Moonlite focuser question


Odd problem started recently. Using My count range is approx. 9000 but when I turned it on a few weeks ago it showed 15305. I lowered it by uncoupling the stepper and it worked fine for a couple of sessions. Today I turned it on and it showed 10,000. How likely is it this is SGP-related? Other possibilities are ASCOM driver and hardware. Anyone seen this?



what i typically do i similar situations is uncouple of motor, rack the drawtube all the way in and set it to position 0 in the moonlite ascom driver before connecting to SGP. i know that my focus zone is 8500 so it easy to just tell the motor to go back to it using SGP.

just my two cents.


Probably pretty unrelated. We can’t sync a focuser, we can only move it. I also have a moonlite controller (the lite one with no interface box) and haven’t had this occur. Maybe if you have the one with physical buttons they’re somehow getting pressed when the unit is powered?

Also if this happens you can go into the Moonlite ASCOM settings and sync the focuser to whatever position you want. That might at least get you close enough without having to decouple the motor.



This is what I have been doing. My close-focus are is around 5000 counts out of around 8800. I was just wondering why it was occurring. Thought it could be a controller malfunction or ASCOM issue.


I have the one with buttons. I will check out ASCOM. It would be easier to manually adjust the count than run the focuser all the way out and back to zero. The last time this issue occurred I noticed the focuser was completely pulled in to minimum against the stop though the reading was 10,000.



I have not yet managed to run a sequence with my new moonlite , keep getting “Error in Auto Focus” current focuser. Current focuser position does not support required range. Currently at 16 needs to move in by 30.

Now using latest software upgraded yesterday, also got same message when using previous software?

Confused newbie.


We would need logs. But to me it sounds like you may be at one of the limits of travel. I use a moonlite focuser and it works great with SGP.



I have just gone through a set up again and I increased the binning to 2x2 in the Focus control settings and things seem to be OK now, no warnings are popping up…update, it works then stops, I have yet to run a sequence so have no logs.that I can locate.


i missed this thread when it was originally posted. i have 2 moonlite controllers, one of which would exhibit some strange behavior as described by the OP - the focuser position as reported by the driver would sometimes jump to the max or the min in the middle of a run… i sent that controller back to Ron and he sent me a new one, but i’m not 100% convinced it was the controller hardware that’s bad. it seems like this only happens to me when using certain USB and/or power configurations, but i’ve never gotten to the bottom of it. at any rate the 2 that i’m using now seem to be less susceptible to the problem.

i do know that in the particular configuration i’ve got going now, on cold boot the focuser controller does not respond to the first command sent to it. however, after that first command it does wake up and start interacting with the computer. so there could be some bugs in the AVR programming in the controller, or maybe it’s USB enumeration related… just not sure.


I think I have managed to get the focuser talking and to run, Weighted Average 1593:HFR .3.49. I still cannot get a sequence to start:o( ???sg_logfile_20180204185132.txt (552.3 KB)
sg_logfile_20180204201039.txt (188.2 KB)

If this carries on will have to join the Foreign Legion to .,forget…astrophotography !!!

Camera. ZWOASI 017mc CEM60 mount. lodestar X2 WOFLT132, Windows 7

Thanks Steve


The error seems to be the same as you originally posted, SGP is trying to move the focuser to a negative position. That’s not possible so the focuser is sending an error. On the MoonLite the zero position should be with the focuser racked fully in to the stop. I don’t know where yours is but that’s where SGP thinks it is.

The DRO controller should show the position on it’s display. Also the ASCOM log would help to show what is happening from the focuser’s point of view.


I’d only looked at the first log file. The second shows correct operation with the focus position set away from zero and a series of auto focus runs, then everything is closed down n what looks like an orderly manner. There doesn’t seems to be anything obvious going wrong.


Thanks Chris.