I have been facing some strange guiding issues since some months and deferred posting here until I could do some experiments and narrow it down somewhat.

The issue happens only during guiding (not tracking) and it is this - A sharp spike in RA guiding graph of +/- 5-10 arcsec occurs periodic with the worm. Upon close observation, the symptom looks like tracking got turned off for a fraction of second and the guider brings the star back.

Here is what I know:

It only happens in RA. Does not matter if PEC on or off.
It only happens when guiding (I have tried Maxim, PHD) using ASCOM and not when using ST4.
It starts happening randomly and stops randomly for certain number of worm periods.
It seems to occur more frequently if I have Sky6 connected to the mount while autoguiding.
Crucially, if I turn on "Sync Pulse-guide" from the Driver, and disconnect TheSky6 from the mount, then it does not happen. If I don't turn on sync pulseguide (driver default) and disconnect TheSky6, the issues happens but less frequently.

Without change to my hardware/software (other than AP drivers), this issue never occurred until perhaps after I updated to the driver a couple of releases ago (I am not sure which one).

So, I have ruled out mount mechanics, OTA mechanics (flexure), PEC, guider settings/calibration, hot pixels. Given the issue sensitivity to "sync pulseguide", I believe the issue is something to do with traffic/collision on the serial port to the mount and driver communication. I have not changed anything in TheSky6 or other applications.

I tested the serial adapter/connectivity using Keyspan utility and and see no issues there.
Has anyone experienced this? Any clues to what could be going on?
I wanted to try reverting back to an old AP V2 driver; is there a link for that? I am afraid the "Sync Pulseguide" may not be optimal for low latency corrections to the mount.

Equipment: AP1200 GTO, C11 EdgeHD @f/10, Atik 314L+ imager and DSI I pro mono guider.

Thanks
Parijat

I think you may be chasing a red herring. All that the "Synchronous PulseGuide calls" option does is prevent
simultaneous RA and Dec pulseguide events. It does this by waiting until each pulseguide command is complete before
returning control back to the client application. It does not change the duration of the PulseGuide commands sent.

That said, there is no reason to have this option set because the mount and the driver fully support simultaneous RA and
Dec PulseGuide commands. Also, it is more efficient to allow asynchronous RA and Dec PulseGuide commands.

If you still see the problem then note the time at which one event happens and send that and the ASCOM driver log file
to Howard or to me for analysis. It is EXTREMELY important to include the time (within a minute) so we can be sure to
look at the right place in the log file.

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: http://www.gralak.com/apdriver
Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

Hi Ray,
Thanks for your response. I will get the log files when the weather clears up.
One question - could high traffic due to async commands and other activity on the Serial link cause command corruption or something to trigger trackinf off command for short times?
Have you ever seen this symptom at all?

Parijat

Hi Parijat,

One question - could high traffic due to async commands and other activity on the Serial link cause command
corruption or something to trigger trackinf off command for short times?

No, but that's not saying that your serial connection couldn't be flakey, thus causing an error occasionally.

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: http://www.gralak.com/apdriver
Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@... [mailto:ap-gto@...] On Behalf Of photonphisher
Sent: Friday, April 13, 2012 2:14 PM
To: ap-gto@...
Subject: [ap-gto] Re: Need help with issue in RA guiding and Synchronous Pulseguide



Hi Ray,
Thanks for your response. I will get the log files when the weather clears up.
One question - could high traffic due to async commands and other activity on the Serial link cause command
corruption or something to trigger trackinf off command for short times?
Have you ever seen this symptom at all?

Parijat

--- In ap-gto@... <mailto:ap-gto%40yahoogroups.com> , "Ray Gralak" <groups1@...> wrote:

I think you may be chasing a red herring. All that the "Synchronous PulseGuide calls" option does is prevent
simultaneous RA and Dec pulseguide events. It does this by waiting until each pulseguide command is complete

before

returning control back to the client application. It does not change the duration of the PulseGuide commands sent.

That said, there is no reason to have this option set because the mount and the driver fully support simultaneous

RA and

Dec PulseGuide commands. Also, it is more efficient to allow asynchronous RA and Dec PulseGuide commands.

If you still see the problem then note the time at which one event happens and send that and the ASCOM driver

log file

to Howard or to me for analysis. It is EXTREMELY important to include the time (within a minute) so we can be

sure to

look at the right place in the log file.

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: http://www.gralak.com/apdriver
Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@... <mailto:ap-gto%40yahoogroups.com> [mailto:ap-gto@...

