Problem with PA on ASIAIR Plus

allen456

Last night was my first imaging run with ASIAIR Plus. When I first tried to Polar Align it got as far as taking the first image and rotating 60 degrees but then it just froze. I tried to wait it out but after 7 minutes I cancelled it and tried again. The second time it worked so I figured that I must have done something wrong the first time. Tonight the same thing happened again, only this time I couldn't get past it. I tried three times, same each time. When it started to rotate, the screen said 0 degrees and when it stopped it still said 0. The exposure button still had the black square in it. Anybody have any idea what I might be doing wrong? I using it with a CGX mount and and ASI294 camera. Yes I have the latest version of the firmware.

Kring

The same thing happens to me with my CGX as it’s not fully compatible with ASIAir. I was able to greatly reduce the frequency of this happening when I replaced the USB cable that runs from the AA+ to the Hand Controller with a heavy shielded one with the magnetic noise loop on the end. In my case I tried 5 different cables I had including the ZWO flat cable and they all acted strange. If you have a cheap cable that’s likely the culprit.

Even after this, I’ve learned to live with it and just be able to spot when it happens, it should flow quickly from shot 1, rotate, shot 2, calculate, next. If it doesn’t work in a matter of seconds you send the mount back to home via the mount settings inside the ASIAir app and start again. there’s no need to wait more than a few seconds after it stops.

If you get a failure again, give up and go manual, leave the HC disconnected and do PA, after picture 1, you undo the clutch and rotate roughly 60 degrees and tell ASIAir to take picture 2. After you are done, you will need to turn off the mount and follow the procedures for connecting CGX the first time (go to switches & set date/time on HC, connect to AA+, flip switch to connect, do quick align on HC)

It’s good to know these procedures to run PA again, I find it’s best to run through PA twice for accurate results. If you were far off from PA or took more than a minute to dial in PA, it’s likely there’s enough that’s happened that doing it a second time will either validate or expose slight inaccuracies in the first runs calculation

allen456

Kring ###
Thank you for your reply. Very useful info.

allen456

Kring I tried your suggestion but ran into a conundrum. How do I tell AA+ to take a second picture? After I have taken the first, I have to click Next. Then it tells the mount to rotate 60 degrees and the button to take a second picture has the black square and is disabled. All I can do is cancel. What am I missing?

I tried another cable (a better one, shielded) but it made no difference.

w7ay

allen456 After I have taken the first, I have to click Next.

To do manual rotation, you need to first unselect the mount from the Mount Setup window before starting the polar alignment process.

When you are done with polar alignment (which is simply to point your mount's polar axis to the pole), you can then reconnect the mount back, in able to use GOTO, slew and autoguiding.

Chen

allen456

w7ay I can do a manual rotation, that's no problem. The problem is taking the second image. The AA+ simply does not let me do that because the button is disabled. Do you know a way around that?

w7ay

allen456 The AA+ simply does not let me do that because the button is disabled. Do you know a way around that?

Is the ASIAIR Mount Setup still connected to your mount? It has to be disconnected for that Next button to be activated.

The procedure is this:

1) go to the Mount Settings window and disconnect the mount (the green slider toggle on the right).
2) select "PA" window.
3) tap on the big fat arrow on the right

ASIAIR will warn you that there is "Mount No Connection".

Tap on Skip, since you specifically don't want to connect to a mount!

ASIAIR will do a plate solve.

That is when the Next button should active. But don't tap on it until you have manually moved the RA by 45º to 70º.

If you do not see that button activate, then there is a some particular bug associated with your set up. You will need to wait for ZWO to answer you.

If the Next button shows up (if the plate solve succeeds), proceed with the instructions to correct altitude and azimuth errors, and when you are done, go back to the Mount Settings window to reconnect ASIAIR to your mount.

Chen

allen456

w7ay Thank you Chen. If it is clear enough I will try this tonight.

