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SynScan Firmware 3.36 Question

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#1 tclehman1969

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Posted 17 February 2015 - 01:36 AM

So, while trying to get over this nagging cold spent some time inside looking at the update and trying it out. Question I have is, what does it mean when controller after aligning the hand controller comes up with "Caution: Previous NPE applied". What is NPE? And should I be using the previous version or not? How do I not use previous NPE if not? 

 

It it also has something I think is new which is Cone Error. How do I set this? And also NP Error? 

 

Also, while I'm asking, the alignment procedure is for the goto for the mount not the actual polar alignment, right? 

 

Out of curiosity, for those that know, how accurate are goto's? I've always had issues with my goto's not being very good. Not setting something up just right! 

 

As an FYI, I have an Atlas Pro AZ/EQ.

 

 


Edited by tclehman1969, 17 February 2015 - 01:39 AM.


#2 rmollise

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Posted 17 February 2015 - 09:28 AM

I am not sure what it means either. I am sure you should not use 3.35 if that is what you are axing. It was indeed full of bugs and problems. Not completely non-functional, but it left me scratching my head on more than one evening. :lol:

 

I have had pretty good results with 3.36. It's still quite sensitive to alignment star choice from what I can tell, but seems to work well enough. :-)


Edited by rmollise, 17 February 2015 - 09:29 AM.


#3 HowardK

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Posted 17 February 2015 - 06:35 PM

So, while trying to get over this nagging cold spent some time inside looking at the update and trying it out. Question I have is, what does it mean when controller after aligning the hand controller comes up with "Caution: Previous NPE applied". What is NPE? And should I be using the previous version or not? How do I not use previous NPE if not? 

 

It it also has something I think is new which is Cone Error. How do I set this? And also NP Error? 

 

Also, while I'm asking, the alignment procedure is for the goto for the mount not the actual polar alignment, right? 

 

Out of curiosity, for those that know, how accurate are goto's? I've always had issues with my goto's not being very good. Not setting something up just right! 

 

As an FYI, I have an Atlas Pro AZ/EQ.

I am getting the NPE message after aligning in altaz with my 3.36 az eq6

no idea what it means...i ignore it

my gotos are good except at zenith where she fails completely and goes into a mad dance this way and that!


Edited by HowardK, 17 February 2015 - 06:36 PM.


#4 OzAndrewJ

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Posted 17 February 2015 - 06:53 PM

Gday All

I actually read the new manual last week after seeing this message :lol: 

NPE is "Non perpendicular error" and is used ( somehow ?? ) with CE "Cone error.

NPE is supposed to account for any errors in orthogonality between the RA and DEC axles,

Both CE and NPE can now be entered via the Hbx.

CE is supposed to be calculated and overwritten if you do a three star align but i have no idea how they measure NPE.

Maybe a third party app calcs it and you can enter it manually ????

I havent fully checked any of that yet as i am back in EQMod mode.

 

Andrew Johansen Melbourne Australia



#5 tclehman1969

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Posted 17 February 2015 - 08:42 PM

Yeah, I spent a good amount of time going through the manual and was finding nothing...then I realized I was looking at the wrong manual. Dang cold!

 

I did find the section on NPE and the cone error issue, but I can't figure out how you determine these numbers and enter into the hand controller. Or at least it seems to allow you to enter the number, or maybe just after a 3 star Alignmnet? I was fascinated to read in the manual a rather detailed description as to how to wedge a scope when putting it up on the mount in an attempt for the user to remove the error. 

 

One thing I did notice was that somehow after entering in location and running through an "alignment" - I was indoors, after all - I started going from one object to another, one item including Jupiter. Then suddenly, the mount started moving on its own and I just looked at it rather curiously. So, I picked up the controller, selected Jupiter again and it came back with Object below horizon! What? How did this happen. So, I looked at the information for my location and it somehow went from 122 west to 77 west and from 37 north to 37 south! How this happened, I have NO idea! So, I tried to park it, it parked in an odd place, turned off the mount, reset the home position, and started over. This problem hasn't re-occurred, but odd. Maybe my battery is low, but the hand controller showed it at 12.2 volts. 


