Date   

Re: New file uploaded to ap-gto

Ray Gralak
 

Hi Cytan,

Just looking at the source code, the ResistSwitch() algorithm looks like simple proportional control with gain =
aggression value. If that's the case, then it is nearly impossible to screw it up. This means that it has to be
downstream of ResistSwitch() which unfortunately, means that the GTOCP4 firmware when absolute encoders are
enabled cannot be ruled out as the culprit.
I doubt that very much.

There are many other ways PHD2 could have a bug, for instance incorrectly calculating the calibration values it is using, incorrectly calculating or rounding up move durations, etc.

-Ray Gralak
Author of APCC (Astro-Physics Command Center): http://www.astro-physics.com/index.htm?products/accessories/software/apcc/apcc
Author of PEMPro V3: https://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver


-----Original Message-----
From: ap-gto@yahoogroups.com [mailto:ap-gto@yahoogroups.com]
Sent: Tuesday, May 7, 2019 5:56 AM
To: ap-gto@yahoogroups.com
Subject: Re: [ap-gto] New file uploaded to ap-gto



HI Ray,
Just looking at the source code, the ResistSwitch() algorithm looks like simple proportional control with gain =
aggression value. If that's the case, then it is nearly impossible to screw it up. This means that it has to be
downstream of ResistSwitch() which unfortunately, means that the GTOCP4 firmware when absolute encoders are
enabled cannot be ruled out as the culprit.

I hope that Andy Glasso who is one of the maintainers of PHD2 is able to shed light on this matter.

cytan

On Tuesday, May 7, 2019, 7:46:57 AM CDT, 'Ray Gralak (Groups)' groups3@gralak.com [ap-gto] <ap-
gto@yahoogroups.com> wrote:




Hi Cytan,

Let's try something that is not way off left field about PHD2: there may be a bug.
I'm pretty sure there are bugs in both MaximDL and PHD2. Almost every non-trivial program has bugs.

But, even if there is a bug and if PHD2 guided better than MaximDL, my point was that I think PHD2 has stepped
away from its roots. The goal of the initial version was to be simple to operate... and the original version was. I think
PHD2 has become more complicated than it needs to be, maybe because it's open source and many of the people
making the changes each had their own ideas on how autoguiding *should* work.

The developers behind MaximDL have been doing this for 25+ years. They have gathered experience using
numerous mount types and operating under a wide range of field conditions. Because the product is commercial
they had resources to buy test equipment like cameras and mounts and hire people to test/develop.

But, as I said previously, I am sure many (most?) are willing to save $500 for software even if it compromises ease
of use and performance.

-Ray Gralak
Author of APCC (Astro-Physics Command Center): http://www.astro-
physics.com/index.htm?products/accessories/software/apcc/apcc
Author of PEMPro V3: https://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver

-----Original Message-----
From: ap-gto@yahoogroups.com [mailto:ap-gto@yahoogroups.com]
Sent: Tuesday, May 7, 2019 4:14 AM
To: 'Ray Gralak (Groups)' groups3@gralak.com [ap-gto]
Subject: Re: [ap-gto] New file uploaded to ap-gto



Let's try something that is not way off left field about PHD2: there may be a bug.

I looked at the source code:

https://github.com/OpenPHDGuiding/phd2/blob/master/guide_algorithm_resistswitch.cpp


The member function that does the dirty work is


double GuideAlgorithmResistSwitch::result(double input)


Unfortunately, I don't see anything obviously wrong with the ResistSwitch algorithm right now. It looks like the
ResistSwitch algorithm just takes the input (which I assume is the error) and multiplies it by the aggression setting
and returns it back to the caller.

cytan


On Monday, May 6, 2019, 10:48:12 PM CDT, 'Ray Gralak (Groups)' groups3@gralak.com [ap-gto] <ap-
gto@yahoogroups.com> wrote:




What's interesting about this discussion is that "PHD" is supposed to be simple to use, but I think the PHD2
developers lost track
of that by adding too many features and knobs.

Now, MaximDL is the easy tool to use. And, apparently MaximDL works better.

-Ray Gralak
Author of APCC (Astro-Physics Command Center): http://www.astro-
physics.com/index.htm?products/accessories/software/apcc/apcc
Author of PEMPro V3: https://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver

-----Original Message-----
From: ap-gto@yahoogroups.com [mailto:ap-gto@yahoogroups.com]
Sent: Monday, May 6, 2019 8:34 PM
To: ap-gto@yahoogroups.com; andy.galasso@gmail.com
Subject: Re: [ap-gto] New file uploaded to ap-gto



Adding Andy Glasso to the thread here. There has got to be a way to set PHD2 to work similarly to your
experience
with MaximDL.

________________________________

From: ap-gto@yahoogroups.com <ap-gto@yahoogroups.com> on behalf of chris1011@aol.com [ap-gto] <ap-
gto@yahoogroups.com>
Sent: Monday, May 6, 2019 7:00 PM
To: ap-gto@yahoogroups.com
Subject: Re: [ap-gto] New file uploaded to ap-gto



Max move doesn't come into play for small corrections on the order of 1 arc sec.


Rolando




-----Original Message-----
From: Bill Long bill@outlook.com [ap-gto] <ap-gto@yahoogroups.com>
To: ap-gto@yahoogroups.com <ap-gto@yahoogroups.com>
Sent: Mon, May 6, 2019 8:41 pm
Subject: Re: [ap-gto] New file uploaded to ap-gto




Hey Roland,

Did you try lowering the MxDEC value in PHD? That will allow you to change the maximum size of a correction,
without changing the aggression. I use 2000 and have used 1500 in the past with good success. The default is
2500
and at 28% aggressiveness as you mentioned, it would only apply up to a 700 move. Maybe put the aggression
back to 100% and set MxDEC to 1500?

________________________________

From: ap-gto@yahoogroups.com <ap-gto@yahoogroups.com> on behalf of chris1011@aol.com [ap-gto] <ap-
gto@yahoogroups.com>
Sent: Monday, May 6, 2019 6:27 PM
To: ap-gto@yahoogroups.com
Subject: Re: [ap-gto] New file uploaded to ap-gto


Hi Cytan,


There is no way that the encoders have anything to do with causing Dec aggressiveness to behave this way.
The
encoders work perfectly with MaximDL at the proper settings of 100% aggressiveness.


And yes, you are getting the same instability as I was getting.



Rolando




-----Original Message-----
From: cytan299@yahoo.com [ap-gto] <ap-gto@yahoogroups.com>
To: ap-gto <ap-gto@yahoogroups.com>
Sent: Mon, May 6, 2019 7:59 pm
Subject: Re: [ap-gto] New file uploaded to ap-gto




Hi Rolando,
I'm still experimenting with my AP1100AE with PHD2 settings and saw this on Saturday night. I'm glad that you
may be seeing what I saw and I can confirm what you saw. Please see:

https://groups.yahoo.com/neo/groups/ap-
gto/files/AP1100AE%20and%20PHD2%20DEC%20settings%20%28weird%20behavior%29/
<https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgroups.yahoo.com%2Fneo%2Fgroups%2F
ap-
gto%2Ffiles%2FAP1100AE%2520and%2520PHD2%2520DEC%2520settings%2520%2528weird%2520behavior%
2529%2F&data=02%7C01%7C%7Cf4ceac89efaf44e58d0d08d6d2901818%7C84df9e7fe9f640afb435aaaaaaaaaaa
a%7C1%7C0%7C636927913648814470&sdata=wxgXrSHNJhXmMmp2cw3E77gpgZE34mu8DF%2BVoqf5%2BH
Y%3D&reserved=0>


When I had DEC aggression set to 100%, the DEC behaviour is clearly very odd. Then I turned it off to see
whether
the seeing was that bad. Clearly not! I then set DEC aggression to 50% and it looked a lot better.