<mailto:ap-gto%40yahoogroups.com> ] On Behalf Of photonphisher

Sent: Friday, April 13, 2012 9:58 AM
To: ap-gto@... <mailto:ap-gto%40yahoogroups.com>
Subject: [ap-gto] Need help with issue in RA guiding and Synchronous Pulseguide



I have been facing some strange guiding issues since some months and deferred posting here until I could do

some

experiments and narrow it down somewhat.

The issue happens only during guiding (not tracking) and it is this - A sharp spike in RA guiding graph of +/- 5-

10

arcsec occurs periodic with the worm. Upon close observation, the symptom looks like tracking got turned off

for a

fraction of second and the guider brings the star back.

Here is what I know:

It only happens in RA. Does not matter if PEC on or off.
It only happens when guiding (I have tried Maxim, PHD) using ASCOM and not when using ST4.
It starts happening randomly and stops randomly for certain number of worm periods.
It seems to occur more frequently if I have Sky6 connected to the mount while autoguiding.
Crucially, if I turn on "Sync Pulse-guide" from the Driver, and disconnect TheSky6 from the mount, then it does

not

happen. If I don't turn on sync pulseguide (driver default) and disconnect TheSky6, the issues happens but less
frequently.

Without change to my hardware/software (other than AP drivers), this issue never occurred until perhaps after I
updated to the driver a couple of releases ago (I am not sure which one).

So, I have ruled out mount mechanics, OTA mechanics (flexure), PEC, guider settings/calibration, hot pixels.

Given

the issue sensitivity to "sync pulseguide", I believe the issue is something to do with traffic/collision on the

serial port

to the mount and driver communication. I have not changed anything in TheSky6 or other applications.

I tested the serial adapter/connectivity using Keyspan utility and and see no issues there.
Has anyone experienced this? Any clues to what could be going on?
I wanted to try reverting back to an old AP V2 driver; is there a link for that? I am afraid the "Sync Pulseguide"

may

not be optimal for low latency corrections to the mount.

Equipment: AP1200 GTO, C11 EdgeHD @f/10, Atik 314L+ imager and DSI I pro mono guider.

Thanks
Parijat

Ray,

The sync pulse-guide connection was indeed a red herring.
I swapped the keyspan serial adapter with another one, remapped the COM ports and in the last two long imaging sessions, I could not reproduce the issue.

It is nice to have a solid mount which can be ruled out of the equation making the debug space much smaller. I am using this serial adapter on a less traffic link - robofocus.
So far no issues.

Parijat

Hi Ray, Howard,

The RA spike issue has come back again.

I have posted the ASCOM driver log here. The exact minute of time that it happened was 20:33 and 20:36.

http://tinyurl.com/78wpc42

Here is a snapshot of the guider log. The spike happens only in RA during guiding.

http://groups.yahoo.com/group/ap-gto/photos/album/104285095/pic/608492353/view

I have no idea what is going on.

Thanks for your help

Parijat

Here is the fixed link to the ASCOM log file:
http://tech.groups.yahoo.com/group/ap-gto/files/photonphisher/

Parijat

Hi Parijat,

I looked at your log file and I do not see anywhere that the mount was stopping. However, I do see a *big* move sent
from the autoguider program (410 mSecs). Have you checked for a loose spur gear in the motor box?

BIG move here (410 msecs West move)
019233 2012-04-22 20:32:58.609: ASCOM: Info : PulseGuide(3, 410)

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: http://www.gralak.com/apdriver
Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

Hi Ray,
Since I was auto-guiding, the star was brought back after the fast initial movement. So this 410ms is probably that.
Last time I checked the spur gear, it was tight but will check again.
The weird thing is that this issue occurs randomly (e.g. sometimes occurs every period, other times does not occur for 4hrs) and more when TheSky6 is connected.
I would imagine with gear looseness, it would be less random.

Can you tell me what ASCOM command is to stop tracking for the GTOCP3? I was thinking of trying to located that in the serial I/O stream of the Keyspan utility.

Parijat

Hi Parijat,

Since I was auto-guiding, the star was brought back after the fast initial movement. So this 410ms is probably
that.

Actually there were several big moves (all West) in a row. If tracking were stopped the change in RA coordinates would
not match up to the durations of the PulseGuide commands (but they do match up). Is it possible there was a guide star
fade and the autoguider program was mistaking a hot pixel for a star?

Can you tell me what ASCOM command is to stop tracking for the GTOCP3? I was thinking of trying to located
that in the serial I/O stream of the Keyspan utility.

You would see this command ":RT9#", without the double quotes.

