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odd CGEM/ASCOM/TheSky behavior

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#1 ssouza

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Posted 12 April 2010 - 10:36 AM

I had our CGEM/ASCOM/TheSky combination (hand controller rev. 4.15) working well until a power outage. Now after a two-star alignment I can control the mount through the hand controller just fine, but TheSky thinks it is pointing far below the horizon (which it is not). The hand controller reports (using menu>utilities>get alt-az) an altitude of, say, 290 degrees, when the telescope is actually pointing ~70 degrees above the horizon. I am using a tandem bar, and properly setting the OTA orientation to "West." Any ideas?

Steve Souza
Williams College

#2 jrcrilly

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Posted 12 April 2010 - 10:47 AM

Any ideas?

Steve Souza
Williams College


Make sure that TheSky is using the correct date/time/location info.

#3 Tapio

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Posted 12 April 2010 - 10:56 AM

Do you park the scope in the end of a session ?
Where does the Sky point (ie the scope) when you start a session ? Near Polaris ?
Altitude can't be 290 degrees, that must be azimuth.
I think you should park the mount and then set your tandem bar so that scopes are pointing at Polaris.

#4 ssouza

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Posted 12 April 2010 - 10:57 AM

Triple-checked the site and time/date info in both TheSky and the hand controller, the ASCOM connection, and redid the alignment several times. I strongly suspect something with the CGEM hand controller, since even without connecting to TheSky the HC reports a nonsense value for the altitude, which could be interpreted as below the horizon. Despite this, pointing from the HC works fine.

Steve

#5 nik hodges

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Posted 12 April 2010 - 10:59 AM

why dont you just resync the sky on the correct position?

#6 ssouza

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Posted 12 April 2010 - 11:14 AM

The park position is taken out of the equation because I align the marks on the RA and DEC axes before each alignment. And yes "altitude can't be 290 degrees," but that's just what the hand controller is reporting (I checked it again), so I suspect this is a clue.

Steve

#7 Chris Rowland

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Posted 12 April 2010 - 11:20 AM

Try a factory reset on the HC and a realign. It's possible that the power outage corrupted the internal memory in the HC.

And compare the Ra and Dec values reported by the HC, not the Alt Az because these are what's used to get the position.

The altitude value can be high depending on the side of the pier the scope is on, on one side it's in the range +90 to 0 to -90 and on the other something like 360 to 180 to 90.

Chris

#8 ssouza

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Posted 12 April 2010 - 12:06 PM

Try a factory reset on the HC and a realign. It's possible that the power outage corrupted the internal memory in the HC.

And compare the Ra and Dec values reported by the HC, not the Alt Az because these are what's used to get the position.

The altitude value can be high depending on the side of the pier the scope is on, on one side it's in the range +90 to 0 to -90 and on the other something like 360 to 180 to 90.

Chris

I'll try the factory reset, and then my next move is to update the HC firmware. I did not specifically compare the numerical RA/DEC between the HC and The Sky, but from the graphic display they do not agree.

Reporting "altitude" greater than 90 degrees on one side of the meridian is an odd software design choice, no?

Thanks,
Steve

#9 Chris Rowland

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Posted 12 April 2010 - 05:21 PM

Reporting "altitude" greater than 90 degrees on one side of the meridian is an odd software design choice, no?


Not at all, the "alt" and "azm" are reporting the true dec and hour angle axis positions and this is what happens with a GEM scope for the two pointing modes required for the two pier sides.

I've spent a lot of time with this, sorting out the SideOfPier property in the ASCOM driver, it does your head in :-)

Chris

#10 ssouza

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Posted 13 April 2010 - 10:29 AM

Last night I flashed the HC to version 4.16, and all is now well, so the power glitch must have scrambled something in the HC. Thanks to everyone for helping!

Steve






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