Perhaps its the absolute encoders and PHD2 DEC guiding not playing well together?

cytan










Mach 1 tracking problem

Bruce Donzanti
 

Over the past 2 nights I am getting very bad trailing stars.  I've checked all of the usual possible problems: balance, cables, and PA all seem fine.  Clutches are tight and all connections tight.  I tried two cameras to ensure that was not the problem.  I am out of ideas.  My C11" is on the Mach 1 on a steel pier well above ground and has been working fine.  Stacking will occur but getting elongated stars.  Other suggestions?


Re: How to slew using protocol commands to Park position 3

Roland Christen
 

Hello,

I believe you are slewing from a counterweight up position, perhaps because of some setting you are using for meridian delay. The momentary stop in RA then continue slewing in RA sounds exactly like a safety slew.

When parking at the North celestial Pole you would want to use Hour angle and Dec values rather than Alt-az commands. Things get hairy around the pole when using alt-az commands.

The RA value for Park 3 is exactly the same as the one for Park 2 which points at the eastern horizon and is exactly 6 hours from the meridian hour angle. If you have delayed the meridian by 3 hours west, then both Park 2 and Park 3 will send the RA to a 45 degree position instead of a vertical 90 degree position. So, before parking, set the meridian delay to zero.

Rolando



-----Original Message-----
From: dmitri@... [ap-gto]
To: ap-gto
Sent: Tue, May 7, 2019 9:36 pm
Subject: [ap-gto] How to slew using protocol commands to Park position 3



Hello,

I am controlling AP1100 with absolute encoders from C++ code by sending commands to virtual COM port.
Everything seems to work, but one thing.
I try to park the mount in position 3 (parallel to polar axis, counterweight down).
Issuing commands Sz ..# Sa ..#:MS# with values for Az and Alt that APCC shows in this parked position results in correct DEC --- close to 89:59:... but after the mount goes to correct position, it waits a bit and then starts changing RA so that the final position after has the counterweight at about 45 degrees to vertical.

In all positions fat from polar, slewing using Sz , Sa  or Sd .. Sr seems to work just fine.
What is the trick to parking in position 3?  Is there there some magic sequence of commands to move mount to that postion ?

Thanks,
          Dmitri.



How to slew using protocol commands to Park position 3

Dmitri
 

Hello,


I am controlling AP1100 with absolute encoders from C++ code by sending commands to virtual COM port.

Everything seems to work, but one thing.

I try to park the mount in position 3 (parallel to polar axis, counterweight down).

Issuing commands Sz ..# Sa ..#:MS# with values for Az and Alt that APCC shows in this parked position results in correct DEC --- close to 89:59:... but after the mount goes to correct position, it waits a bit and then starts changing RA so that the final position after has the counterweight at about 45 degrees to vertical.


In all positions fat from polar, slewing using Sz , Sa  or Sd .. Sr seems to work just fine.

What is the trick to parking in position 3?  Is there there some magic sequence of commands to move mount to that postion ?


Thanks,

          Dmitri.


Re: New file uploaded to ap-gto

Michael Fulbright <mike.fulbright@...>
 

That is amazing if they haven't added that it is such an important and trivial thing to implement.

I moved on from Maxim about 5 years ago but when I was using it I had a simple post-image script that ran and implemented dither every N.

It was based on this guide settle script and some code to use the modulus of the sequence index for the last frame to determine if it should dither or not.

http://www.winfij.com/maximdl/guider_settle.html

The dither is done by using the ccd.GuiderMoveStar method to change the desired position (randomly) of the guide star on the guide camera.

Then just wait until the guiding has resumed adequately using whatever criteria you choose to implement.

I haven't used a recent Maxim so I don't know if this will work out of the box but the concept should still hold true.

About the only saving grace I found with Maxim was its extensive scripting abilities as it let you implement needed features.  I've personally found Voyager pretty much superior in every way and it has adequate scripting to handle all night automation which is all I needed.

Michael Fulbright



On 5/7/19 12:04 PM, Rodd Dryfoos rodddryfoos@... [ap-gto] wrote:
 
Chris,

Not strictly true.  I have spoken with George a number of times regarding guiding with Maxim (star fade, calibration failure, etc). A qustion comes to mind regarding dithering.  For CMOS users that take short subs, dithering every sub can add significant time to imaging runs and the collection of less data than calculated (between the dither and the dither delay it could add 30 sec per sub--when the subs are 30 sec long, this reduces the amount of data collected by half).

Any way a "dither every 5 subs" feature can be added to Maxim?
Rodd


Re: New file uploaded to ap-gto

Roland Christen
 


you should probably try using the Lowpass2 filter for DEC corrections,
Good point. We'll give it a try.

Rolando


-----Original Message-----
From: stephenjwinston@... [ap-gto]
To: ap-gto
Sent: Tue, May 7, 2019 11:34 am
Subject: Re: [ap-gto] New file uploaded to ap-gto



Hi Roland,

The default guide algorithms in PHD2 do indeed attempt to correct for hysteresis and keep a history of previous guide corrections and apply that history to the current correction.

Given the Mach-2 with encoders should not be suffering from hysteresis, you should probably try using the Lowpass2 filter for DEC corrections, instead of the standard Resist Switch algorithm.  You can select this on the Algorithms tab of the Brain settings.


"LowPass2 is a very conservative, high-impedance algorithm that may be a good choice for users with good seeing conditions and well-behaved mounts with little or no declination backlash."

It would be interesting to see how Lowpass2 behaves, even with higher aggression settings.

Steve




Re: New file uploaded to ap-gto

Roland Christen
 


>My experience with several different mounts here has been that RA seems to need about 60% 
>aggression and Dec needs to be set at less than 30% in order to produce stable results

Just to re-iterate, I can successfully guide my Mach-1 with RA 70% and DEC 100% aggression, and I think a lot of users are using those default values.
That seems to indicate then that I have some setting incorrect. My next clear night will be Friday, at which point I will do a complete do-over with my version of PHD2.

Rolando


-----Original Message-----
From: stephenjwinston@... [ap-gto]
To: ap-gto
Sent: Tue, May 7, 2019 11:22 am
Subject: Re: [ap-gto] New file uploaded to ap-gto



>My experience with several different mounts here has been that RA seems to need about 60% 
>aggression and Dec needs to be set at less than 30% in order to produce stable results

Just to re-iterate, I can successfully guide my Mach-1 with RA 70% and DEC 100% aggression, and I think a lot of users are using those default values.

>One complication: on my program the wrench tool on the bottom right is greyed out and cannot be 
>accessed no matter what I do

That is for the "advanced camera settings", and appears to only be available for certain camera (e.g. it's also greyed out for my ZWO guide cam).  You can still set general camera settings via the "Brain" settings.


