Meridian flip issues....sounds like it starts then immediately stalls

BArkin

I am having the above issues with SkyWatcher EQ3Pro mount. I have ensured Daylight Saving is turned off and that meridian flip is turned off on hand controller (however when i use the hand controller is not plugged into port due to set up.
I can see the count down to the flip occurring, but when it starts the motor makes a noise briefly (similar to when you turn it on and you can hear it engage) but the movement does not occur.

This is identical to the other issue I have read about on forums which is the need to turn to ASIair off after polar aligning as it wont move as instructed.

Can you please offer some support as to how to fix both of the issues please?

BArkin

PS all other functions work well and I have captured many images with this so far!

Tech@ZWO

Check whether the equatorial mount time and location information are accurate (including whether the daylight saving time is off)
Check whether the equatorial mount's Meridian behavior setting is 0 degree limit, and the behavior after reaching the limit is: stop tracking, not Meridian Flip.
Test the actual Meridian time of the equatorial mount: When the AIR prompts to start Meridian Flip, but the equatorial mount does not turn, you can try to use the hand controller to send the goto command to see when the equatorial mount flips. This time difference is calculated by the AIR and the mount Meridian . The time difference will always exist. You can set this time difference in Meridian Flip.

BArkin

As I’ve already mentioned I have checked points 1 and 2 have been checked already.

Regarding point 3 that’s been checked and is also fine.

The mount seems to do the same thing as the known fault with the ASI that occurs post PA completion. Eg. The mount doesn’t respond to the ASI after completing PA. the mount doesn’t seem to respond to instructions from the ASI when meridian flip timer hits zero. I can hear something engage, but it doesn’t move unless I restart the ASI.

Of course I can’t do this after meridian flip fault, as I would be asleep.

Any other ideas?

@tech@zwo#49474

Tech@ZWO

BArkin
Please upload log in APP->About->Feedback, and we will check.

pemongillo

For tech@zwo In detail, how do I do this? Test the actual Meridian time of the equatorial mount: When the AIR prompts to start Meridian Flip, but the equatorial mount does not turn, you can try to use the hand controller to send the goto command to see when the equatorial mount flips. This time difference is calculated by the AIR and the mount Meridian . The time difference will always exist. You can set this time difference in Meridian Flip. Also what is this? Please upload log in APP->About->Feedback, and we will check.

Kring

I ran into this the other night, in my case the mount was just physically past meridian, and AAP worked, after the countdown it issued a goto command, but my mount stayed, AAP had to do a few retries which all resulted in the same thing. If I did a goto from the HC, same thing happened! which means the mount isn't ready to flip just yet. I think this is due to a combination of two issues:

DST is not supported, being off an hour I think complicates things.. if DST would simply be supported and the local device time of AAP, mount time and iPhone time were all aligned, DST settings all the same, and Time zones all the same we would see a lot less of these meridian flip, goto and guiding issues.
AAP doesn't support flipping AFTER meridian, you can only flip before.. but my mount doesn't want to flip before a meridian, it wants to flip AFTER, even if you override settings via the HC, the AAP is still "asking" too soon. The AAP should change it's stop tracking and flip after times to allow for negative numbers...

To close out my story, I simply had to wait about 15min and then do a goto from the AAP and it worked, flip went fine and all was good, I just lost in total about 25 minutes of the best possible capture time. It's a matter of timing caused by a combination of the two issues above.

I don't have enough knowledge to figure out a workaround on how to trick the AAP/Mount to think it's later in the day. I believe it will require ZWO to fix the above two issues (or at least one of them)

The brief noise you hear on your mount is a successful goto message received by your mount from the AAP, but the mount says "yeah, I'm already here fool" and that bit of movement is the mount doing a recenter, the mount doesn't flip because it's still within it's limit of staying on the current side.

w7ay

Kring AAP doesn't support flipping AFTER meridian, you can only flip before.. but my mount doesn't want to flip before a meridian, it wants to flip AFTER

There are two parameters in the Meridian Flip Settings menu in the Telescope Setup window in ASIAIR.

The first one (Stop tracking x min before Meridian) is the time before when ASIAIR thinks Transit occurs. It is the time when ASIAIR will turn off image capture, autoguiding and tracking. Basically the hour angle of your mount (the "RA motor") should be frozen at that point, pointing just a little before meridian.

The second parameter (Do AMF x min after Meridian) tells ASIAIR how minutes after the transit ASIAIR should start sending GOTO commands to the mount.

Remember that ASIAIR does not perform Meridian flips. The ASIAIR simply sends a GOTO to the same target and depends on your mount to do a meridian flip when the target has reached the same side of the pier as your declination axis.

As such, you need to 1) tell the mount to not do anything automatic with meridian flips -- just make it wait for the ASIAIR commands, and 2) accurately star align the mount, or for mounts with encoders, make sure the mount is fully level in the east west direction. If you don't do step (2), the mount has no idea the target has transited even if time and longitude determines that the target has already passed the Meridian. For mounts with absolute encoders or mounts with relative encoders and homed to the index mark at the start of the evening, a east-west level of 1 degree will produce a disagreement of 4 minutes of time of transit. So, if you are 1 degree off level, ASIAIR will need to make GOTO attempts for at least 5 minutes.

If the mount's time is off by 1 hour, it will think that the transit has not yet occurred. Just check the mount's Local Sidereal Time (LST) with some program like SkySafari or LST apps on iOS.

If it is a DST problem, it will be over in two weeks.

Chen

Kring

The first one (Stop tracking x min before Meridian) is the time before when ASIAIR thinks Transit occurs. It is the time when ASIAIR will turn off image capture, autoguiding and tracking. Basically the hour angle of your mount (the "RA motor") should be frozen at that point, pointing just a little before meridian.

This is an issue, it should stop tracing x min AFTER the meridian! stoping before results in loss of caputres during
the prime seeing time

The second parameter (Do AMF x min after Meridian) tells ASIAIR how minutes after the transit ASIAIR should start sending GOTO commands to the mount.

You are correct, however this is pointless if it can't be aligned with stop tracking. Both of these settings don't work together, they should be collapsed into a single setting called "Perform Meridian Flip When" with a choice of plus or minus minutes of meridian transit time.

w7ay

Kring This is an issue, it should stop tracing x min AFTER the meridian!

Nope. The mount needs to stop tracking before it reaches the meridian so that no harm comes to any of the instrumentation placed on the mount.

The mount waits there until ASIAIR sends it a GOTO (after that second time event in the ASIAIR setup). At the second time event point, the mount will realize that the coordinate of the target has transited, and when a GOTO is performed, the motors will take the path of a meridian flip.

The choreography is very simple. x1 and x2 are the two Meridian Flip Settings that I had earlier described.

T-x1 : image capture stops, tracking stops, dither stops, autoguiding stops.
Clocks in ASIAIR and Mount keeps running.

T+0: Target crosses Meridian. Nothing happens.... we wait until T+x2.

T+x2: ASIAIR sends GOTO target.

Since Target has transited the mount will not execute a simple GOTO, but instead a Meridian Flipping GOTO. All German mounts do this.

Both of these settings don't work together, they should be collapsed into a single setting called "Perform Meridian Flip When" with a choice of plus or minus minutes of meridian transit time.

If you want this , set x1 and x2 both to zero. But I recommend against it since any small error in time, longitude, east-west mount level will cause problems. The reason x1 and x2 are allowed to be non zero is to get around problems.

Chen

stevesp

The meridian flip depends on the mount
Asiair sends just a goto
in Celestron you can set the goto behaviour around meridian in the mount parameters in hand controller
check the manual of your mount