When I do a Capture&Solve with sync command, to my Rainbow Astro RST-135E, this is only partially incorporated in the alignment model in the mount. From the six alignment parameters (PA Alt/Az, RA/DEC error and DEC and RA/DEC orthogonal error), only two get updated (RA/DEC error). This is similar to doing a single star alignment using the handcontroller. But when repeating this 5 times using the hand controller, all 6 model parameters are populated and an actual alignment model is built. Repeating the process using Ekos does never populate all 6 model parameters. In fact it does not even register one single sync as a 'star alignment'.
From the forums it seems that in the ASCOM driver, you would have to select 'star alignment' when doing these syncs. Does something similar needs doing in Ekos/INDI? Or is 'star alignment' something that is not currently supported by the INDI driver? Hopefully this is just something I am doing wrong. With my 10Micron mount, doing star alignment using HC vs a sync from Ekos is doing exactly the same thing, so that was why I was hoping it would work the same way with the RST-135E.
When guiding, this is probably not so important as lack of an internal alignment model will be guided out. But I am trying to use unguided, which works reasonably well as long as the mount is well aligned and this 5-star alignment model is in place.
I think the RST-135 has the same issue. Only the first sync seems to result in any improvement in pointing accuracy. Since I plate solve and slew and then guide I never worried about it too much but this would explain it.
Thank you Thomas. That sounds indeed the same. So this might be due to the driver then. It would be great if this would be added in a future driver upgrade.
I asked Michel (MW4 developer) about this some months ago, and he was not interested in supporting other mounts. It's already a lot of development work for him supporting 10M mounts specifically.
The driver is the limitation. The protocol to sync multiple points wasn't provided for INDI.