---In ap-gto@..., wrote :


And if there really is an issue in how PHD2 is trying to guide AP mounts, it would be great to figure that out.
We will figure it out. We have had many users over the last few years call George about guiding issues with PHD programs (nobody has ever called him that uses MaximDL).

My experience with several different mounts here has been that RA seems to need about 60% aggression and Dec needs to be set at less than 30% in order to produce stable results. There may be a parameter that I have not set correctly and I will go back over all of them again. It's not a simple thing to find them all since they are somewhat scattered in different places.
One complication: on my program the wrench tool on the bottom right is greyed out and cannot be accessed no matter what I do. I would like to fix that but it's not covered in the instructions anywhere.


-----Original Message-----
From: stephenjwinston@... [ap-gto]

To: ap-gto
Sent: Tue, May 7, 2019 10:08 am
Subject: RE: [ap-gto] New file uploaded to ap-gto




>That's not even close to all that Maxim does

Of course - never meant to imply that that is *all* that Maxim does - it obviously does a lot more - but it doesn't change the fact that you need to spend $500 to get those two features (guiding + dithering) that PHD2 provides for free.

>MaximDL may be the winner there... easier to use out of the box and better results

I've never used Maxim so I can't comment on how easy or not it is to use.  I did have a look through it's set-up tutorial and it appears to provide a similar number of parameters you can configure as PHD2 does, so perhaps a determined user can mess it up as much as they could PHD2 ;).

Anyway - many AP customers (myself included) use PHD2 for guiding, so it's really great to see Roland testing with it.  And if there really is an issue in how PHD2 is trying to guide AP mounts, it would be great to figure that out.


---In ap-gto@..., wrote :

> Well, you do need to spend $499 on Maxim DL Pro to get guiding + dithering, which you get
> for free in PHD2, so there is that...

That's not even close to all that Maxim does. But if we're talking about autoguiding, then the goal of that kind of software is to create the sharpest images possible with our equipment. MaximDL may be the winner there... easier to use out of the box and better results.

However, I am sure some people are willing to compromise image quality for $500.

-Ray Gralak
Author of APCC (Astro-Physics Command Center): http://www.astro-physics.com/index.htm?products/accessories/software/apcc/apcc
Author of PEMPro V3: https://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver


> -----Original Message-----
> From: ap-gto@... [mailto:ap-gto@...]
> Sent: Monday, May 6, 2019 8:56 PM
> To: ap-gto@...
> Subject: RE: [ap-gto] New file uploaded to ap-gto
>
>
>
> Well, you do need to spend $499 on Maxim DL Pro to get guiding + dithering, which you get for free in PHD2, so
> there is that...
>
>
>
>





Re: New file uploaded to ap-gto

Stephen Winston
 

Hi Roland,

The default guide algorithms in PHD2 do indeed attempt to correct for hysteresis and keep a history of previous guide corrections and apply that history to the current correction.

Given the Mach-2 with encoders should not be suffering from hysteresis, you should probably try using the Lowpass2 filter for DEC corrections, instead of the standard Resist Switch algorithm.  You can select this on the Algorithms tab of the Brain settings.


"LowPass2 is a very conservative, high-impedance algorithm that may be a good choice for users with good seeing conditions and well-behaved mounts with little or no declination backlash."

It would be interesting to see how Lowpass2 behaves, even with higher aggression settings.

Steve


Re: New file uploaded to ap-gto

Stephen Winston
 

>My experience with several different mounts here has been that RA seems to need about 60% 
>aggression and Dec needs to be set at less than 30% in order to produce stable results

Just to re-iterate, I can successfully guide my Mach-1 with RA 70% and DEC 100% aggression, and I think a lot of users are using those default values.

>One complication: on my program the wrench tool on the bottom right is greyed out and cannot be 
>accessed no matter what I do

That is for the "advanced camera settings", and appears to only be available for certain camera (e.g. it's also greyed out for my ZWO guide cam).  You can still set general camera settings via the "Brain" settings.


---In ap-gto@..., <chris1011@...> wrote :


And if there really is an issue in how PHD2 is trying to guide AP mounts, it would be great to figure that out.
We will figure it out. We have had many users over the last few years call George about guiding issues with PHD programs (nobody has ever called him that uses MaximDL).

My experience with several different mounts here has been that RA seems to need about 60% aggression and Dec needs to be set at less than 30% in order to produce stable results. There may be a parameter that I have not set correctly and I will go back over all of them again. It's not a simple thing to find them all since they are somewhat scattered in different places.
One complication: on my program the wrench tool on the bottom right is greyed out and cannot be accessed no matter what I do. I would like to fix that but it's not covered in the instructions anywhere.


-----Original Message-----
From: stephenjwinston@... [ap-gto] <ap-gto@...>
To: ap-gto <ap-gto@...>
Sent: Tue, May 7, 2019 10:08 am
Subject: RE: [ap-gto] New file uploaded to ap-gto




>That's not even close to all that Maxim does

Of course - never meant to imply that that is *all* that Maxim does - it obviously does a lot more - but it doesn't change the fact that you need to spend $500 to get those two features (guiding + dithering) that PHD2 provides for free.

>MaximDL may be the winner there... easier to use out of the box and better results

I've never used Maxim so I can't comment on how easy or not it is to use.  I did have a look through it's set-up tutorial and it appears to provide a similar number of parameters you can configure as PHD2 does, so perhaps a determined user can mess it up as much as they could PHD2 ;).

Anyway - many AP customers (myself included) use PHD2 for guiding, so it's really great to see Roland testing with it.  And if there really is an issue in how PHD2 is trying to guide AP mounts, it would be great to figure that out.


---In ap-gto@..., <groups3@...> wrote :

> Well, you do need to spend $499 on Maxim DL Pro to get guiding + dithering, which you get
> for free in PHD2, so there is that...

That's not even close to all that Maxim does. But if we're talking about autoguiding, then the goal of that kind of software is to create the sharpest images possible with our equipment. MaximDL may be the winner there... easier to use out of the box and better results.

However, I am sure some people are willing to compromise image quality for $500.

-Ray Gralak
Author of APCC (Astro-Physics Command Center): http://www.astro-physics.com/index.htm?products/accessories/software/apcc/apcc
Author of PEMPro V3: https://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver


> -----Original Message-----
> From: ap-gto@... [mailto:ap-gto@...]
> Sent: Monday, May 6, 2019 8:56 PM
> To: ap-gto@...
> Subject: RE: [ap-gto] New file uploaded to ap-gto
>
>
>
> Well, you do need to spend $499 on Maxim DL Pro to get guiding + dithering, which you get for free in PHD2, so
> there is that...
>
>
>
>



Re: New file uploaded to ap-gto

Roland Christen
 


Any way a "dither every 5 subs" feature can be added to Maxim?
I'm not Chris, but asking here about changes to MaximDL is not productive. You would need to talk with the guys at Cyanogen (Doug George) who produce the program.

And yes, producing a proper calibration is the only way that the program works, and indeed if you lose the guide star you are out of luck. This is one weakness with MaximDL because it starts hunting and you can end up way far from your desired position after several minutes.

When you dither with our encoder mounts you can set it up so that the guide star comes right back within one or two guide exposures. It only takes a few seconds to be back tracking, so you are not losing 30 seconds of imaging time. The other thing is that for a 30 second exposure you really don't need to guide if your polar alignment is good.