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: http://www.gralak.com/apdriver
Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@... [mailto:ap-gto@...] On Behalf Of photonphisher
Sent: Tuesday, April 24, 2012 5:24 AM
To: ap-gto@...
Subject: [ap-gto] Re: Need help with issue in RA guiding and Synchronous Pulseguide



Hi Ray,
Since I was auto-guiding, the star was brought back after the fast initial movement. So this 410ms is probably
that.
Last time I checked the spur gear, it was tight but will check again.
The weird thing is that this issue occurs randomly (e.g. sometimes occurs every period, other times does not
occur for 4hrs) and more when TheSky6 is connected.
I would imagine with gear looseness, it would be less random.

Can you tell me what ASCOM command is to stop tracking for the GTOCP3? I was thinking of trying to located
that in the serial I/O stream of the Keyspan utility.

Parijat

--- In ap-gto@... <mailto:ap-gto%40yahoogroups.com> , "Ray Gralak" <groups1@...> wrote:

Hi Parijat,

I looked at your log file and I do not see anywhere that the mount was stopping. However, I do see a *big* move

sent

from the autoguider program (410 mSecs). Have you checked for a loose spur gear in the motor box?

BIG move here (410 msecs West move)
019233 2012-04-22 20:32:58.609: ASCOM: Info : PulseGuide(3, 410)

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: http://www.gralak.com/apdriver
Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@... <mailto:ap-gto%40yahoogroups.com> [mailto:ap-gto@...

<mailto:ap-gto%40yahoogroups.com> ] On Behalf Of photonphisher

Sent: Monday, April 23, 2012 7:01 PM
To: ap-gto@... <mailto:ap-gto%40yahoogroups.com>
Subject: [ap-gto] Re: Need help with issue in RA guiding and Synchronous Pulseguide



Here is the fixed link to the ASCOM log file:
http://tech.groups.yahoo.com/group/ap-gto/files/photonphisher/

Parijat

--- In ap-gto@... <mailto:ap-gto%40yahoogroups.com> <mailto:ap-gto%40yahoogroups.com>

, "photonphisher" <parijat_singh@>

wrote:

Hi Ray, Howard,

The RA spike issue has come back again.

I have posted the ASCOM driver log here. The exact minute of time that it happened was 20:33 and 20:36.

http://tinyurl.com/78wpc42

Here is a snapshot of the guider log. The spike happens only in RA during guiding.

http://groups.yahoo.com/group/ap-gto/photos/album/104285095/pic/608492353/view

I have no idea what is going on.

Thanks for your help

Parijat



--- In ap-gto@... <mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> , "photonphisher" <parijat_singh@>

wrote:

I have been facing some strange guiding issues since some months and deferred posting here until I

could do

some experiments and narrow it down somewhat.

The issue happens only during guiding (not tracking) and it is this - A sharp spike in RA guiding graph of

+/- 5-

10 arcsec occurs periodic with the worm. Upon close observation, the symptom looks like tracking got turned

off

for a fraction of second and the guider brings the star back.

Here is what I know:

It only happens in RA. Does not matter if PEC on or off.
It only happens when guiding (I have tried Maxim, PHD) using ASCOM and not when using ST4.
It starts happening randomly and stops randomly for certain number of worm periods.
It seems to occur more frequently if I have Sky6 connected to the mount while autoguiding.
Crucially, if I turn on "Sync Pulse-guide" from the Driver, and disconnect TheSky6 from the mount, then it

does not happen. If I don't turn on sync pulseguide (driver default) and disconnect TheSky6, the issues

happens

but less frequently.

Without change to my hardware/software (other than AP drivers), this issue never occurred until perhaps

after

I updated to the driver a couple of releases ago (I am not sure which one).

So, I have ruled out mount mechanics, OTA mechanics (flexure), PEC, guider settings/calibration, hot

pixels.

Given the issue sensitivity to "sync pulseguide", I believe the issue is something to do with traffic/collision on

the

serial port to the mount and driver communication. I have not changed anything in TheSky6 or other

applications.

I tested the serial adapter/connectivity using Keyspan utility and and see no issues there.
Has anyone experienced this? Any clues to what could be going on?
I wanted to try reverting back to an old AP V2 driver; is there a link for that? I am afraid the "Sync

Pulseguide"

may not be optimal for low latency corrections to the mount.

Equipment: AP1200 GTO, C11 EdgeHD @f/10, Atik 314L+ imager and DSI I pro mono guider.

Thanks
Parijat

Another possibility is that the clutch was slipping so double check the scope's balance and/or the tightness of the RA
clutch knobs.

