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MaxDome II automation dome tracking question

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#1 robininni

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Posted 05 May 2013 - 10:22 PM

I have my telescope set up on an Orion Altas and Maxdome II automation used with my exploradome. The scope is tracked very well by the dome EXCEPT slightly west of south. When I slew to an object there, the dome is not accurate but I think it would be accurate IF the telescope had done a meridian flip. However... it isn't time for the meridian flip apparently because my Orion Atlas doesn't do it for that particular object.

If I slew away from this 'danger' area, the dome will again track to the correct location for the scope.

Any idea what is going on or how to fix it?

It's like the Ascome Dome Control thinks a meridian flip should have occured but yet it didn't.

On a side note, how can I force my Atlas mount to make a meridian flip early? It wants to wait til the last minute :) and sometimes I would like to leave the observatory and I could if I could get it to flip early. I've read something about adjusting the time, but then it won't point accurately, right?

Thanks for your help.

Rob

#2 Christopher Erickson

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Posted 06 May 2013 - 01:14 PM

It sounds like a problem in the ASCOM driver for your particular mount. Hopefully just a configuration problem. I see this when generic LX200 or Celestron emulation modes are used instead of specific mount drivers.

One potential solution is to force a meridian flip by slewing to an object farther over on the other side of the meridian, forcing a flip and then slewing back to the target object. The mount shouldn't flip back so you should be okay.

#3 robininni

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Posted 06 May 2013 - 01:21 PM

It sounds like a problem in the ASCOM driver for your particular mount. Hopefully just a configuration problem. I see this when generic LX200 or Celestron emulation modes are used instead of specific mount drivers.

One potential solution is to force a meridian flip by slewing to an object farther over on the other side of the meridian, forcing a flip and then slewing back to the target object. The mount shouldn't flip back so you should be okay.


Thanks for chiming in. I do use a 'generic' driver since the Atlas mount doesn't have its own. Orion instructs us to use the Celestron Driver.

If I do make the mount meridian flip by having it slew to a target farther over guaranteeing a flip (which I have done), if I then have it slew back to the previous target it will simply meridian flip back during the process.

I have tried this several times, not related to this issue, but when I wanted to be able to go back inside my house but the mount was close to needing to be flipped, if I selected a new target further over requiring it to meridian flip, and then I selected the target again that I really was interested in, it would meridian flip right back to how it was. The Altas mount seems to wait till the last minute to be okay with a meridian flip.

Any ideas?

Thanks,

Rob

#4 Christopher Erickson

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Posted 06 May 2013 - 05:10 PM

It sounds like a problem in the ASCOM driver for your particular mount. Hopefully just a configuration problem. I see this when generic LX200 or Celestron emulation modes are used instead of specific mount drivers.

One potential solution is to force a meridian flip by slewing to an object farther over on the other side of the meridian, forcing a flip and then slewing back to the target object. The mount shouldn't flip back so you should be okay.


Thanks for chiming in. I do use a 'generic' driver since the Atlas mount doesn't have its own. Orion instructs us to use the Celestron Driver.

If I do make the mount meridian flip by having it slew to a target farther over guaranteeing a flip (which I have done), if I then have it slew back to the previous target it will simply meridian flip back during the process.

I have tried this several times, not related to this issue, but when I wanted to be able to go back inside my house but the mount was close to needing to be flipped, if I selected a new target further over requiring it to meridian flip, and then I selected the target again that I really was interested in, it would meridian flip right back to how it was. The Altas mount seems to wait till the last minute to be okay with a meridian flip.

Any ideas?

Thanks,

Rob


That is going to be a tougher nut to crack. The Orion (Synta) Synscan GOTO system is a clone of an old Celestron GOTO system that is no longer being made. That all happened before Synta bought Celestron. The fact that the Synscan meridian flip decision is different than what the Celestron ASCOM driver expects might be unresolvable without the help of the programmer that wrote the Celestron ASCOM driver.

Are you using the latest version of ASCOM and the Celestron ASCOM driver?

Chris Rowland (email addy removed) is the programmer for the Celestron ASCOM driver and probably the best person to answer deep, meaty questions about it.

I hope this helps.

#5 BPO

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Posted 06 May 2013 - 07:52 PM

Hi Rob.

Have you tried the EQ6, EQMOD and MaxDome Yahoo! Groups? That's where the experts hang out.

#6 Christopher Erickson

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Posted 06 May 2013 - 11:05 PM

Okay, I downloaded the latest Celestron ASCOM driver and have studied the driver setup parameters and support documents.

It appears that the Celestron driver queries the mount's RA/DEC and Alt/AZ coordinates to determine which side of the meridian the mount is on. There are no user-configurable parameters related to meridian flip.

Given this information I believe your only solution is going to be to play with different scope models under the Celestron driver or/and to contact the driver's author (Chris Rowland) about what you are seeing.

And make sure you are using the latest version of the driver.

#7 cn register 5

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Posted 07 May 2013 - 01:52 AM

Chris Rowland here...

I've heard that the Synta controllers use the Celestron ASCOM drivers, but didn't know about the Orion Atlas. They operate an older version of the Celestron protocol, about the same as the Celestron version 2.2 for the GPS scopes.