Rolando


-----Original Message-----
From: Rodd Dryfoos rodddryfoos@... [ap-gto]
To: ap-gto
Sent: Tue, May 7, 2019 11:05 am
Subject: Re: [ap-gto] New file uploaded to ap-gto



Chris,

Not strictly true.  I have spoken with George a number of times regarding guiding with Maxim (star fade, calibration failure, etc). A qustion comes to mind regarding dithering.  For CMOS users that take short subs, dithering every sub can add significant time to imaging runs and the collection of less data than calculated (between the dither and the dither delay it could add 30 sec per sub--when the subs are 30 sec long, this reduces the amount of data collected by half).

Any way a "dither every 5 subs" feature can be added to Maxim?
Rodd



Re: New file uploaded to ap-gto

Rodd Dryfoos <rodddryfoos@...>
 

Chris,

Not strictly true.  I have spoken with George a number of times regarding guiding with Maxim (star fade, calibration failure, etc). A qustion comes to mind regarding dithering.  For CMOS users that take short subs, dithering every sub can add significant time to imaging runs and the collection of less data than calculated (between the dither and the dither delay it could add 30 sec per sub--when the subs are 30 sec long, this reduces the amount of data collected by half).

Any way a "dither every 5 subs" feature can be added to Maxim?
Rodd


Re: New file uploaded to ap-gto

Roland Christen
 


And if there really is an issue in how PHD2 is trying to guide AP mounts, it would be great to figure that out.
We will figure it out. We have had many users over the last few years call George about guiding issues with PHD programs (nobody has ever called him that uses MaximDL).

My experience with several different mounts here has been that RA seems to need about 60% aggression and Dec needs to be set at less than 30% in order to produce stable results. There may be a parameter that I have not set correctly and I will go back over all of them again. It's not a simple thing to find them all since they are somewhat scattered in different places.
One complication: on my program the wrench tool on the bottom right is greyed out and cannot be accessed no matter what I do. I would like to fix that but it's not covered in the instructions anywhere.


-----Original Message-----
From: stephenjwinston@... [ap-gto]
To: ap-gto <ap-gto@...>
Sent: Tue, May 7, 2019 10:08 am
Subject: RE: [ap-gto] New file uploaded to ap-gto




>That's not even close to all that Maxim does

Of course - never meant to imply that that is *all* that Maxim does - it obviously does a lot more - but it doesn't change the fact that you need to spend $500 to get those two features (guiding + dithering) that PHD2 provides for free.

>MaximDL may be the winner there... easier to use out of the box and better results

I've never used Maxim so I can't comment on how easy or not it is to use.  I did have a look through it's set-up tutorial and it appears to provide a similar number of parameters you can configure as PHD2 does, so perhaps a determined user can mess it up as much as they could PHD2 ;).

Anyway - many AP customers (myself included) use PHD2 for guiding, so it's really great to see Roland testing with it.  And if there really is an issue in how PHD2 is trying to guide AP mounts, it would be great to figure that out.


---In ap-gto@..., wrote :

> Well, you do need to spend $499 on Maxim DL Pro to get guiding + dithering, which you get
> for free in PHD2, so there is that...

That's not even close to all that Maxim does. But if we're talking about autoguiding, then the goal of that kind of software is to create the sharpest images possible with our equipment. MaximDL may be the winner there... easier to use out of the box and better results.

However, I am sure some people are willing to compromise image quality for $500.

-Ray Gralak
Author of APCC (Astro-Physics Command Center): http://www.astro-physics.com/index.htm?products/accessories/software/apcc/apcc
Author of PEMPro V3: https://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver


> -----Original Message-----
> From: ap-gto@... [mailto:ap-gto@...]
> Sent: Monday, May 6, 2019 8:56 PM
> To: ap-gto@...
> Subject: RE: [ap-gto] New file uploaded to ap-gto
>
>
>
> Well, you do need to spend $499 on Maxim DL Pro to get guiding + dithering, which you get for free in PHD2, so
> there is that...
>
>
>
>



Re: New file uploaded to ap-gto

Roland Christen
 


the GTOCP4 firmware when absolute encoders are enabled cannot be ruled out as the culprit.
I'm afraid that the same instability at 100% aggression occurs when the encoders are turned off. Enabling or disabling encoders changes nothing as far as creating large oscillations at high aggression.

Our encoder algorithm is deadly accurate. We have verified this both in the lab and on the sky. Sending a 1/4 arc sec command to the mount produces exactly 1/4 arc second motion on the axis. Some people don't understand what encoders do, and I get that. However, motion control using encoders is a well understood and mature art that is routinely used in all kinds of machine tool applications. It is not some dark magic thing that has just emerged. The fact that our system works just as predicted with the standard of guiding, MaximDL means that there really isn't anything that the mount is doing. The mount will take an input command and act upon it, it will not move any more or any less than commanded.

Here's the thing, almost all mounts, especially the inexpensive type, will have a dead band around zero on the axis that is not moving, i.e. the Dec axis. This dead band is also known as hysteresis, sticktion, backlash, etc. It means that there is not a 1:1 correlation between an input command and the final axis position. Typically at the zero point, sending a 1 arc sec move command might produce only a 0.1 arc sec axis motion. The next 1 arc sec command might cause a 0.2 arc sec movement, and so on. Eventually if enough commands are sent, the axis will actually move in a 1:1 fashion and will have moved 1 arc sec. Some guide algorithms in the past have tried to compensate for this hysteresis (Losmandy has such an algorithm in their early controllers). The idea is to send a large pulse to "break out" of this dead zone quickly and get the axis moving. This might have worked ok on mounts that had hysteresis, but for a precision encoder mount it causes overshoot and ends with oscillations simply because an encoder mount will move exactly as commanded and not any less. The only way to tame this is to reduce the gain or aggression to a small value.

Roland Christen


-----Original Message-----
From: Cheng-Yang Tan cytan299@... [ap-gto]
To: ap-gto
Sent: Tue, May 7, 2019 7:57 am
Subject: Re: [ap-gto] New file uploaded to ap-gto



HI Ray,
   Just looking at the source code, the ResistSwitch() algorithm looks like simple proportional control with gain = aggression value. If that's the case, then it is nearly impossible to screw it up. This means that it has to be downstream of ResistSwitch() which unfortunately, means that the GTOCP4 firmware when absolute encoders are enabled cannot be ruled out as the culprit.

  I hope that Andy Glasso who is one of the maintainers of PHD2 is able to shed light on this matter.

cytan

On Tuesday, May 7, 2019, 7:46:57 AM CDT, 'Ray Gralak (Groups)' groups3@... [ap-gto] wrote:


 
Hi Cytan,

> Let's try something that is not way off left field about PHD2: there may be a bug.

I'm pretty sure there are bugs in both MaximDL and PHD2. Almost every non-trivial program has bugs.

But, even if there is a bug and if PHD2 guided better than MaximDL, my point was that I think PHD2 has stepped away from its roots. The goal of the initial version was to be simple to operate... and the original version was. I think PHD2 has become more complicated than it needs to be, maybe because it's open source and many of the people making the changes each had their own ideas on how autoguiding *should* work.

The developers behind MaximDL have been doing this for 25+ years. They have gathered experience using numerous mount types and operating under a wide range of field conditions. Because the product is commercial they had resources to buy test equipment like cameras and mounts and hire people to test/develop.