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: http://www.gralak.com/apdriver
Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

Hi Ray,
Having watched the star very closely when this occurs, I am very sure it is a brief stopping of tracking - the star rapidly moves 10's of pixels and is brought back again by presumably the guiding. It is quite obviously not hot pixel and not clutch slipping.
Note that during tracking-only, this does not happen. It only happens during guiding.

I am out of town currently so will check the spur gear. But I had recently checked it and it was quite tight. So what else could be happening?

Parijat

Hi Parijat,

Having watched the star very closely when this occurs, I am very sure it is a brief stopping of tracking - the star
rapidly moves 10's of pixels and is brought back again by presumably the guiding.

If tracking stopped the RA value would change but there is no indication of this in your log file. However, the RA does
change by exactly the right amount after each PulseGuide command is issued. As far as I can tell nothing changed the
tracking rate of your mount at the times of the incidents.

Note that during tracking-only, this does not happen. It only happens during guiding.

How can you be absolutely sure of this? The fact that you don't happen to see an instance of this happening doesn't
prove that it never happens.

I am out of town currently so will check the spur gear. But I had recently checked it and it was quite tight. So what
else could be happening?

A snagged cable, optics shifting, mount settling, etc. Maybe Roland will have other ideas but he and Marj are on their
way to NEAF so I'm not sure when he'll be able to respond.

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: http://www.gralak.com/apdriver
Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@... [mailto:ap-gto@...] On Behalf Of photonphisher
Sent: Tuesday, April 24, 2012 9:04 PM
To: ap-gto@...
Subject: [ap-gto] Re: Need help with issue in RA guiding and Synchronous Pulseguide



Hi Ray,
Having watched the star very closely when this occurs, I am very sure it is a brief stopping of tracking - the star
rapidly moves 10's of pixels and is brought back again by presumably the guiding. It is quite obviously not hot
pixel and not clutch slipping.
Note that during tracking-only, this does not happen. It only happens during guiding.

I am out of town currently so will check the spur gear. But I had recently checked it and it was quite tight. So what
else could be happening?

Parijat

--- In ap-gto@... <mailto:ap-gto%40yahoogroups.com> , "Ray Gralak" <groups1@...> wrote:

Another possibility is that the clutch was slipping so double check the scope's balance and/or the tightness of

the RA

clutch knobs.

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: http://www.gralak.com/apdriver
Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@... <mailto:ap-gto%40yahoogroups.com> [mailto:ap-gto@...

<mailto:ap-gto%40yahoogroups.com> ] On Behalf Of Ray Gralak

Sent: Tuesday, April 24, 2012 5:47 AM
To: ap-gto@... <mailto:ap-gto%40yahoogroups.com>
Subject: RE: [ap-gto] Re: Need help with issue in RA guiding and Synchronous Pulseguide



Hi Parijat,

Since I was auto-guiding, the star was brought back after the fast initial movement. So this 410ms is

probably

that.

Actually there were several big moves (all West) in a row. If tracking were stopped the change in RA

coordinates

would
not match up to the durations of the PulseGuide commands (but they do match up). Is it possible there was a
guide star
fade and the autoguider program was mistaking a hot pixel for a star?

Can you tell me what ASCOM command is to stop tracking for the GTOCP3? I was thinking of trying to

located

that in the serial I/O stream of the Keyspan utility.

You would see this command ":RT9#", without the double quotes.

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: http://www.gralak.com/apdriver
Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@... <mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> [mailto:ap-gto@... <mailto:ap-gto%40yahoogroups.com>

<mailto:ap-gto%40yahoogroups.com> ] On Behalf Of photonphisher

Sent: Tuesday, April 24, 2012 5:24 AM
To: ap-gto@... <mailto:ap-gto%40yahoogroups.com> <mailto:ap-gto%40yahoogroups.com>
Subject: [ap-gto] Re: Need help with issue in RA guiding and Synchronous Pulseguide



Hi Ray,
Since I was auto-guiding, the star was brought back after the fast initial movement. So this 410ms is

probably

that.
Last time I checked the spur gear, it was tight but will check again.
The weird thing is that this issue occurs randomly (e.g. sometimes occurs every period, other times does

not

occur for 4hrs) and more when TheSky6 is connected.
I would imagine with gear looseness, it would be less random.

Can you tell me what ASCOM command is to stop tracking for the GTOCP3? I was thinking of trying to

located

that in the serial I/O stream of the Keyspan utility.

