GSS (Green Swamp Server) alternative to EQMOD

[david_taurus83]

Been looking at doing a PPEC on my AZEQ6 but see conflicting posts on a few forums that say the EQMOD AutoPEC may cause conflicts with PHD and dithering. So decided to give GSS a go. Wow! It's like having a different mount! Heres a shot of the mounts typical PE as measurements by the guiding assistant. Almost 40" peak to peak which is about right for these.

 

So i done a PEC training session on GSS and enabled it once complete. I noticed an almost instant improvement in guiding which was hovering around 0.6/0.7RMS without PPEC. This is typical of this mount on most nights but there's a lot corrections being applied and peak to peak can be around +2/-2. After enabling I noticed straight away the flatter graph and tighter target grouping. Decided to run guiding assistant again to see how the PEC application was working out.

Masive improvement. Theres a steady drift over 2 worm periods so the figure is doubled in the above pic but it went from around 30" down to under 8" over one cycle with the GSS PPEC applied. I let it guide for a while after this to try and get a picture of the stats which were around the 0.4"RMS mark, sometimes into 0.3's but of course a band of clouds moved in and messed that up. 

Another nifty trick GSS has is the ability to force a pier flip (near meridian flip on command). I calibrated near 0° and moved  to a star (3 Orionis) that had just passed meridian prior to running the guiding assistant. I forced a flip and was surprised to find it was very close to centre in one swoop. Very close. Within arc seconds. To test it wasn't a fluke after I finished with PHD I sent a goto command to slew to M81. It slewed from more or less due south right round to M81 and got it centre frame in one go, no platesolving or syncing. I've never had that with EQMOD. Would be 2, maybe 3 movements and syncs to get on target. Hopefully it's not a fluke and is repeatable next time out but GSS is looking very promising.

 

Edited February 12, 2022 by david_taurus83

[Adreneline]

Thanks for posting this David - very interesting especially as I have just bought an AZEQ6 and just installed NINA with a view to maybe trying it out. I’ve been doing AP for five-plus years and never heard of GSS before. I might need to give this a go!

I would be interested to hear how you get on.

Adrian

[scotty38]

I use this too. I tried it once before and gave up as I had issues with flips not happening. Tried again and set the limit to 0 and now NINA controls it just fine and flips work perfectly.

[Stuart1971]

You would have gotten the same Improvement with EQMOD PEC, it doesn’t interfere with PHD2, as long as you don’t use the `PHD2 built in PEC algorithm…at that same time, that’s when you have issues….

GS, is ok, but it does nothing for me that EQMOD does not, and it can be buggy too…

[malc-c]

I tried GSS too, but as I use a modified HEQ5 with a 4:1 gear ratio owing to the original developments of belt driving the thing in 2011 needed the developers to offer this option.  They tried, but in testing things went astray and I nearly damaged my mount so I gave up and went back to EQMOD, which already had the offsets needed built in.

You have to think on that EQMOD has been around for around 15 years now... and was originally developed to control just two mounts, the HEQ5 and EQ6.  It's been developed over the years, but is somewhat dated.  GSS was originally written to take advantage of features found in the EQ8 and provide functionality for the EQ8 that EQMOD lacked.  It too has since been developed and now supports more and more mounts.  Like Stuart, EQMOD does everything I need, and with my mount I have little choice but to stick with it.

[Stuart1971]

Well, I actually have the EQ8, and because of that I tried GSS, but the only really difference for this mount, is that in GSS you can perform an Autohome, which you can’t in EQMOD, and that was not really an issue, there were other things that just worked better in EQMOD, so stuck with it…

As far as PEC is concerned, there is no difference between the two for this, as at the end of the day they should be the same as the PEC on the mount is not going to change it’s just the way the different softwares record it that will probably vary, can you then record the PEC curve into the motor controller with GSS, so it’s there all the time…?? I would assume so,  it I don’t know, this can be done with EQMOD and is very useful….

[david_taurus83]

27 minutes ago, Stuart1971 said:

You would have gotten the same Improvement with EQMOD PEC, it doesn’t interfere with PHD2, as long as you don’t use the `PHD2 built in PEC algorithm…at that same time, that’s when you have issues….

GS, is ok, but it does nothing for me that EQMOD does not, and it can be buggy too…

Perhaps, but the single slew pointing accuracy I experienced last night? No chance with EQMOD. As @malc-c points out above, EQMOD was developed for 2 mounts and I've long suspected if the generic HEQ5/EQ6 driver was correct for the newer range of SW mounts like the EQ6R and AZEQ6. GSS is still being developed with the latest version only released last December. It correctly detects my mount as an AZEQ6 with correct gearing ratios etc. It's my first time trying it so can't comment on any bugs yet but my first impression is very positive. 

[david_taurus83]

22 minutes ago, Stuart1971 said:

 can you then record the PEC curve into the motor controller with GSS, so it’s there all the time…?? I would assume so,  it I don’t know, this can be done with EQMOD and is very useful….