But, as I said previously, I am sure many (most?) are willing to save $500 for software even if it compromises ease of use and performance.

-Ray Gralak
Author of APCC (Astro-Physics Command Center): http://www.astro-physics.com/index.htm?products/accessories/software/apcc/apcc
Author of PEMPro V3: https://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver

> -----Original Message-----
> From: ap-gto@... [mailto:ap-gto@...]
> Sent: Tuesday, May 7, 2019 4:14 AM
> To: 'Ray Gralak (Groups)' groups3@... [ap-gto]
> Subject: Re: [ap-gto] New file uploaded to ap-gto
>
>
>
> Let's try something that is not way off left field about PHD2: there may be a bug.
>
> I looked at the source code:
>
> https://github.com/OpenPHDGuiding/phd2/blob/master/guide_algorithm_resistswitch.cpp
>
>
> The member function that does the dirty work is
>
>
> double GuideAlgorithmResistSwitch::result(double input)
>
>
> Unfortunately, I don't see anything obviously wrong with the ResistSwitch algorithm right now. It looks like the
> ResistSwitch algorithm just takes the input (which I assume is the error) and multiplies it by the aggression setting
> and returns it back to the caller.
>
> cytan
>
>
> On Monday, May 6, 2019, 10:48:12 PM CDT, 'Ray Gralak (Groups)' groups3@... [ap-gto] > gto@...> wrote:
>
>
>
>
> What's interesting about this discussion is that "PHD" is supposed to be simple to use, but I think the PHD2
> developers lost track
> of that by adding too many features and knobs.
>
> Now, MaximDL is the easy tool to use. And, apparently MaximDL works better.
>
> -Ray Gralak
> Author of APCC (Astro-Physics Command Center): http://www.astro-
> physics.com/index.htm?products/accessories/software/apcc/apcc
> Author of PEMPro V3: https://www.ccdware.com
> Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver
>
> > -----Original Message-----
> > From: ap-gto@... [mailto:ap-gto@...]
> > Sent: Monday, May 6, 2019 8:34 PM
> > To: ap-gto@...; andy.galasso@...
> > Subject: Re: [ap-gto] New file uploaded to ap-gto
> >
> >
> >
> > Adding Andy Glasso to the thread here. There has got to be a way to set PHD2 to work similarly to your
> experience
> > with MaximDL.
> >
> > ________________________________
> >
> > From: ap-gto@... on behalf of chris1011@... [ap-gto] > > gto@...>
> > Sent: Monday, May 6, 2019 7:00 PM
> > To: ap-gto@...
> > Subject: Re: [ap-gto] New file uploaded to ap-gto
> >
> >
> >
> > Max move doesn't come into play for small corrections on the order of 1 arc sec.
> >
> >
> > Rolando
> >
> >
> >
> >
> > -----Original Message-----
> > From: Bill Long bill@... [ap-gto]
> > To: ap-gto@...
> > Sent: Mon, May 6, 2019 8:41 pm
> > Subject: Re: [ap-gto] New file uploaded to ap-gto
> >
> >
> >
> >
> > Hey Roland,
> >
> > Did you try lowering the MxDEC value in PHD? That will allow you to change the maximum size of a correction,
> > without changing the aggression. I use 2000 and have used 1500 in the past with good success. The default is
> 2500
> > and at 28% aggressiveness as you mentioned, it would only apply up to a 700 move. Maybe put the aggression
> > back to 100% and set MxDEC to 1500?
> >
> > ________________________________
> >
> > From: ap-gto@... on behalf of chris1011@... [ap-gto] > > gto@...>
> > Sent: Monday, May 6, 2019 6:27 PM
> > To: ap-gto@...
> > Subject: Re: [ap-gto] New file uploaded to ap-gto
> >
> >
> > Hi Cytan,
> >
> >
> > There is no way that the encoders have anything to do with causing Dec aggressiveness to behave this way. The
> > encoders work perfectly with MaximDL at the proper settings of 100% aggressiveness.
> >
> >
> > And yes, you are getting the same instability as I was getting.
> >
> >
> >
> > Rolando
> >
> >
> >
> >
> > -----Original Message-----
> > From: cytan299@... [ap-gto]
> > To: ap-gto > > Sent: Mon, May 6, 2019 7:59 pm
> > Subject: Re: [ap-gto] New file uploaded to ap-gto
> >
> >
> >
> >
> > Hi Rolando,
> > I'm still experimenting with my AP1100AE with PHD2 settings and saw this on Saturday night. I'm glad that you
> > may be seeing what I saw and I can confirm what you saw. Please see:
> >
> > https://groups.yahoo.com/neo/groups/ap-
> > gto/files/AP1100AE%20and%20PHD2%20DEC%20settings%20%28weird%20behavior%29/
> >
> > > ap-
> >
> gto%2Ffiles%2FAP1100AE%2520and%2520PHD2%2520DEC%2520settings%2520%2528weird%2520behavior%
> >
> 2529%2F&data=02%7C01%7C%7Cf4ceac89efaf44e58d0d08d6d2901818%7C84df9e7fe9f640afb435aaaaaaaaaaa
> >
> a%7C1%7C0%7C636927913648814470&sdata=wxgXrSHNJhXmMmp2cw3E77gpgZE34mu8DF%2BVoqf5%2BH
> > Y%3D&reserved=0>
> >
> >
> > When I had DEC aggression set to 100%, the DEC behaviour is clearly very odd. Then I turned it off to see
> whether
> > the seeing was that bad. Clearly not! I then set DEC aggression to 50% and it looked a lot better.
> >
> > Perhaps its the absolute encoders and PHD2 DEC guiding not playing well together?
> >
> > cytan
> >
> >
> >
> >
> >
> >
>
>
>
>




Re: New file uploaded to ap-gto

Stephen Winston
 


>That's not even close to all that Maxim does

Of course - never meant to imply that that is *all* that Maxim does - it obviously does a lot more - but it doesn't change the fact that you need to spend $500 to get those two features (guiding + dithering) that PHD2 provides for free.

>MaximDL may be the winner there... easier to use out of the box and better results

I've never used Maxim so I can't comment on how easy or not it is to use.  I did have a look through it's set-up tutorial and it appears to provide a similar number of parameters you can configure as PHD2 does, so perhaps a determined user can mess it up as much as they could PHD2 ;).

Anyway - many AP customers (myself included) use PHD2 for guiding, so it's really great to see Roland testing with it.  And if there really is an issue in how PHD2 is trying to guide AP mounts, it would be great to figure that out.


---In ap-gto@..., <groups3@...> wrote :

> Well, you do need to spend $499 on Maxim DL Pro to get guiding + dithering, which you get
> for free in PHD2, so there is that...

That's not even close to all that Maxim does. But if we're talking about autoguiding, then the goal of that kind of software is to create the sharpest images possible with our equipment. MaximDL may be the winner there... easier to use out of the box and better results.

However, I am sure some people are willing to compromise image quality for $500.