Kring

I think Chen covered it before me, I don’t have my scopes setup so can’t confirm. But I recall it being pretty straight forward; so it has me questioning if something changed in this most recent update.

One thought, just to confirm is the experimental feature under Info setting for Allstar polar alignment is disabled? It should be, I don’t know or think you can do manual PA with the experimental APA method.

w7ay

allen456 Thank you Chen. If it is clear enough I will try this tonight.

Oh, by the way, when you are done with manual polar alignment, it is a good idea to reset your mount to home position and repower the mount. Then do a simple star alignment if your mount requires it.

After that, reconnect the mount to ASIAIR.

The reason for this last step is that many mounts will loose the pier side information when you slew that 60 degrees (even with a computer directed slew).

If you find that the first GOTO after a polar alignment sends the mount to never-never land (you read about this all the time), your mount definitely needs this step. I have no idea why ASIAIR did not include it as an epilog of the polar alignment procedure.

Just remember to stay close to the telescope to catch any unintended behavior after a polar alignment, to catch it before something expensive hits the pier.

Good luck,
Chen

wvreeven

allen456 w7ay I use the PA routine of ASIAir all the time and I never reset the mount to home position nor do I power cycle it. The first GoTo is always nearly spot on and only a small correction is needed. No issues at all with pier side. I am using iOptron mounts (CEM25P, GEM28 and new GEM45) and all of them behave similarly well.
So it looks to me like PA issues are with certain mounts only and not with others. This is probably why ZWO did not include this as an epilog of the PA procedure. Plus, reading about PA sending the mount to never-never land "all the time" needs to be seen in context of the mount used. Once again, it NEVER EVER happens for my mounts.

w7ay

wvreeven Once again, it NEVER EVER happens for my mounts.

You probably missed the posts from people whose mounts went "south" after a polar alignment.

Eppur Si Muove.

Chen

wvreeven

w7ay You probably missed the posts from people whose mounts went "south" after a polar alignment.

No I didn't. And I never denied that this happens. However, that doesn't mean that it ALWAYS happens.

allen456

Well it appears that Chen is pretty spot on for my set-up with the CGX. I followed his procedure for manual PA and it went without a hitch. I did do a re-power of the mount and one-star align using the HBX after the PA but I found that the HBX is still active even when the mount is turned off. It appears that it gets sufficient power from the AA+ through the USB to hold and display its settings even with the mount off. I found I needed to unplug it. My only oddity was when I finished for the night. I sent the mount to home position using AA+ and it overshot the home by quite a bit. Apparently the was still a disconnect between the two devices.

Kring

@allen456 - ah yes, the dreaded USB powering the hand controller issue! That has hit me quite a few times with my CGX, all the reason ditching the HC, and going USB or WiFi with celestron mounts is a much needed move that can’t come soon enough. So yes, confirming you also have to disconnect the HC when turning off the mount.

I’ll add that the 1-star alignment is not necessary with the CGX, it wont get you anything. Doesn’t hurt, but also doesn’t add any value. A quick align works perfectly every time!

I have never had an overshoot before with my AA+ & CGX - has me wonder if the 1-star align is the issue. Just to confirm, when you start it back up after PA you are moving to switches? I assume yes, if so then follow the AA+ prompt to do the quick align. Right away, send to home and see if it overshoots.

w7ay

Kring ah yes, the dreaded USB powering the hand controller issue!

You can avoid the backpower by using this:

https://www.amazon.com/dp/B094FYL9QT

It only works at USB 2 speeds, which is sufficient for mounts.

I recently started a project to build a USB backpower preventor for the 9 pin USB 3.2 specs. The small circuit board is being fabricated at OSH Park as we speak. I am hoping it will allow me to use a greater selection of powered USB 3 Hubs with ASIAIR. Currently, I have only found one USB 3 hub model that works with ASIAIR. I have one hub that not only renders ASIAIR to be flakey over the night or as temperature drops (almost all powered hubs), but this one won't even allow ASIAIR to boot :-).

Chen