P9/P10 Boards dbm levels

Has anyone else noticed aprox. 10dbm less if you look at an SM that has P9 hardware and it’s associated AP that has a P10 board? This is the same visa versa. It’s seems to me that all P10 boards that we have are reading 10db less than what it should be. Is anyone else having this problem?

Yes I’ve seen it on the P10 boards since day one. I told moto about it and sent them my findings. They said it affected 5.2,5.4,5.7 and 2.4 SM’s but not 900 sm’s. However I’ve seen theis same problem on the 900’s as well, and again I told moto about it, but they said it was just a defective SM and that I should RMA it. I’ve seen it on alot of 900’s…they must be producing alot of defective SM’s by there reasoning.

Yep.
They are working on it. Expect to see corrections in v9

Thank you, I’m glad I’m not the only one seeing this issue.

I have seen this on some of our enhanced SMs, where customers have 100% both ways on the link tests but show 100db for connection. I was worried at first but I think it is a reporting glitch as customers are happy.

Is this hardware or software issue ?

Do we RMA or wait for the software ?

THanks !

Wait for software

abdock wrote:
Is this hardware or software issue ?


The issue has to do with the way the radios calculate the value, and I think what was meant by they are working on it, is that they are trying to do a better job of reporting a meaningful value.

All of the dbm, rssi, and jitter values in the radios are just educated guesses anyways... They take the rssi value, which is an internally generated figure and then do math on it based on the calibration values to get the dbm. My understanding is that it isn't all that linear and some radios are more accurate than others.

Assuming that the radio is working fine, then I'd just say ignore it....and hope the newer software reports a better value.

-forrest

I should also mention that there is also a known issue with P10 boards which results in around a 20db actual loss in either TX or RX power, or both due to a t/r switch failing on board. The newest boards supposedly don’t have this problem, but you never know how long SM’s have been in the channel. Typically this occurs within a few hours/days of the SM being put in service.

This particular issue will cause both bad RSSI and dbm figures, and will typically impact the SM’s ability to operate corrrectly (that is, will result in bad link tests).

This is different than the reporting issue I mentioned in my previous post, which is simply inaccuracy in the reporting of the dbm data…

-forrest