Double values in mount Rate dropdown menu

[Menno555]

Hi Robin

This was in the previous version but also now in version 4.0.9011.0 (64-bit). This was not so a few versions back.
The mount Rate dropdown menu contains double values, see screenshot.
This with a Ioptron CEM25EC mount. No change/update of Ioptron software.

Menno

Clipboard02.jpg (44.63 KiB) Viewed 533 times

[admin]

Hi Menno,

I think I know what is happening - there was a bug that was incorrectly excluding some rates... That bug is now fixed, which means some rates that were missing are now showing, revealing *another* slight bug. I think we will find that there are rates like 1x sidereal and 1.25x sidereal that are both being displayed as '1x' due to rounding.

If you can post me a log file that contains the connection to the mount driver I can investigate (the log will contain all the info about the rates the mount claims to support, so I can then debug the code with that data to see what is gonig on).

cheers,

Robin

[Menno555]

Hi Robin

I doubt that there were slewing speeds excluded here? The CEM25EC mount has 9 slewing speeds: 1×, 2×, 8×, 16×, 64×, 128×, 256×, 512× and 1440x (Max). The handcontroller shows this too and so does the Ioptron Commander software. Other mounts like the CEM60 also have 9 speeds. This is also in the specifications on their site and manual.

I did check the log (attached here too) and in there are some different values.
At 00:13:08.236224 #1 for example, it states that the mount has 12 available slew rates.
At 00:13:08.245177 #1 is says that Axis 0 has 9 slew rates.
At 00:13:08.246199 #1 it says that Axis 1 has 9 slew rates.

Also at 00:13:08.249190 #1 it says After testing, the following slew rates are valid: there are indeed more than 9 slew rates but the values there are strange? For example 1,99453916666667 and 2. That difference of 0,006 is of course not something that one would ever notice as difference in slew speeds

Menno

Log_2022-06-08T00_00_32-12180.zip

(12.38 KiB) Downloaded 18 times

[admin]

Hi Menno,

thanks, that should let me work things out. The ratio 0.99726... is the ratio of the length of the sidereal day to the length of the civil day, but I can't quite see yet how it gets into the rates Some debugging will sort it no doubt.

cheers,

Robin

[Menno555]

Glad to help Robin.

But now that I mention this on my mount, a question: does SC do anything with software on backlash or stiction correction? I have some weird manual slew problems on RA that I can't seem to fix. It's like there is something overcorrecting the RA slew movement when I start and stop that.

Menno

[admin]

Hi Menno,

no, SharpCap doesn't do any backlash or other corrections for mount movement. The only backlash correction in SharpCap is for focuser movements.

cheers,

Robin

[Menno555]

Hi Robin

Latest version fixed the double mentioned slew speeds.
Like usual great work

Menno