Edited by tclehman1969, 17 February 2015 - 08:45 PM.


#6 HowardK

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Posted 18 February 2015 - 07:12 AM

Anyone got a link to the manual that mentions NPE and cone error?



#7 OzAndrewJ

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Posted 18 February 2015 - 03:11 PM

Gday Howard

 

http://www.skywatche...oads.php?cat=45

 

Andrew Johansen Melbourne Australia



#8 HowardK

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Posted 18 February 2015 - 04:40 PM

Thanks Andrew

 

seems you should set cone error and npe to zero in settings/alignment....this should stop the warning showing after alignment is done with.



#9 AgilityGuy

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Posted 14 December 2015 - 11:35 AM

Thanks very much for bringing this topic up.  I purchased a new Orion Atlas AZ/EQ-G mount in November and it came with a Synscan V4 handset.  Initialization routine for the handset only somewhat followed that described in the instruction booklet.  A number of steps weren't mentioned and I entered though them hoping they weren't critical.  One of them is the application of the previous NPE caution statement.  I didn't see it on the initial run through but when it appeared I figured it was calculated from the star alignments. No mention of it in the hardcopy booklet and didn't find it with a search of the pdf.  Since I wasn't sure what it meant I've have continued through it each time. Benign neglect on my part as the mount works well and I've gotten nice images off of it.  When the message came up again last night I figured I'd look a bit deeper and found this thread.  The Skywatcher V4 manual from the link provided by Andrew seems more complete and better written than the Orion counterpart.  Not sure if it will change how I'm approaching things but it's worth looking into.  At very least I have a better reference for the mount.   Thanks for the information and link!

 

JB



#10 wookie1965

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Posted 30 July 2016 - 05:23 AM

Hi,

           Has anyone found a fix for this I have just got an EQ5 Pro Goto and I`m having problems, the first time I used it after setting up per instructions objects were not central and the more objects I went to they drifted to the right out of view until finally were not in eyepiece at all. Second time used it did 2 star alignment and got "Caution Previous NPE Applied" was told to do a factory reset on handset did that then 3 star alignment worked pretty well not dead centre but could see objects. Took it out last night 2 star alignment same "Caution Previous NPE Applied" ignored that went to first 3 objects M13,M92, NGC 6210 dead centre next M10 and M12 over to right M16 not sure as it was only 11pm may have been to light but last M57 wasn't in eyepiece then the clouds rolled in. Any help much appreciated.



#11 jdupton

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Posted 30 July 2016 - 09:12 AM

wookie1965,

 

   If your only concern is the caution message, you can safely ignore it. It is completely normal. Below is my understanding of the message.

 

   When you do a three star alignment, the mount (HandBox, actually) tries to figure out three things: 1) the general orientation difference between where the mount's RA axis is pointed and the North Celestial Pole (the polar alignment error), 2) how much Cone Error you have (the degree of parallelism between the telescope's optical axis and the mount's RA axis), and 3) the Non-Perpendicularity Error (the amount by which the RA and DEC axes of the mount differ from exactly 90°). When you perform the three star alignment, the mount (HandBox) stores the calculated values for Cone Error and NPE in memory for future use.

 

   When you do a one star or two star alignment, the mount cannot figure out all of the above. It can only calculate the amount of polar alignment error based on the one or two stars you used. So, if you have previously done a three star alignment and for this session do a one or two star alignment, the mount simply recalls the data for CE and NPE from the values it stored from the last time you did a three star alignment. I does however warn you that it is using old data. That is the warning about "Previous NPE Applied".

 

   NPE doesn't normally change between sessions. With a good firm mounting of the scope to the mount saddle dovetail, CE can change a little from one observing session to the next but not by a lot each time. Thus it's perfectly valid to save and reuse CE and NPE from one session to another.

 

   If the cautionary message bothers you or you wish to refresh that data at the beginning of each session, just always do three star alignments. If you use different scopes on the mount, you should probably do a three star alignment anyway since that will refresh the stored value of CE as each scope may have a different CE value.

 

 

John


Edited by jdupton, 30 July 2016 - 09:34 AM.