Parijat

--- In ap-gto@... <mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-gto%40yahoogroups.com> ,

"Ray Gralak" <groups1@> wrote:

Hi Parijat,

I looked at your log file and I do not see anywhere that the mount was stopping. However, I do see a *big*

move

sent

from the autoguider program (410 mSecs). Have you checked for a loose spur gear in the motor box?

BIG move here (410 msecs West move)
019233 2012-04-22 20:32:58.609: ASCOM: Info : PulseGuide(3, 410)

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: http://www.gralak.com/apdriver
Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@... <mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> [mailto:ap-gto@... <mailto:ap-gto%40yahoogroups.com>

<mailto:ap-gto%40yahoogroups.com>

<mailto:ap-gto%40yahoogroups.com> ] On Behalf Of photonphisher

Sent: Monday, April 23, 2012 7:01 PM
To: ap-gto@... <mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-gto%40yahoogroups.com>

Subject: [ap-gto] Re: Need help with issue in RA guiding and Synchronous Pulseguide



Here is the fixed link to the ASCOM log file:
http://tech.groups.yahoo.com/group/ap-gto/files/photonphisher/

Parijat

--- In ap-gto@... <mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-gto%40yahoogroups.com>

, "photonphisher" <parijat_singh@>

wrote:

Hi Ray, Howard,

The RA spike issue has come back again.

I have posted the ASCOM driver log here. The exact minute of time that it happened was 20:33 and

20:36.

http://tinyurl.com/78wpc42

Here is a snapshot of the guider log. The spike happens only in RA during guiding.

http://groups.yahoo.com/group/ap-gto/photos/album/104285095/pic/608492353/view

I have no idea what is going on.

Thanks for your help

Parijat



--- In ap-gto@... <mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> , "photonphisher" <parijat_singh@>

wrote:

I have been facing some strange guiding issues since some months and deferred posting here until I

could do

some experiments and narrow it down somewhat.

The issue happens only during guiding (not tracking) and it is this - A sharp spike in RA guiding

graph of

+/- 5-

10 arcsec occurs periodic with the worm. Upon close observation, the symptom looks like tracking got

turned

off

for a fraction of second and the guider brings the star back.

Here is what I know:

It only happens in RA. Does not matter if PEC on or off.
It only happens when guiding (I have tried Maxim, PHD) using ASCOM and not when using ST4.
It starts happening randomly and stops randomly for certain number of worm periods.
It seems to occur more frequently if I have Sky6 connected to the mount while autoguiding.
Crucially, if I turn on "Sync Pulse-guide" from the Driver, and disconnect TheSky6 from the mount,

then

it

does not happen. If I don't turn on sync pulseguide (driver default) and disconnect TheSky6, the issues

happens

but less frequently.

Without change to my hardware/software (other than AP drivers), this issue never occurred until

perhaps

after

I updated to the driver a couple of releases ago (I am not sure which one).

So, I have ruled out mount mechanics, OTA mechanics (flexure), PEC, guider settings/calibration,

hot

pixels.

Given the issue sensitivity to "sync pulseguide", I believe the issue is something to do with

traffic/collision

on

the

serial port to the mount and driver communication. I have not changed anything in TheSky6 or other

applications.

I tested the serial adapter/connectivity using Keyspan utility and and see no issues there.
Has anyone experienced this? Any clues to what could be going on?
I wanted to try reverting back to an old AP V2 driver; is there a link for that? I am afraid the "Sync

Pulseguide"

may not be optimal for low latency corrections to the mount.

Equipment: AP1200 GTO, C11 EdgeHD @f/10, Atik 314L+ imager and DSI I pro mono guider.

Thanks
Parijat

Hi Parijat,

Ray may have brought a good point about optics shifting. If you are
using C-11 EdgeHD with autofocusing and not lock the mirror, mirror flop
might be the source of the problem. Even with OAG, the mirror shift
could have been big enough that OAG with guide camera could not catch
this quickly enough to correct it. 11" mirror is big and heavy and can
easily shift during tracking/guiding. Try imaging next time with the
mirror locked. I've had SCTs without mirror locks and mirror flops drove
me crazy until I got the EdgeHD.

Peter

--- In ap-gto@..., "Ray Gralak" <groups1@...> wrote:

Hi Parijat,

Having watched the star very closely when this occurs, I am very

sure it is a brief stopping of tracking - the star

rapidly moves 10's of pixels and is brought back again by presumably

the guiding.

If tracking stopped the RA value would change but there is no

indication of this in your log file. However, the RA does

change by exactly the right amount after each PulseGuide command is

issued. As far as I can tell nothing changed the

tracking rate of your mount at the times of the incidents.