I believe it does as the light on the mount started flashing when I done it. 

[scotty38]

I use various park positions, the 3D view is handy plus the interface is just nicer. Could I do all that in eqmod, well yes apart from the 3D bit so really just my preference. No bugs found either, works great.

[Stuart1971]

42 minutes ago, david_taurus83 said:

I believe it does as the light on the mount started flashing when I done it. 

The lights flash to indicate that PEC is being recorded, but not to the mount, that’s a separate thing…👍🏼

[david_taurus83]

I've just found out that GSS only does PPEC with compatible mounts so yes, it is save to the mount.

[malc-c]

The good thing is that both EQMOD and GSServer have an active support group and the original developers are still able to provide input

[Jonny_H]

Whilst on the topic - I too am trying out GS Server as I have very recently moved to NINA so feeling my way around at the moment.

In the fear of this being a daft question - do you need to retrieve coordinates under the observatory location section of GSS? If so I cannot seem to get mine to retrieve as i keep getting an error. Not sure if this is relevant though as everything I have read/watched - no one really talks about this section and just seem to say that they have already synced.

[scotty38]

21 minutes ago, Jonny_H said:

Whilst on the topic - I too am trying out GS Server as I have very recently moved to NINA so feeling my way around at the moment.

In the fear of this being a daft question - do you need to retrieve coordinates under the observatory location section of GSS? If so I cannot seem to get mine to retrieve as i keep getting an error. Not sure if this is relevant though as everything I have read/watched - no one really talks about this section and just seem to say that they have already synced.

I think if you have a GPS of some description you can click the button and retrieve. I think I entered mine manually and again I "think" CDC will just retrieve coordinates for slewing depending what has been selected in the app but can test later if needed.

[Jonny_H]

3 minutes ago, scotty38 said:

I think if you have a GPS of some description you can click the button and retrieve. I think I entered mine manually and again I "think" CDC will just retrieve coordinates for slewing depending what has been selected in the app but can test later if needed.

Thank you for this.

Rightly or wrongly I had assumed that the coordinated would be pulled through GSS or one of the other pieces of software in the chain, e.g. via the Internet. But it makes sense that you need a GPS device for this.

Lessons learned......never assume

[david_taurus83]

I just enter the coords manually into every software including NINA. If there's a slight difference though NINA does ask if you want to import the mount coords (EQMOD or GSS or on mount GPS) to NINA or export NINA to mount. I always chose mount to NINA.

[david_taurus83]

Great guiding tonight. I haven't touched the mount. Simply switched from EQMod to GSS and PEC train. Also, the pointing accuracy is spot on. Slewed from home position to target and was within 52 pixels without platesolving. Meridian flips with NINA also work flawlessly.

I will echo my comment at the top, its like having a different mount.

 

[david_taurus83]

Another night with GSS and pointing and guiding is spot on.

 

[Stuart1971]

37 minutes ago, david_taurus83 said:

Another night with GSS and pointing and guiding is spot on.

 

I have also swapped to GSS after a few issues last week with EQMOD, thought I would give it a try, so all set up waiting for a clear night….👍🏼

[Stuart1971]

Well I have to say GSS seemed to work well tonight after first light with it…guiding was better but only after using PPEC, but much easier to do with GSS I have to say…

Still getting some oscillation in R.A., so not sure if my AG setting is too high…

 

[david_taurus83]

11 hours ago, Stuart1971 said:

Well I have to say GSS seemed to work well tonight after first light with it…guiding was better but only after using PPEC, but much easier to do with GSS I have to say…

Still getting some oscillation in R.A., so not sure if my AG setting is too high…

 

How did you find it's accuracy when slewing to target? I can do a meridian flip and without solving it will be back on target within 100 pixels or so. 

[Stuart1971]

3 hours ago, david_taurus83 said:

How did you find it's accuracy when slewing to target? I can do a meridian flip and without solving it will be back on target within 100 pixels or so. 

Spot on, about the same as with EQMOD, but the settings are just easier to use in GSS, the GUI is better, PEC in EQMOD was a nightmare to use, but in GSS it’s a doddle, although I would have thought it would use more than 1 turn of the worm to get the PEC, as 3 or 4 would give a much better average…but it worked well, I was very happy with it..👍🏼

[Stuart1971]

Well, after another great session with GSS, I may well be sticking with this…best guiding ever, never went above 0.5 rms, all night, and the best was under 3.0 rms…well happy..

I did have one instance where GSS crashed, but it was while I was messing with the 3D picture, and it crashed, this has been reported and could be an issue when using over windows Remote Desktop, as I do, so I have now turned the 3D plot image off, then it ran all night fine….👍🏼

 

Edited March 19, 2022 by Stuart1971

[scotty38]

Nice guiding! Best snapshot I saw and managed to capture last night was 0.39 🙂 🙂 I was 0.58 for the entire run which I am happy with for the AZ-EQ6

[david_taurus83]

I also had it down below 0.3" for a spell the other night. Generally speaking, looking through the guide logs, the average all night is below 0.5".