Did not park when requested, due to tracking turned off for safety

[datscope]

Bob

The following has happened twice that I know of. Last night was the latest:-

Pointing error is 0.214 arcmin @ angle 30.87
Image FWHM is 3.9 arcsec (2.60 pixels)
True focal length is 160.5 cm.
True image center (J2000): 15h 52m 48.6s 40 38' 09.80"
Imager sky position angle is 54.0 deg.
Image FWHM is 3.9 arcsec (2.60 pixels)
Within max error tolerance, no recenter needed
(turning tracking off for safety)
== Requested observatory shutdown ==
Parking scope.
**Script Error**
Source: ACP
Message: The script was aborted. at line 1771 column 13.

The plan requested shutdown, yet the telescope tracking was turned off for safety BEFORE the Shutdown at the end of the plan? It appears that the telescope would then not park when requested to.

I have not had time yet to do the script failed script and then park as we discussed a few weeks ago (too busy in work) so the dome closed at sunrise with the light sensor. So all ok and safe.

Any reason why the above would happen. A shutdown never used to do this? Has there been a change to the Shutdown script that I have missed?

I must get around to the script failed bit soon as that would have trapped this issue and parked anyway.

Cheers
Dave

[Dick Berg]

Hi Dave,

What were you expecting to have happen between these two log statements:

  Within max error tolerance, no recenter needed
  (turning tracking off for safety)

Could you post/reply with the plan.txt file and the .log file for this run. There are probably some clues there.

The message "(turning tracking off for safety}" is only found in one place in AcquireImages - line 1693 - and that is at the end of the plan. So it looks from the snippet of the log you provided, that the run had completed (image-wise at least).

The line 1771 is also in AcquireImages.js - that's where the shutdown routine is actually called from {"SUP.Shutdown"}. It's in SUP.Shutdown where the line "Parking scope" is logged. The next statement after that is the Park command.

I find that my scope (Meade) will move to the park position even if it's not tracking. So it looks like something went wrong right at this point.

You could test this by writing a plan with the single directive "#shutdown" in it. Then connect the camera and telescope, move the telescope to some place away from its parked position, turn off the tracking manually, and then run this test plan.

[Bob Denny]

Another possibility is that you have a scope that "disappears" (serial comms go dead) when parked. In this case, for roof safety, ACP waits for a full 2 minutes then assumes (without any real evidence) that the scope has parked. Next time wait for at least three minutes before assuming that it's broken. During this period, ACP will appear to be "dead" with no indicator light activity.

[datscope]

I have attached the plan and the ACP log

I expected the telescope to park when I put #shutdown at the end of the plan.

As I said before, it always used to park when requested to shutdown. It is only very recently that I have had this problem.

So what has changed? I did an ACP update a few weeks ago. Maybe somthing has changed that I dont know about? I am not aware that I have changed anything. I have been through ACP and Sitech and cannot spot anything that would change this.

As I said, my dome opens and closes normally from a slave switch on altitude. It will also close in bad weather or if the light sensor is tripped. This is hard wired and indipendant of ACP.

But, i really do need to solve this issue asit leaves theoptics exposed until sunrise at the moment.

I will try a #shutdown plan only as requested. If somebody could look at the simple plan and log that would be great.

Regards
Dave

[Bob Denny]

I see what you mean. it sat on Parking Scope for 4 hours. This would mean that (a) the driver never indicated that it started slewing the scope, or (b)O that the driver indicated that the scope was slewing "forever" and never stopped.

Can you think of anything that could have changed? The code inside of ACP certainly hasn't

I also note that you're having plate solving problems. Unless your pointing is really horrible (0.5 FOV or more) turn off the spiral search for starters, it's eating you alive time wise. I found several false solutions due to insufficient catalog stars, lots of image stars, and the repeated solving attempts during the spiral search. For example:

00:08:45   77 catalog stars found
00:08:45   Solved! 8 stars matched.
00:08:45   Average residual is 0.48 arcsec.
00:08:45   Pointing error is 11.106 arcmin @ angle 316.50
00:08:45   Image FWHM is 3.2 arcsec (2.04 pixels)
00:08:45   True focal length is 150.4 cm.
00:08:45   True image center (J2000): 16h 58m 07.2s   28° 00' 04.32"
00:08:45   Imager sky position angle is 59.3 deg.