Note that during tracking-only, this does not happen. It only

happens during guiding.

How can you be absolutely sure of this? The fact that you don't happen

to see an instance of this happening doesn't

prove that it never happens.

I am out of town currently so will check the spur gear. But I had

recently checked it and it was quite tight. So what

else could be happening?

A snagged cable, optics shifting, mount settling, etc. Maybe Roland

will have other ideas but he and Marj are on their

way to NEAF so I'm not sure when he'll be able to respond.

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver:

http://www.gralak.com/apdriver

Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@... [mailto:ap-gto@...] On

Behalf Of photonphisher

Sent: Tuesday, April 24, 2012 9:04 PM
To: ap-gto@...
Subject: [ap-gto] Re: Need help with issue in RA guiding and

Synchronous Pulseguide

Hi Ray,
Having watched the star very closely when this occurs, I am very

sure it is a brief stopping of tracking - the star

rapidly moves 10's of pixels and is brought back again by presumably

the guiding. It is quite obviously not hot

pixel and not clutch slipping.
Note that during tracking-only, this does not happen. It only

happens during guiding.

I am out of town currently so will check the spur gear. But I had

recently checked it and it was quite tight. So what

else could be happening?

Parijat

--- In ap-gto@... <mailto:ap-gto%40yahoogroups.com> ,

"Ray Gralak" groups1@ wrote:

Another possibility is that the clutch was slipping so double

check the scope's balance and/or the tightness of

the RA

clutch knobs.

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver:

http://www.gralak.com/apdriver

Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@... <mailto:ap-gto%40yahoogroups.com>

[mailto:ap-gto@...

<mailto:ap-gto%40yahoogroups.com> ] On Behalf Of Ray Gralak

Sent: Tuesday, April 24, 2012 5:47 AM
To: ap-gto@... <mailto:ap-gto%40yahoogroups.com>
Subject: RE: [ap-gto] Re: Need help with issue in RA guiding and

Synchronous Pulseguide

Hi Parijat,

Since I was auto-guiding, the star was brought back after the

fast initial movement. So this 410ms is

probably

that.

Actually there were several big moves (all West) in a row. If

tracking were stopped the change in RA

coordinates

would
not match up to the durations of the PulseGuide commands (but

they do match up). Is it possible there was a

guide star
fade and the autoguider program was mistaking a hot pixel for a

star?

Can you tell me what ASCOM command is to stop tracking for the

GTOCP3? I was thinking of trying to

located

that in the serial I/O stream of the Keyspan utility.

You would see this command ":RT9#", without the double quotes.

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver:

http://www.gralak.com/apdriver

Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@... <mailto:ap-gto%40yahoogroups.com>

<mailto:ap-

gto%40yahoogroups.com> [mailto:ap-gto@...

<mailto:ap-gto%40yahoogroups.com>

<mailto:ap-gto%40yahoogroups.com> ] On Behalf Of photonphisher

Sent: Tuesday, April 24, 2012 5:24 AM
To: ap-gto@... <mailto:ap-gto%40yahoogroups.com>

<mailto:ap-gto%40yahoogroups.com>

Subject: [ap-gto] Re: Need help with issue in RA guiding and

Synchronous Pulseguide

Hi Ray,
Since I was auto-guiding, the star was brought back after the

fast initial movement. So this 410ms is

probably

that.
Last time I checked the spur gear, it was tight but will check

again.

The weird thing is that this issue occurs randomly (e.g.

sometimes occurs every period, other times does

not

occur for 4hrs) and more when TheSky6 is connected.
I would imagine with gear looseness, it would be less random.

Can you tell me what ASCOM command is to stop tracking for the

GTOCP3? I was thinking of trying to

located

that in the serial I/O stream of the Keyspan utility.

Parijat

--- In ap-gto@...

<mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-gto%40yahoogroups.com> ,

"Ray Gralak" <groups1@> wrote:

Hi Parijat,

I looked at your log file and I do not see anywhere that the

mount was stopping. However, I do see a *big*

move

sent

from the autoguider program (410 mSecs). Have you checked

for a loose spur gear in the motor box?

BIG move here (410 msecs West move)
019233 2012-04-22 20:32:58.609: ASCOM: Info : PulseGuide(3,

410)

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver:

http://www.gralak.com/apdriver

Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@...

<mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> [mailto:ap-gto@...