The ASCOM driver has a SideOfPier property and for the older mounts this is calculated using the hour angle and assumes the flip depends on which side of the meridian the scope is pointing. If the scope is actually tracking past the meridian then this will not be allowed for. If the diver thinks the scope is a fork mount then the side of pier won't be calculated at all. I don't know which of these apply.

I've no real idea what the Synta scopes do and don't have one so can't test, especially for detail such as the side of pier performance.

Finally, I'd appreciate it if people didn't post my email address in clear on the web, I get enough spam thank you. My address is available in the driver help.

Chris

#8 Christopher Erickson

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Posted 07 May 2013 - 02:29 AM

Chris Rowland here...

I've heard that the Synta controllers use the Celestron ASCOM drivers, but didn't know about the Orion Atlas. They operate an older version of the Celestron protocol, about the same as the Celestron version 2.2 for the GPS scopes.

The ASCOM driver has a SideOfPier property and for the older mounts this is calculated using the hour angle and assumes the flip depends on which side of the meridian the scope is pointing. If the scope is actually tracking past the meridian then this will not be allowed for. If the diver thinks the scope is a fork mount then the side of pier won't be calculated at all. I don't know which of these apply.

I've no real idea what the Synta scopes do and don't have one so can't test, especially for detail such as the side of pier performance.

Finally, I'd appreciate it if people didn't post my email address in clear on the web, I get enough spam thank you. My address is available in the driver help.

Chris


My apologies for your email addy in the post. I have removed it. Since it was already openly posted "in the wild" I assumed that it wouldn't be a problem.

At any rate it sounds like you are unable to provide much help for the OP's meridian flip problem, which is unfortunate.

#9 robininni

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Posted 07 May 2013 - 07:00 AM

Thanks Chris Erikson for really digging into it for me. Thank you others too, for your contributions. I'll just keep working with it. I know Orion says I can choose the scope as either “Celestron NexStar 5i” or “Celestron 8/9/11 GPS”. I will try the GPS version and see if it still has the problem.

Rob

#10 cn register 5

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Posted 07 May 2013 - 02:40 PM

You may do better selecting the Synta Mount in the Celestron driver. This will set the mount type to GEM and may match the mount type better than the Clestron mounts, all of which are fork mounts and so don't implement the side of pier correctly for a GEM.

Chris

#11 robininni

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Posted 07 May 2013 - 03:13 PM

You may do better selecting the Synta Mount in the Celestron driver. This will set the mount type to GEM and may match the mount type better than the Clestron mounts, all of which are fork mounts and so don't implement the side of pier correctly for a GEM.

Chris


Okay, thanks, I will try that. I didn't know there was a Synta choice but what you say makes sense. When selecting Nexstar 5i, I am able to choose GEM mount so the ASCOM program **should** know that I am not fork mounted so I don't think that is the issue.

I got a reply from Rich at Orion who said that the Altas mount tracks past meridian so it will only meridian flip once it is past the meridian.

With this information, I am thinking that the issue is the Celestron choice "Nexstar 5i" makes the software think of a mount that flips before the meridian and this is the difference causing me grief?

More experimentation and hopefully I will resolve this.

Rob

#12 robininni

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Posted 07 May 2013 - 10:00 PM

I seemed to have solved the problem. I tried the GPS scopes like Orion suggested in the manual (it was supposed to work with those or the Nexstar 5i which I know ends up giving my dome false info for that little section of sky west of the Meridian) and I got terrible results as far as where the dome thought the scope was.

Since I had nothing to loose I decided to just start trying other Celestron scopes and I started with the CGE/CGE PRO 1100. Bingo! That one worked and as far as I tested the dome now correctly follows the scope everywhere including that one section of the sky I was having trouble with.

Hope this may help someone else if they ever have an Orion Atlas (or maybe other Orion mount) and are trying to track the scope with Ascom Dome Control.

Rob

#13 cn register 5

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Posted 08 May 2013 - 02:09 AM

Thanks for the feedback Rob, good to hear that its working.

What's happening is that the scope type selection determines if the mount is a fork or GEM and this makes a difference to the side of pier reporting.

Did you try the Synta mount option? That should also set the mount type to GEM.

Chris

#14 robininni

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Posted 08 May 2013 - 08:39 AM

Thanks for the feedback Rob, good to hear that its working.

What's happening is that the scope type selection determines if the mount is a fork or GEM and this makes a difference to the side of pier reporting.

Did you try the Synta mount option? That should also set the mount type to GEM.

Chris


Chris, while I understand the CPC mounts are alt az ( I don't know what the Nexstar 5i is), the dome control does have a specific check box to mark the mount as GEM. Apparently this isn't enough. The dome tracked well using 5i and marking it as GEM except in that one section of the sky where it clearly thought the mount had flipped when it hadn't yet.

I never tried the Synta mount since I found the CGE / CGE Pro 1100 worked before I got down the list to the Synta.

One other thing I have to contact Orion back about is that they told me the mount will track past meridian (true), but that once past meridian, a new slew to the same object will flip the mount and this was not the case until it was WAY past the meridian. I would like to know exactly how far past meridian it will allow a flip.

Rob

#15 dmahon

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Posted 05 August 2013 - 09:20 AM

Wouldn't you be far better off ditching the Celestron driver and using the absoluetly excellent EQMOD with your Orion Atlas instead?






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