Unable to connect to mount



NCSF club Celestron CGM Pro mount

Orion Starshooter guide camera

ZWO 1600MM camera with LRGB filters

Software Background:

Windows 10 (not updated for a month or more as I have turned off automatic updates so they would not attempt to update while out imaging)

SGP version

Ascom Profile Explorer version

Ascom Diagnostic Properties (have not “Run compatibility troubleshooter”)


Celestron mount owned by the club (I have no idea if it needs an update or can be updated)


  1. SGP (for the second time in 2 months - like my last New Moon session in November) told me that it would not connect to the telescope mount - “unable to connect to Celestron driver”. The camera did connect.

A member from another club had mentioned last month that I change the power settings on the USB ports and I did disabled all of them. But that evidently did not fix the problem.

After 4 hours of trying through multiple reboots and new SGP attempts to connect all equipment, SGP and the mount finally connected and then surprisingly with every reboot thereafter (because of the other problems mentioned below) SGP subsequently always connected. But after all of those reboots, I still do not understand what prevented SGP and the Celestron mount/driver from connecting over hours of many attempts and then what allowed them to ultimately connect Friday night and last month.

  1. After all equipment finally connected, I then went to Frame & Focus and everything was tack sharp Friday night. However, Frame & Focus just kept showing a scrolling “downloading” but never showed me an image. Then that somehow finally corrected itself during one of my ultimate reboots of SGP. Again, I have no idea why it was not working and then ultimately did.

  2. Each time SGP plate solved successfully but when it came time to PhD, the guide camera power light kept shutting off and I recall getting an E22 error message and an E6 error message. There was also one other error message but I don’t remember that number. Numerous times I would unplug and plug back in the end of the USB attachment to the camera. Again, I have no idea why after connecting all equipment successfully the guide camera would power down. I do not believe there is any software for the guide camera that could be causing that problem - correct? Then after trying again and again I was finally able to get PhD to start guiding.

  3. SGP finally started taking an image and went through an entire 3 minutes session but when it came to downloading, it again scrolled the downloading message just like it did with Frame & Focus while never actually downloading the picture nor showing me the completed image. After about the 4th reboot just for this issue, SGP actually started to acquire and save images. But then it was 11 p.m. so I lost a good 5 to 6 hours of Imaging and particularly over the darkest part of the sky.

I put in a 12 hour night which for only 4 hours of data. This problem of connectivity has happened twice now in the last 2 outings. Totally disgusted!


I’d recommend attempting to work out these connectivity issues during the day vs trying to get them figured out at night. A lot of things with SGP can either be simulated though the ASCOM simulators or tested during the day vs wasting clear nights. It very well may be worth updating the firmware as well as the ASCOM drivers for the mount. Also is over a year old now, I’d also recommend updating to the latest SGP2.



Thank you Jared. I will update both Ascom and SGP but if it were totally software, why does it ultimately connect after many hours of trying?

Also, what firmware are you suggesting being updated?


Jared - might I hear back from you on my questions - especially about firmware. Thank you.


I’m not sure. Maybe multiple attempts eventually put it into a state that the connection succeeds?

The firmware for the mount. Depending on how old it is it could be a compatibility issue between the mount firmware and the ASCOM driver.



I spoke to Celestron and the first person I spoke to did not know of any firmware to update but they were sending it up the chain in Technical further.

  Also - please tell me more about ASCOM simulators.  Not familiar with that or those.


However, doing a quick google search and I see the following:

  Our club bought this mount used so I do not know what firmware has been updated and will also have to check what hand controller is used.  The hand controller we use has an telephone connection plug below that requires a serial bus (I believe a RS-232 cable).


Jared, it just struck me that if I update SGP from my current version to, I am fearful of losing all my settings if a new version is installed. Since someone else (who isn’t available anymore) put in all the telescope, autoguider and camera settings in SGP for me, I cannot risk losing them with an update.



The mount and hand control firmware versions are readable from the hand control, usually in the Utilities section.
The Celestron driver version may also be useful.
This looks like intermittent connection issues, USB, its connectors and cables aren’t the most reliable thing.
Is there an expert in your club who is familiar with your club’s equipment?


Unfortunately no expertise. Only 2 of us into astroimaging and use of the celestron mount.


Just an idea, but what part of the world are you located? Maybe if someone with the necessary expertise might be close maybe be able to stop in to physically see what is going on. Things like these are hard to troubleshoot over a forum.



Just checking to confirm whether updating SGP from to will lose all of my inputted settings.


No, you shouldn’t lose anything. If you’re that concerned about that you can backup all of your profiles as well. You can find them at C:\Users\%Username%\AppData\Local\SequenceGenerator they’re the .sgp files.



Thank you - that is helpful.


Two follow-ups Jared.

  1) When I open up SGP at home without any equipment connected, I have been recently receiving the following message:

  When I scroll down under Details,  There is the following message:

(see attached)

Should I do anything with these warnings or can I hit Quit?

2)When discussing my failure to connect with the mount issue with a member at another astronomy club and then discussing software updates, one member also mentioned possibly downloading Astometry.net.local.
  Is that download really necessary if one is using PlateSolve 2 which the fellow had installed on my computer when setting up SGP?  Basically, my procedure when I am able to connect all equipment is to go to Stellarium, copy the coordinates of the object; past those coordinates in SGP and then hit "Slew Now" and then later after frame and focus, "Center Now".   I have never used the Framing Wizard.

Thank you Jared for all of your time and insight>


1/11/2019 9:19 AM, Nolan wrote:


Just also received this message when checking on updates under SGP Help:

A* n error occurred while connecting to the server. Object reference not set to an instance of an object.*

  However, I just updated to SGP thinking the latest greatest might help me with my connection problems.  When I now click on updates, I did not receive the error message above.

  Note: I see  trial version 45 days remaining at the top of the page.  I assume that means that at some point I have to pay more dollars for what I just upgraded?



Jared - I updated all my software and went out to check my connections at the club observatory during the day. It connected to the Celestron driver!! (at least this time).

In the process of checking my settings, I noticed under “Starting Parameters” under “Settings” of PlateSolve2, the “arcminutes” are listed as 144 x 109 for the profile of both the club’s AT65EDQ telescope (420mm Focal Length) and the Explore Scientific 127 (952mm Focal Length). Is that a problem?

Another fellow set up SGP for me and he is no longer around. No one else I know who uses SGP can tell me how they calculated that number either. I have looked at the Help screen and online but do not seem to find an answer.

Thank you.



Probably not. SGP will calculate these values out based on what you have set in the camera settings and will
send this over.

Glad it sounds like things are finally staring to work out!

SGP3 is an upgrade (with additional cost) to SGP2. If it’s a club scope and setup you may ask them if they have an account for SGP2 and if they’ll cover the upgrade.



That’s a relief. Thanks Jared!