helgeras It said that it was moving telescope, but nothing happened,
Except for EQMOD, the "auto meridian flip" for the ASIAIR is a false claim. AISAIR does not know how to Medidian Flip any other type of mount. All it does is to issue a GOTO to a mount, and if the mount thinks the target of the GOTO has moved from before the meridian to the after the meridian, the mount issues a Meridian flip.
The EQMOD mounts are different, since the EQMOD software that ASIAIR uses does issue a Meridian flip -- but again, technically, ASIAIR does not flip -- the EQMOD library flips, and ZWO has simply added the library to its firmware (I do not know if it is properly licensed).
Keep in mind that there are two Meridian flips for a circumpolar object. One (the "normal one" when the target starts east of the meridian, and transits the meridian line between the pole and the local Zenith to the west of the meridian. The second one is when the target crosses the meridian from west to east along the meridian line between the pole and your local Nadir.
"Auto Meridian Flip" in ASIAIR is based on time and position of the mount.
To execute a Meridian flip properly on ASIAIR, these things need to happen:
1) before the meridian flip. both ASIAIR and the mount needs to think that the target is on the same side of the Meridian. This is done by very accurately modeling where the mount thinks its Meridian is. A 3-star sync will get you close. This is where plate solve and the "sync mount" comes into play. That "sync" tells the mount that it is not where it thinks it is pointed, but instead, it is pointed at the center of the solved plate.
Note that if a sync fails after a plate solve, all is lost, since the mount does not know where it is really pointed at.
2) at a proper time, a couple of minutes of time before ASIAIR thinks the target is about to reach the meridian, which occurs when the Right Ascension is equal to the Local Sidereal Time), ASIAIR stops guiding and tracking and wait for time to pass.
3) a few minutes of time after the Right Ascension of the target has passed the Local Sidereal Time, ASIAIR issues a GOTO to the target.
The two before and after times are user selectable times in ASIAIR guide settings.
Now, if the mount also thinks that the target coordinate has moved past zero Hour angle (or 12 hr Hour Angle for the second circumpolar meridian transit), the mount will execute a meridian flip by changing the other side to the instrumentation for a German mount, going through the pole.
ASIAIR uses a "after" plate solve (probably by using the camera angle from the plate solve) to discover if the mount has executed a flip. If not, it waits 60 seconds, and issue another GOTO, hoping that the mount will this time respond. Rinse and repeat.
For this scheme to work, the mount must know its correct hour angle. This will be natural to those who have been doing the hobby from before the electronic mount controls, where the first thing you do in an evening is to set the hour angle circle of the mount, to know where it is pointed at.
To get the correct hour angle, the mount needs a plate solve in step (2) above, to know how far it is from the Meridian. If that sync fails, you then depend on how accurately you have East-West leveled your mount. (Yes, ignore the lazy idiots who claim leveling is not needed -- this is where it is critical. It also helps decoupling altitude and azimuth adjustments during polar aligment.)
A "blind" GOTO (i.e., an unsync'ed mount) will miss a target by 1 hour in Right Ascension for each 15 degrees it is off East-West leveling.
I.e., if you are not leveled to within 15 degrees east-west, step (3) above can take 1 hour of time before the mount moves. This is true even if your mount has an absolute encoder.
That's 4 minutes of time for just 1 degree off east-west leveling. If you don't want to waste 4 minutes waiting, you must be within 1 degree of leveling.
If you refuse to level your mount, you must depend on plate solves and syncs so that the mount can know its real location.
Or simply wait 4 minutes times the number degrees the mount is not east-west level.
Why did I get *Sync Failure" when manually trying to plate solve?
Check with the mount's manufacturer if your mount requires some action (like a 3-star sync, for example) before it will accept a sync command in its command protocol.
A plate solve simply identifies the coordinates of the center of a plate. That coordinate needs to be set in the mount by using a sync command. If that sync command fails, then subsequent GOTO will also fail.
In your case, plate solve succeeded (i.e., exposure times, focus, etc are all functioning properly -- no need to waste time checking those). But sync failed -- and you need to find out from your mount's manufacturer why the sync failed. It may be simply because it needs a manual star alignment during initial setup.
If your mount is not capable of executing a sync command, simply follow what the mount documentation on how to perform visual star alignment.
Chen