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#12 wookie1965

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Posted 30 July 2016 - 10:39 AM

John,

           Thank you for your reply which helps in the most part I.E caution message I will do a 3 star alignment next time. I wrote about this error to give anyone full information, twice now objects I`m looking at are dead centre when starting out but start getting further and further to the right until they are not even in view I wrote about the caution message to see if it was that which is causing this.

 

 

             Paul



#13 jdupton

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Posted 30 July 2016 - 12:10 PM

Paul,

 

   You do not have to do a three star alignment every time. The message concerning NPE is not an error or really (in my opinion) even a caution. It's simply informational in that it lets you know it is reusing data that shouldn't have changed much since the last time you used your telescope. I sort of question why SkyWatcher used the word "Caution" in the message instead of "FYI:" or something less dramatic.

 

   Your second question about decreasing accuracy of GoTos as you move around the sky can be caused by one of two problems (or both).

 

   The first issue is physical polar alignment of the mount. The better polar aligned you are, the better GoTos will be after doing you star alignment. You should be in pretty good shape if you polar align with the polar scope and are very careful with getting Polaris in the correct place on the reticle (after carefully orienting the polar scope).

 

   You can improve on the physical polar alignment of the mount by using the HandBox Polar Alignment assistant. (See section 11.3 of the SynScan Users Manual.) 

 

   The second issue that can affect GoTos is the choice of stars you use during your three star alignment as well as how you center them. There is a rather detailed description of how to best choose alignment stars in the SynScan Users Manual. See section 3.7 of the appropriate manual. When performing the star alignment procedure, be sure to use the "finish centering with the up and right buttons" advice. (See section 3.6). (Below are links to the manuals for both the Version 3 HandBox (older model) and the newer Version 4 HandBox. (Both HandBox version have exactly the same functionality.)

 

Version 4 HandBox

http://ca.skywatcher...01415653194.pdf

 

Version 3 HandBox

http://ca.skywatcher...01415653149.pdf

 

   Section 3.7.3 in particular, gives guidelines on selecting the best possible stars for a three star alignment. You can use any stars visible from your location but following these guidelines will give better pointing accuracy across the sky than just choosing any three random alignment stars.

 

   I realize all this is a lot to remember. You can use the scope without doing any of this and GoTos will be generally OK. If you want the best possible GoTos from the HandBox, try to learn these "Best Practices Rules". After a while they will become second nature to you.

 

   For the ultimate in pointing accuracy, you can consider using EQMOD software. This has the disadvantage of requiring you to take a laptop when observing although it does add the feature (among many advantages) of being able to run a planetarium program to see the sky on the screen and then doing GoTos by pointing and clicking on the map of the sky.

 

 

John


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#14 wookie1965

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Posted 30 July 2016 - 12:56 PM

John,

            Thank you so much for that information a lot to take in, a steep learning curve but hopefully i can not sort it and get a good nights viewing,  I gratefully appreciate you taking the time out to help thank you once again. Could you post a link to the right cable please coming up with vga cable when i type in RS232c in.

 

Paul


Edited by wookie1965, 30 July 2016 - 01:05 PM.


#15 Trenaj

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Posted 01 June 2017 - 09:28 AM

Update to the manual location

http://skywatcher.co...uction-manuals/



#16 StrStrck

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Posted 01 June 2017 - 10:36 AM

John,

           Thank you for your reply which helps in the most part I.E caution message I will do a 3 star alignment next time. I wrote about this error to give anyone full information, twice now objects I`m looking at are dead centre when starting out but start getting further and further to the right until they are not even in view I wrote about the caution message to see if it was that which is causing this.

 

 

             Paul

Check balance, remember to stay East heavy https://www.cloudyni...l-in-the-blank/

I read on a blog somewhere, that after exact (as exact as it goes) positioning of counter weights moving them half an inch in either direction according to which end is pointing East, should suffice. But if you´re spontaniously star hopping (or star shopping as I call it), and crossing the meridian now and then, using the "bean bag trick" described in the above linked thread would be easier.

 

And thanks to above posters for clarifying the NPE warning, that had me puzzled (as well as ignoring) too!



#17 Astrolite

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Posted 19 March 2019 - 06:19 PM

Lots of good info there John, thank you!




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