-Ray Gralak
Author of APCC (Astro-Physics Command Center): http://www.astro-physics.com/index.htm?products/accessories/software/apcc/apcc
Author of PEMPro V3: https://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver


> -----Original Message-----
> From: ap-gto@... [mailto:ap-gto@...]
> Sent: Monday, May 6, 2019 8:56 PM
> To: ap-gto@...
> Subject: RE: [ap-gto] New file uploaded to ap-gto
>
>
>
> Well, you do need to spend $499 on Maxim DL Pro to get guiding + dithering, which you get for free in PHD2, so
> there is that...
>
>
>
>


Re: New file uploaded to ap-gto

Stephen Winston
 

Just to go back to Roland's original post on this:

"Turning on the guiding produced huge oscillations in both RA and Dec that could only be tamed by setting the aggressiveness to a very low value"

So this is not a DEC (or ResistSwitch) specific issue as, unless Roland changed it, RA doesn't use ResistSwitch.

I don;t think we can make progress on this until we see the logs showing which guide pulses were actually issued by PHD2 and Maxim, and can compare what's different.


---In ap-gto@..., <bryancashion@...> wrote :

This is what the PHD2 documentation says about ResistSwitch.  Note the sentence discussing mounts with low B/L, i.e. an A-P with AE.

Bryan

The ResistSwitch algorithm behaves much as its name implies.  Like the hysteresis algorithms, it also maintains a history of past guide corrections, and any change of direction must be "compelling" in order to issue a reversing guide command.  This is appropriate for declination guiding, where reversals in direction are both suspect and likely to trigger backlash in the gears.  For that reason, ResistSwitch is the default algorithm for declination but not for right ascension, where valid direction reversals are expected.  Starting with Release 2.4.1, two additional parameters are available for fine-tuning the ResistSwitch algorithm.  The first is "aggression", a percentage amount that controls how much of the computed guide correction will be issued.  Reducing this parameter can help to avoid over-shooting with mounts that have little or no backlash. The second parameter is a checkbox labeled "Fast switch for large deflections."  If this is checked, PHD2 will react immediately to a large change of direction rather than waiting for three consecutive deflections in the new direction, which is the normal behavior.  This can help to more quickly recover from large excursions in Dec, perhaps caused by wind, cable snags, or other mechanical shifts  The definition of a "large deflection" is 3x the minimum-move value.  So if PHD2 is over-reacting to direction changes, you can tune the behavior with the min-move parameter or disable the "fast switch" option altogether.  It is worth remembering that "less is usually better" when it comes to Dec guiding, so don't try to over-tune these parameters.





Re: New file uploaded to ap-gto

Worsel
 

This is what the PHD2 documentation says about ResistSwitch.  Note the sentence discussing mounts with low B/L, i.e. an A-P with AE.

Bryan

The ResistSwitch algorithm behaves much as its name implies.  Like the hysteresis algorithms, it also maintains a history of past guide corrections, and any change of direction must be "compelling" in order to issue a reversing guide command.  This is appropriate for declination guiding, where reversals in direction are both suspect and likely to trigger backlash in the gears.  For that reason, ResistSwitch is the default algorithm for declination but not for right ascension, where valid direction reversals are expected.  Starting with Release 2.4.1, two additional parameters are available for fine-tuning the ResistSwitch algorithm.  The first is "aggression", a percentage amount that controls how much of the computed guide correction will be issued.  Reducing this parameter can help to avoid over-shooting with mounts that have little or no backlash. The second parameter is a checkbox labeled "Fast switch for large deflections."  If this is checked, PHD2 will react immediately to a large change of direction rather than waiting for three consecutive deflections in the new direction, which is the normal behavior.  This can help to more quickly recover from large excursions in Dec, perhaps caused by wind, cable snags, or other mechanical shifts  The definition of a "large deflection" is 3x the minimum-move value.  So if PHD2 is over-reacting to direction changes, you can tune the behavior with the min-move parameter or disable the "fast switch" option altogether.  It is worth remembering that "less is usually better" when it comes to Dec guiding, so don't try to over-tune these parameters.





Re: New file uploaded to ap-gto

Cheng-Yang Tan
 

HI Ray,
   Just looking at the source code, the ResistSwitch() algorithm looks like simple proportional control with gain = aggression value. If that's the case, then it is nearly impossible to screw it up. This means that it has to be downstream of ResistSwitch() which unfortunately, means that the GTOCP4 firmware when absolute encoders are enabled cannot be ruled out as the culprit.

  I hope that Andy Glasso who is one of the maintainers of PHD2 is able to shed light on this matter.

cytan

On Tuesday, May 7, 2019, 7:46:57 AM CDT, 'Ray Gralak (Groups)' groups3@... [ap-gto] wrote:


 

Hi Cytan,

> Let's try something that is not way off left field about PHD2: there may be a bug.

I'm pretty sure there are bugs in both MaximDL and PHD2. Almost every non-trivial program has bugs.

But, even if there is a bug and if PHD2 guided better than MaximDL, my point was that I think PHD2 has stepped away from its roots. The goal of the initial version was to be simple to operate... and the original version was. I think PHD2 has become more complicated than it needs to be, maybe because it's open source and many of the people making the changes each had their own ideas on how autoguiding *should* work.

The developers behind MaximDL have been doing this for 25+ years. They have gathered experience using numerous mount types and operating under a wide range of field conditions. Because the product is commercial they had resources to buy test equipment like cameras and mounts and hire people to test/develop.

But, as I said previously, I am sure many (most?) are willing to save $500 for software even if it compromises ease of use and performance.

-Ray Gralak
Author of APCC (Astro-Physics Command Center): http://www.astro-physics.com/index.htm?products/accessories/software/apcc/apcc
Author of PEMPro V3: https://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver

> -----Original Message-----
> From: ap-gto@... [mailto:ap-gto@...]
> Sent: Tuesday, May 7, 2019 4:14 AM
> To: 'Ray Gralak (Groups)' groups3@... [ap-gto]
> Subject: Re: [ap-gto] New file uploaded to ap-gto
>
>
>
> Let's try something that is not way off left field about PHD2: there may be a bug.
>
> I looked at the source code:
>
> https://github.com/OpenPHDGuiding/phd2/blob/master/guide_algorithm_resistswitch.cpp
>
>
> The member function that does the dirty work is
>
>
> double GuideAlgorithmResistSwitch::result(double input)
>
>
> Unfortunately, I don't see anything obviously wrong with the ResistSwitch algorithm right now. It looks like the
> ResistSwitch algorithm just takes the input (which I assume is the error) and multiplies it by the aggression setting
> and returns it back to the caller.
>
> cytan
>
>
> On Monday, May 6, 2019, 10:48:12 PM CDT, 'Ray Gralak (Groups)' groups3@... [ap-gto] > gto@...> wrote:
>
>
>
>
> What's interesting about this discussion is that "PHD" is supposed to be simple to use, but I think the PHD2
> developers lost track
> of that by adding too many features and knobs.
>
> Now, MaximDL is the easy tool to use. And, apparently MaximDL works better.
>
> -Ray Gralak
> Author of APCC (Astro-Physics Command Center): http://www.astro-
> physics.com/index.htm?products/accessories/software/apcc/apcc
> Author of PEMPro V3: https://www.ccdware.com
> Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver
>
> > -----Original Message-----
> > From: ap-gto@... [mailto:ap-gto@...]
> > Sent: Monday, May 6, 2019 8:34 PM
> > To: ap-gto@...; andy.galasso@...
> > Subject: Re: [ap-gto] New file uploaded to ap-gto
> >
> >
> >
> > Adding Andy Glasso to the thread here. There has got to be a way to set PHD2 to work similarly to your
> experience
> > with MaximDL.
> >
> > ________________________________
> >
> > From: ap-gto@... on behalf of chris1011@... [ap-gto] > > gto@...>
> > Sent: Monday, May 6, 2019 7:00 PM
> > To: ap-gto@...
> > Subject: Re: [ap-gto] New file uploaded to ap-gto
> >
> >
> >
> > Max move doesn't come into play for small corrections on the order of 1 arc sec.
> >
> >
> > Rolando
> >
> >
> >
> >
> > -----Original Message-----
> > From: Bill Long bill@... [ap-gto]
> > To: ap-gto@... > > Sent: Mon, May 6, 2019 8:41 pm
> > Subject: Re: [ap-gto] New file uploaded to ap-gto
> >
> >
> >
> >
> > Hey Roland,
> >
> > Did you try lowering the MxDEC value in PHD? That will allow you to change the maximum size of a correction,
> > without changing the aggression. I use 2000 and have used 1500 in the past with good success. The default is
> 2500
> > and at 28% aggressiveness as you mentioned, it would only apply up to a 700 move. Maybe put the aggression
> > back to 100% and set MxDEC to 1500?
> >
> > ________________________________
> >
> > From: ap-gto@... on behalf of chris1011@... [ap-gto] > > gto@...>
> > Sent: Monday, May 6, 2019 6:27 PM
> > To: ap-gto@...
> > Subject: Re: [ap-gto] New file uploaded to ap-gto
> >
> >
> > Hi Cytan,
> >
> >
> > There is no way that the encoders have anything to do with causing Dec aggressiveness to behave this way. The
> > encoders work perfectly with MaximDL at the proper settings of 100% aggressiveness.
> >
> >
> > And yes, you are getting the same instability as I was getting.
> >
> >
> >
> > Rolando
> >
> >
> >
> >
> > -----Original Message-----
> > From: cytan299@... [ap-gto]
> > To: ap-gto
> > Sent: Mon, May 6, 2019 7:59 pm
> > Subject: Re: [ap-gto] New file uploaded to ap-gto
> >
> >
> >
> >
> > Hi Rolando,
> > I'm still experimenting with my AP1100AE with PHD2 settings and saw this on Saturday night. I'm glad that you
> > may be seeing what I saw and I can confirm what you saw. Please see:
> >
> > https://groups.yahoo.com/neo/groups/ap-
> > gto/files/AP1100AE%20and%20PHD2%20DEC%20settings%20%28weird%20behavior%29/
> >
> > > ap-
> >
> gto%2Ffiles%2FAP1100AE%2520and%2520PHD2%2520DEC%2520settings%2520%2528weird%2520behavior%
> >
> 2529%2F&data=02%7C01%7C%7Cf4ceac89efaf44e58d0d08d6d2901818%7C84df9e7fe9f640afb435aaaaaaaaaaa
> >
> a%7C1%7C0%7C636927913648814470&sdata=wxgXrSHNJhXmMmp2cw3E77gpgZE34mu8DF%2BVoqf5%2BH
> > Y%3D&reserved=0>
> >
> >
> > When I had DEC aggression set to 100%, the DEC behaviour is clearly very odd. Then I turned it off to see
> whether
> > the seeing was that bad. Clearly not! I then set DEC aggression to 50% and it looked a lot better.
> >
> > Perhaps its the absolute encoders and PHD2 DEC guiding not playing well together?
> >
> > cytan
> >
> >
> >
> >
> >
> >
>
>
>
>


Re: New file uploaded to ap-gto

Ray Gralak
 

Hi Cytan,

Let's try something that is not way off left field about PHD2: there may be a bug.
I'm pretty sure there are bugs in both MaximDL and PHD2. Almost every non-trivial program has bugs.

But, even if there is a bug and if PHD2 guided better than MaximDL, my point was that I think PHD2 has stepped away from its roots. The goal of the initial version was to be simple to operate... and the original version was. I think PHD2 has become more complicated than it needs to be, maybe because it's open source and many of the people making the changes each had their own ideas on how autoguiding *should* work.

The developers behind MaximDL have been doing this for 25+ years. They have gathered experience using numerous mount types and operating under a wide range of field conditions. Because the product is commercial they had resources to buy test equipment like cameras and mounts and hire people to test/develop.

But, as I said previously, I am sure many (most?) are willing to save $500 for software even if it compromises ease of use and performance.

-Ray Gralak
Author of APCC (Astro-Physics Command Center): http://www.astro-physics.com/index.htm?products/accessories/software/apcc/apcc
Author of PEMPro V3: https://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver


-----Original Message-----
From: ap-gto@yahoogroups.com [mailto:ap-gto@yahoogroups.com]
Sent: Tuesday, May 7, 2019 4:14 AM
To: 'Ray Gralak (Groups)' groups3@gralak.com [ap-gto]
Subject: Re: [ap-gto] New file uploaded to ap-gto



Let's try something that is not way off left field about PHD2: there may be a bug.

I looked at the source code:

https://github.com/OpenPHDGuiding/phd2/blob/master/guide_algorithm_resistswitch.cpp


The member function that does the dirty work is


double GuideAlgorithmResistSwitch::result(double input)


Unfortunately, I don't see anything obviously wrong with the ResistSwitch algorithm right now. It looks like the
ResistSwitch algorithm just takes the input (which I assume is the error) and multiplies it by the aggression setting
and returns it back to the caller.

cytan


On Monday, May 6, 2019, 10:48:12 PM CDT, 'Ray Gralak (Groups)' groups3@gralak.com [ap-gto] <ap-
gto@yahoogroups.com> wrote:




What's interesting about this discussion is that "PHD" is supposed to be simple to use, but I think the PHD2
developers lost track
of that by adding too many features and knobs.

Now, MaximDL is the easy tool to use. And, apparently MaximDL works better.

-Ray Gralak
Author of APCC (Astro-Physics Command Center): http://www.astro-
physics.com/index.htm?products/accessories/software/apcc/apcc
Author of PEMPro V3: https://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver

-----Original Message-----
From: ap-gto@yahoogroups.com [mailto:ap-gto@yahoogroups.com]
Sent: Monday, May 6, 2019 8:34 PM
To: ap-gto@yahoogroups.com; andy.galasso@gmail.com
Subject: Re: [ap-gto] New file uploaded to ap-gto



Adding Andy Glasso to the thread here. There has got to be a way to set PHD2 to work similarly to your
experience
with MaximDL.

________________________________

From: ap-gto@yahoogroups.com <ap-gto@yahoogroups.com> on behalf of chris1011@aol.com [ap-gto] <ap-
gto@yahoogroups.com>
Sent: Monday, May 6, 2019 7:00 PM
To: ap-gto@yahoogroups.com
Subject: Re: [ap-gto] New file uploaded to ap-gto



Max move doesn't come into play for small corrections on the order of 1 arc sec.


Rolando




-----Original Message-----
From: Bill Long bill@outlook.com [ap-gto] <ap-gto@yahoogroups.com>
To: ap-gto@yahoogroups.com <ap-gto@yahoogroups.com>
Sent: Mon, May 6, 2019 8:41 pm
Subject: Re: [ap-gto] New file uploaded to ap-gto




Hey Roland,

Did you try lowering the MxDEC value in PHD? That will allow you to change the maximum size of a correction,
without changing the aggression. I use 2000 and have used 1500 in the past with good success. The default is
2500
and at 28% aggressiveness as you mentioned, it would only apply up to a 700 move. Maybe put the aggression
back to 100% and set MxDEC to 1500?