<mailto:ap-gto%40yahoogroups.com>

<mailto:ap-gto%40yahoogroups.com>

<mailto:ap-gto%40yahoogroups.com> ] On Behalf Of photonphisher

Sent: Monday, April 23, 2012 7:01 PM
To: ap-gto@...

<mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-gto%40yahoogroups.com>

Subject: [ap-gto] Re: Need help with issue in RA guiding

and Synchronous Pulseguide

Here is the fixed link to the ASCOM log file:

http://tech.groups.yahoo.com/group/ap-gto/files/photonphisher/

Parijat

--- In ap-gto@...

<mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-gto%40yahoogroups.com>

, "photonphisher" <parijat_singh@>

wrote:

Hi Ray, Howard,

The RA spike issue has come back again.

I have posted the ASCOM driver log here. The exact

minute of time that it happened was 20:33 and

20:36.

http://tinyurl.com/78wpc42

Here is a snapshot of the guider log. The spike happens

only in RA during guiding.

http://groups.yahoo.com/group/ap-gto/photos/album/104285095/pic/60849235\;
3/view

I have no idea what is going on.

Thanks for your help

Parijat



--- In ap-gto@...

<mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> , "photonphisher" <parijat_singh@>

wrote:

I have been facing some strange guiding issues since

some months and deferred posting here until I

could do

some experiments and narrow it down somewhat.

The issue happens only during guiding (not tracking)

and it is this - A sharp spike in RA guiding

graph of

+/- 5-

10 arcsec occurs periodic with the worm. Upon close

observation, the symptom looks like tracking got

turned

off

for a fraction of second and the guider brings the star

back.

Here is what I know:

It only happens in RA. Does not matter if PEC on or

off.

It only happens when guiding (I have tried Maxim, PHD)

using ASCOM and not when using ST4.

It starts happening randomly and stops randomly for

certain number of worm periods.

It seems to occur more frequently if I have Sky6

connected to the mount while autoguiding.

Crucially, if I turn on "Sync Pulse-guide" from the

Driver, and disconnect TheSky6 from the mount,

then

it

does not happen. If I don't turn on sync pulseguide

(driver default) and disconnect TheSky6, the issues

happens

but less frequently.

Without change to my hardware/software (other than AP

drivers), this issue never occurred until

perhaps

after

I updated to the driver a couple of releases ago (I am not

sure which one).

So, I have ruled out mount mechanics, OTA mechanics

(flexure), PEC, guider settings/calibration,

hot

pixels.

Given the issue sensitivity to "sync pulseguide", I

believe the issue is something to do with

traffic/collision

on

the

serial port to the mount and driver communication. I have

not changed anything in TheSky6 or other

applications.

I tested the serial adapter/connectivity using Keyspan

utility and and see no issues there.

Has anyone experienced this? Any clues to what could

be going on?

I wanted to try reverting back to an old AP V2 driver;

is there a link for that? I am afraid the "Sync

Pulseguide"

may not be optimal for low latency corrections to the

mount.

Equipment: AP1200 GTO, C11 EdgeHD @f/10, Atik 314L+

imager and DSI I pro mono guider.

Thanks
Parijat

Hi Ray,
Thanks for your inputs.

If tracking stopped the RA value would change but there is no indication of this in your log file. However, the RA does
change by exactly the right amount after each PulseGuide command is issued. As far as I can tell nothing changed the
tracking rate of your mount at the times of the incidents.

Will the ASCOM log contain *all* information on brief tracking stopping (even if the driver did not initiate it)?

If you see the star behavior I saw, you would immediately think it is tracking stopping....that is how obvious it was. There is no other way I could explain a very rapid movement of star *only* in RA of several arc-seconds.

How can you be absolutely sure of this? The fact that you don't happen to see an instance of this happening doesn't
prove that it never happens.

No I am not absolutely sure and I can never prove it never happens during tracking. However, In my experiments, when I see it happening at every period, I turn off guiding and does not happen. Turn it back on, and it starts happening. I never saw it happen during tracking and always during guding. So I believe this data has some significance.

A snagged cable, optics shifting, mount settling,

I have ruled those out due to (1) happens *only* in RA - optics/flexure/cables/vibrations don't care about RA/DEC (2) the movement is quite large and sharp and behavior is much more easily explained by tracking stopping than slow effects like the above.

Do you think collisions of serial async data traffic can cause corruption of commands and possibly cause this?
The only other thing I can think of is loose spur gear that I will check. But the randomness of this is puzzling.