Are you using the USNO catalog? I don't think so by the numbers of catalog stars listed. Switch to the USNO catalog.

Anyway, try to think of what may have changed in your telescope controller that might affect parking. ACP's code is pretty simple, it calls Telescope.Park() in the driver, waits for the driver to say that its slewing, then waits till it says it's no longer slewing... that's it.

[datscope]

HI Bob

No I am not using the USNO catalogue. I will try andsort that.

I do get pointing issues in different parts of the sky. Some areas are great no issues, others have problems. Maybe it isthe catalouge? I will let you know (when we get lear weather of course!)

I will swithc off spiral too.

Yes, I did have a Sitech issue not too long ago. But that system is working fine. It parks ok when using its park? I have looked through its configuration over the last week too, but nothing has changed in that as well?? So....I will check again and let you know if Ifind anything

Regards
Dave

[datscope]

Bob

I could not find anything in the help about loading the USNO A2.0 catalouge

Apparently it is superseded by USNO B1?

But how do I get the catalouge. I have search a number of sites and no luck? Any guidance would be a great help as I have not used anything else other than GSC

Yes my field is quite small even at F3 with the 20 inch (about 11 x 14 mins). So I guess a better catalogue is needed.

Will the USNO B1.0 or NOMAD internet section work? I guess I do not need to point the path reference to anywhere? Will this slow down the whole process?

Regards
Dave

[Bob Denny]

For plate solving the A2.0 is the right one. See Downloading and Using Reference Catalogs (a sticky note in the PinPoint section of the Comm Center here).

[Dick Berg]

HI Bob
I do get pointing issues in different parts of the sky. Some areas are great no issues, others have problems. Maybe it isthe catalouge?

Hi Dave,

Well, yes and no, it is the catalog and isn't. The catalog reflects the distribution and numbers of stars per square degree in the sky. The distribution of stars at a given magnitude across the sky is not uniform. You'll see many more stars in the directions along the Milky Way, and fewer stars in directions perpendicular to the galactic plane (away from the plane of the Milky Way). So the catalog mimics the way the stars are actually distributed in the sky. This will, therefore, create problems for guiding or for plate solving, all depending on where you're looking, as in the sparser areas of the sky.

The GSC goes down, maybe, to 12th magnitude. The USNO A2.0 catalog goes down to 19th, which is why it's a significantly larger catalog file than the GSC.

If you open the ACP Reference Guide (http://solo.dc3.com/ar/ACPRefGuide.html) and click on "Star Catalog Information," at the bottom of that screen is a link called: "Where can I get a copy of the <...> catalog?" and therein is a paragraph and link to the UNSO A2.0 catalog page. Here's the URL directly: ftp://ftp.nofs.navy.mil/usnoa/

This is a huge catalog (6,000 megabytes) but you can download it via ftp in bits and pieces at night if needed. Not recommended for dialup lines! Copy the readxxx.xxx files and the zonexxxx.acc and zonexxxx.cat files in this directory to a directory/folder on your system. All A2.0 files must be accessible and in one folder. In ACP, set your catalog type to USNO A2.0. Set your catalog path to the directory into which you copied the files from USNO. They will all be in one folder.

The USNO B1.0 is an even more huge catalog, only really accessible online. ACP can use it, but it means there will be a wait for an Interent connection, query, and data return online for each and every plate solve that's done. If that's infrequently in your case, it may be a good alternative. The USNO A2.0 is still an active and useful catalog to have on your computer.

[datscope]

HI Bob

OK I will look at that

I have found somthing that is odd.

When I tell the telescope to park in ACP from the menu bar, the Telescope text goes grey and does not do anything ACOP just sits there.

I have noticed that the Sitech controller immediately takes the drive to stopped. It used to say parking scope. I guess I need to speak to Dan. Or would any recent ACP update cause a comms issue to the drive?