________________________________

From: ap-gto@yahoogroups.com <ap-gto@yahoogroups.com> on behalf of chris1011@aol.com [ap-gto] <ap-
gto@yahoogroups.com>
Sent: Monday, May 6, 2019 6:27 PM
To: ap-gto@yahoogroups.com
Subject: Re: [ap-gto] New file uploaded to ap-gto


Hi Cytan,


There is no way that the encoders have anything to do with causing Dec aggressiveness to behave this way. The
encoders work perfectly with MaximDL at the proper settings of 100% aggressiveness.


And yes, you are getting the same instability as I was getting.



Rolando




-----Original Message-----
From: cytan299@yahoo.com [ap-gto] <ap-gto@yahoogroups.com>
To: ap-gto <ap-gto@yahoogroups.com>
Sent: Mon, May 6, 2019 7:59 pm
Subject: Re: [ap-gto] New file uploaded to ap-gto




Hi Rolando,
I'm still experimenting with my AP1100AE with PHD2 settings and saw this on Saturday night. I'm glad that you
may be seeing what I saw and I can confirm what you saw. Please see:

https://groups.yahoo.com/neo/groups/ap-
gto/files/AP1100AE%20and%20PHD2%20DEC%20settings%20%28weird%20behavior%29/
<https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgroups.yahoo.com%2Fneo%2Fgroups%2F
ap-
gto%2Ffiles%2FAP1100AE%2520and%2520PHD2%2520DEC%2520settings%2520%2528weird%2520behavior%
2529%2F&data=02%7C01%7C%7Cf4ceac89efaf44e58d0d08d6d2901818%7C84df9e7fe9f640afb435aaaaaaaaaaa
a%7C1%7C0%7C636927913648814470&sdata=wxgXrSHNJhXmMmp2cw3E77gpgZE34mu8DF%2BVoqf5%2BH
Y%3D&reserved=0>


When I had DEC aggression set to 100%, the DEC behaviour is clearly very odd. Then I turned it off to see
whether
the seeing was that bad. Clearly not! I then set DEC aggression to 50% and it looked a lot better.

Perhaps its the absolute encoders and PHD2 DEC guiding not playing well together?

cytan








Re: New file uploaded to ap-gto

Cheng-Yang Tan
 

Let's try something that is not way off left field about PHD2: there may be a bug.

I looked at the source code:


The member function that does the dirty work is 

double GuideAlgorithmResistSwitch::result(double input)

Unfortunately, I don't see anything obviously wrong with the ResistSwitch algorithm right now. It looks like the ResistSwitch algorithm just takes the input (which I assume is the error) and multiplies it by the aggression setting and returns it back to the caller.

cytan


On Monday, May 6, 2019, 10:48:12 PM CDT, 'Ray Gralak (Groups)' groups3@... [ap-gto] wrote:


 

What's interesting about this discussion is that "PHD" is supposed to be simple to use, but I think the PHD2 developers lost track
of that by adding too many features and knobs.

Now, MaximDL is the easy tool to use. And, apparently MaximDL works better.

-Ray Gralak
Author of APCC (Astro-Physics Command Center): http://www.astro-physics.com/index.htm?products/accessories/software/apcc/apcc
Author of PEMPro V3: https://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver

> -----Original Message-----
> From: ap-gto@... [mailto:ap-gto@...]
> Sent: Monday, May 6, 2019 8:34 PM
> To: ap-gto@...; andy.galasso@...
> Subject: Re: [ap-gto] New file uploaded to ap-gto
>
>
>
> Adding Andy Glasso to the thread here. There has got to be a way to set PHD2 to work similarly to your experience
> with MaximDL.
>
> ________________________________
>
> From: ap-gto@... <ap-gto@...> on behalf of chris1011@... [ap-gto] > gto@...>
> Sent: Monday, May 6, 2019 7:00 PM
> To: ap-gto@...
> Subject: Re: [ap-gto] New file uploaded to ap-gto
>
>
>
> Max move doesn't come into play for small corrections on the order of 1 arc sec.
>
>
> Rolando
>
>
>
>
> -----Original Message-----
> From: Bill Long bill@... [ap-gto]
> To: ap-gto@...
> Sent: Mon, May 6, 2019 8:41 pm
> Subject: Re: [ap-gto] New file uploaded to ap-gto
>
>
>
>
> Hey Roland,
>
> Did you try lowering the MxDEC value in PHD? That will allow you to change the maximum size of a correction,
> without changing the aggression. I use 2000 and have used 1500 in the past with good success. The default is 2500
> and at 28% aggressiveness as you mentioned, it would only apply up to a 700 move. Maybe put the aggression
> back to 100% and set MxDEC to 1500?
>
> ________________________________
>
> From: ap-gto@... on behalf of chris1011@... [ap-gto] > gto@...>
> Sent: Monday, May 6, 2019 6:27 PM
> To: ap-gto@...
> Subject: Re: [ap-gto] New file uploaded to ap-gto
>
>
> Hi Cytan,
>
>
> There is no way that the encoders have anything to do with causing Dec aggressiveness to behave this way. The
> encoders work perfectly with MaximDL at the proper settings of 100% aggressiveness.
>
>
> And yes, you are getting the same instability as I was getting.
>
>
>
> Rolando
>
>
>
>
> -----Original Message-----
> From: cytan299@... [ap-gto]
> To: ap-gto
> Sent: Mon, May 6, 2019 7:59 pm
> Subject: Re: [ap-gto] New file uploaded to ap-gto
>
>
>
>
> Hi Rolando,
> I'm still experimenting with my AP1100AE with PHD2 settings and saw this on Saturday night. I'm glad that you
> may be seeing what I saw and I can confirm what you saw. Please see:
>
> https://groups.yahoo.com/neo/groups/ap-
> gto/files/AP1100AE%20and%20PHD2%20DEC%20settings%20%28weird%20behavior%29/
> > ap-
> gto%2Ffiles%2FAP1100AE%2520and%2520PHD2%2520DEC%2520settings%2520%2528weird%2520behavior%
> 2529%2F&data=02%7C01%7C%7Cf4ceac89efaf44e58d0d08d6d2901818%7C84df9e7fe9f640afb435aaaaaaaaaaa
> a%7C1%7C0%7C636927913648814470&sdata=wxgXrSHNJhXmMmp2cw3E77gpgZE34mu8DF%2BVoqf5%2BH
> Y%3D&reserved=0>
>
>
> When I had DEC aggression set to 100%, the DEC behaviour is clearly very odd. Then I turned it off to see whether
> the seeing was that bad. Clearly not! I then set DEC aggression to 50% and it looked a lot better.
>
> Perhaps its the absolute encoders and PHD2 DEC guiding not playing well together?
>
> cytan
>
>
>
>
>
>


Re: Dome Offset setting - 1100gto

carlos49gib@...
 

Thanks guys, Howard I have a diagram of the dome, pier etc and I believe it will be better if I could send you by email this diagram given that I am missing a measurement that I do not see on the Dimension calculator, if you do not mind can I send it via email to you.

Kind Regards

Carlos

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