#7 CommandString :FLIP_GOTO error.

[Denis Demyanov]

Hi!

When I try to use CommandString :FLIP_GOTO, 1# my program (C#) breakes with error: "Method CommandString<>::FLIP_GOTO,1 is not implemented by this telescope driver object."
But command :FLIP_GOTO, 0# works correctly.
And Get Flipped Goto status returns 0# when checked status of Force Flipped GoTo is true.

EQASCOM 1.27m and 1.27p

Denis.

[Chris Shillito]

Give EQASCOM V1.27q (on yahoo group) a go - think I may have it sorted.

Chris.

[Denis Demyanov]

Yes, it works, thanks!
But works with interesting logic. For example:

Example #1: Pierside west, pointing east (before meredian). Force Flipped GoTo is checked. Goto to point before meredian. EQMOD made flip pierside to east, pointig west.

Example #2: Pierside west, pointing east (before meredian). Force Flipped GoTo is checked. Goto to point after meredian. Ok. EQMOD made goto without pierflip. Again goto to another point after meredian. EQMOD returns scope to meredian and then goto to target point.

With example #1, I can fix it in my program by checking necessity of Force Flipped GoTo. But example #2 is out of my possibility. This returns to meredian takes extra time and upsetting...

Can it be fixed in future releases?

Denis.

[Chris Shillito]

Example#2 is actually working correctly. Whilst it may take a little extra time it is done with good reason.

Flipped movements are inherently dangerous with respect to mount collisions as they only ever occur when operation outside of EQMODs safety limits. To minimize risk of mount/equipment collisions, movements whilst in the flipped orientation are deliberately restricted to changes in RA only. So, if you change target EQMOD will first return the mount to a 'safe' position (as set by the RA limit if enabled or meridian if not) by moving the RA axis, it will then set the new position of the DEC axis and only when that is complete will the RA axis is moved to target. This really is the safest way movement strategy to cover all user setups.

The same is also true if you move from a flipped position to a 'normal' position. EQMOD will first move back to the meridian (or RA limit point) in RA only and then got to target by moving RA and DEC as required.

Hopefully I've explained this well enough but if not I did record a youtube video that illustrates the movement strategies using my own mount.

Chris.

[Denis Demyanov]

Ok. I understand this strategy. But I tried to goto with the exact same Dec value (was RA 11h Dec0, goto RA 9h Dec0) and mount returns to meredian and then goto. May be shall get to user some limit of Dec changes from start position to goto position, when mount will not return to meredian? Or make some commandstring, that will allow goto without returning to meredian only by thirdparty program? Something like FLIP_GOTO2.

P.S. Sorry for my english, this is not my native language.

Denis.