest are fine because if you dead short a UBNT 48V port or even sometimes a 24V port you can destroy the entire switch or at least that has been my experience with them in the past.

Also the fact that we took such care as to isolate the board voltages from the POE voltages and thus the ESD ground the other day I took my first radio loss in 4 years on a tower due to a lightening storm. Sadly it was an AF24, friend the whole unit no lights nothing and the surge came DOWN the Ethernet cable and took out that port and left the rest of the switch unharmed for the most part. Now that is not to say all lightning stories will end that way as lightening is not predictable.

Now that is different than losing a switch from NOT having the Electrical service ground bonded to your tower ground which normally sends a surge UP the Ethernet cable and fries just the Ethernet port in the radio but leave the radio portion of the device functional. ALWAYS BOND TOWER GROUNDS TO ELECTRICAL SERVICE GROUNDS!!!

Look, plugging "passive" POE devices into live ports is NOT a good idea!
Not running a cable diagnostic on a new cable run is NOT a good idea!

We are trying to figure out away to protect the end user from an OH-CRAP moment and we are trying to protect us from peoples OH-CRAP moments.

But How we currently build switches is "I" personally sit at the end of the line and flash and assign MAC address to each switch. I always by default plug into port 1 to do this and I almost always check the 48VH ports cause these are the most important ports on the switch. I do generally check several other random ports before I hit enter and print the labels. Anyway with that said I have taken 2 switches back where the end user "claimed" port 1 never worked from when they received the switch and after reviewing the switch it was found that the Ethernet transformer was blown so not to say that it is not impossible for the Ethernet transformer to be blown all by itself but......

So we think it would neat if we could prevent this from happening, everyone does boneheaded things INCLUDING me, I have fried a couple ToughSwitches in my day but I will be honest I did not send them back for RMA it was my fault.

So we are thinking this is a great feature to prevent this, even if we did not do it and just replaced switches as we have been doing the end user is still out a switch for a couple weeks which is bad. Why not try and come up with a solution that prevent this plus when it checks the cable it will notify you that the cable is not shorted maybe but errors are detected.

It is a work in progress, currently at the brainstorming level.

[RebusCom]

I'm not suggesting it's a bad idea. I'm just trying to determine if you've been talking to my wife. For years she's been telling me to stop climbing by myself.

Seriously, I do unavoidably have a particular configuration where power and much of the equipment is on top. In that case after the climb up I simply power down the old POE switch, swap units, then power the new one up. This way it does not involve plugging in anything while hot but the unit does need to be preconfigured so I don't have to climb back down to access the device and change config. That would increase downtime from under a minute to tens of minutes. (And you wouldn't want to rush me climbing back down, would you?)

[lligetfa]

If you have spare devices kicking around, you can always plug them in with short jumpers to satisfy the idiot-proof test. The biggest challenge would be satisfying the 48VH with spare kit.

Is there a way to copy the config over?

[lligetfa]

Also, if there was a mobile app, you would not need to take a laptop up with you, just your phone.

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