[carbo]

First, forgive me if I am mixing up some details.

I have been using separate pairs of OPLMs for each vehicle, since the OPLM on vehicle needed to be coordinator or otherwise the connection would break soon and not be re-established during flight. Is this still the case or has the issue been solved?

[hwh]

Have you gotten new oplinks?   The reason you needed to make the air side the coordinator is that the hardware you're using is defective.  There's no issue in the firmware that requires that.

[carbo]

>the hardware you're using is defective
Could you elaborate or point to another thread I might have missed? How do I identify good and bad ones? My OPLMs are old, I have a mix of dark ones (are they actually green or black?) with angled connector and white ones with straight connector, all from store/newstore.openpilot.org. Also Revos from different Openpilot batches.

[hwh]

...Could you elaborate or point to another thread I might have missed?...

Just click on Home at the top of the page so you're searching all the sub-forums and search for oplink.

...My OPLMs are old, I have a mix of dark ones (are they actually green or black?) with angled connector and white ones with straight connector, all from store/newstore.openpilot.org. Also Revos from different Openpilot batches.

That's more unusual, I don't remember anyone else saying they're having problems with "genuine" oplinks from the OP store.  All the posts I've seen involved Chinese clones with bad RFM22b modules.  Most of them have the chip markings removed.

What was the response when you told them that they didn't work properly back when you purchased them?

[carbo]

Actually it was an issue that came up last year, long before chinese clones became available, but sadly I don't remember every detail. I am not sure, may have been in OP forums or OP or OPNG chat. Maybe someone who was around back than has a better memory than me.

[hwh]

None of the developers who've been online today remember anything like that, including several that were with OP for years before the split.  If a bug report had been filed one of them would probably know.  It may have been something that just came up in the forums and the developers never heard about. Or as you say, something from OPNG after the split.

Either way, I know of only two reasons to have the coordinator in the air:

The first is that some of the Chinese oplinks use clones of the Hope RF RFM22b modules that are off frequency, the bad ones I had were about 100 KHz high and even reversing roles didn't help them.  I fixed them by replacing the RFM22b modules with real ones.  Some of the ones that are off by a smaller amount can connect with the roles reversed if the air transmitter is closer to the correct frequency than the ground one.

The second has to do with telemetry for the OSD, if the air oplink is the slave and loses the connection to the ground the telemetry to the OSD stops too.  If the air one is coordinator the OSD still gets telemetry even when the oplinks aren't connected. I haven't tested this for myself. 

The second is a known limitation in the telemetry design and was probably discussed in the old forums.  It may be what you're remembering. I miss the old forums, there was a lot of information in them.  It's too bad they were erased instead of given to someone to keep online.

As far as I know unless you fly at distances where the RC transmitter and OSD video work but the oplink disconnects there's no reason to fly with them reversed.

Sorry for the long, rambling post, usually I only ramble on like this late at night when I'm bored...

-Hank

[carbo]

>The second is a known limitation in the telemetry design and was probably discussed in the old forums.  It may be what you're remembering. I miss the old forums, there was a lot of information in them.  It's too bad they were erased instead of given to someone to keep online.

That's it! Thank you.