FCS / CRC errors

[Stephen]

I am unable to reproduce. But I have a wild guess. Are all of your new switches on the new fans? The base frequency of PWM on the new fans is higher than the older ones (out of necessity, the manufacturer gave us no choice in the matter). Maybe that is introducing noise?

[Omniflux]

I'll have to check, but I think they are. Is there a simple way to test, or will I need to open one up and unplug the fan (and would that actually be sufficient?)

[Stephen]

Removing them or replacing them with old fans (and re-running the fan test so the switch switches modes) should do the trick if that's the problem.

[sakita]

"Everything works well if I power the Mikrotiks directly"

I have 24 of those MikroTik CCRs and when I tested they didn't seem to work correctly on PoE power. In any case, we run all of them on the power plug on the back of the unit.

I wonder if it is something with how the MikroTik takes in PoE power? Maybe noise as Stephen is suggesting?

Have you tried using a PoE splitter to split PoE from the Netonix and feed it to the power input on the back of the MikroTik? (I have not tried this having just thought about it).

[Omniflux]

I opened a new unit up and unplugged the fan, powered it on and ran the fan test. After it reported ERR, I ran traffic over the links and....no errors!

Is there a way I can shut off the fan via SSH so I can test this on some remote units without having to take them offline?

[Dave]

are you powering with 24 or 48 volt POE power?

[Omniflux]

24V Battery into Netonix

24V PoE Ubiquiti
48V PoE Mikrotik

[Stephen]

There used to be a fan override in the software but at request it was taken out awhile ago.

From what we've seen so far it seem's that the fan's PWM frequency (which is now 24KHz) is acting like a local oscillator and heterodyning with the baseband coming out of the rocket. It might be that people using the AC switches don't see this because all the image's are grounded by the AC plug.

If possible/practical you might also have luck by changing the baseband frequency of the radio?

[Dave]

Stephen...I have my doubts...both AC & DC models have the same fans running. And the Mik is running from the 48 volts, the fans use the 24 volts.

More than likely, the Mik is not filtering its incoming POE power good enough as a guess.

[Stephen]

Oh yeah, those are separate line's. At this point probably best to listen to the actual hardware engineer on the topic.

On the software though, no, there is no fan override feature right now. I could potentially put it back it soon though.