Parijat

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: http://www.gralak.com/apdriver
Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@... [mailto:ap-gto@...] On Behalf Of photonphisher
Sent: Tuesday, April 24, 2012 9:04 PM
To: ap-gto@...
Subject: [ap-gto] Re: Need help with issue in RA guiding and Synchronous Pulseguide



Hi Ray,
Having watched the star very closely when this occurs, I am very sure it is a brief stopping of tracking - the star
rapidly moves 10's of pixels and is brought back again by presumably the guiding. It is quite obviously not hot
pixel and not clutch slipping.
Note that during tracking-only, this does not happen. It only happens during guiding.

I am out of town currently so will check the spur gear. But I had recently checked it and it was quite tight. So what
else could be happening?

Parijat

--- In ap-gto@... <mailto:ap-gto%40yahoogroups.com> , "Ray Gralak" <groups1@> wrote:

Another possibility is that the clutch was slipping so double check the scope's balance and/or the tightness of

the RA

clutch knobs.

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: http://www.gralak.com/apdriver
Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@... <mailto:ap-gto%40yahoogroups.com> [mailto:ap-gto@...

<mailto:ap-gto%40yahoogroups.com> ] On Behalf Of Ray Gralak

Sent: Tuesday, April 24, 2012 5:47 AM
To: ap-gto@... <mailto:ap-gto%40yahoogroups.com>
Subject: RE: [ap-gto] Re: Need help with issue in RA guiding and Synchronous Pulseguide



Hi Parijat,

Since I was auto-guiding, the star was brought back after the fast initial movement. So this 410ms is

probably

that.

Actually there were several big moves (all West) in a row. If tracking were stopped the change in RA

coordinates

would
not match up to the durations of the PulseGuide commands (but they do match up). Is it possible there was a
guide star
fade and the autoguider program was mistaking a hot pixel for a star?

Can you tell me what ASCOM command is to stop tracking for the GTOCP3? I was thinking of trying to

located

that in the serial I/O stream of the Keyspan utility.

You would see this command ":RT9#", without the double quotes.

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: http://www.gralak.com/apdriver
Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@... <mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> [mailto:ap-gto@... <mailto:ap-gto%40yahoogroups.com>

<mailto:ap-gto%40yahoogroups.com> ] On Behalf Of photonphisher

Sent: Tuesday, April 24, 2012 5:24 AM
To: ap-gto@... <mailto:ap-gto%40yahoogroups.com> <mailto:ap-gto%40yahoogroups.com>
Subject: [ap-gto] Re: Need help with issue in RA guiding and Synchronous Pulseguide



Hi Ray,
Since I was auto-guiding, the star was brought back after the fast initial movement. So this 410ms is

probably

that.
Last time I checked the spur gear, it was tight but will check again.
The weird thing is that this issue occurs randomly (e.g. sometimes occurs every period, other times does

not

occur for 4hrs) and more when TheSky6 is connected.
I would imagine with gear looseness, it would be less random.

Can you tell me what ASCOM command is to stop tracking for the GTOCP3? I was thinking of trying to

located

that in the serial I/O stream of the Keyspan utility.

Parijat

--- In ap-gto@... <mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-gto%40yahoogroups.com> ,

"Ray Gralak" <groups1@> wrote:

Hi Parijat,

I looked at your log file and I do not see anywhere that the mount was stopping. However, I do see a *big*

move

sent

from the autoguider program (410 mSecs). Have you checked for a loose spur gear in the motor box?

BIG move here (410 msecs West move)
019233 2012-04-22 20:32:58.609: ASCOM: Info : PulseGuide(3, 410)

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: http://www.gralak.com/apdriver
Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@... <mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> [mailto:ap-gto@... <mailto:ap-gto%40yahoogroups.com>

<mailto:ap-gto%40yahoogroups.com>

<mailto:ap-gto%40yahoogroups.com> ] On Behalf Of photonphisher

Sent: Monday, April 23, 2012 7:01 PM
To: ap-gto@... <mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-gto%40yahoogroups.com>

Subject: [ap-gto] Re: Need help with issue in RA guiding and Synchronous Pulseguide



Here is the fixed link to the ASCOM log file:
http://tech.groups.yahoo.com/group/ap-gto/files/photonphisher/

Parijat

--- In ap-gto@... <mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-gto%40yahoogroups.com>

, "photonphisher" <parijat_singh@>

wrote:

Hi Ray, Howard,

The RA spike issue has come back again.

I have posted the ASCOM driver log here. The exact minute of time that it happened was 20:33 and

20:36.

http://tinyurl.com/78wpc42

Here is a snapshot of the guider log. The spike happens only in RA during guiding.

http://groups.yahoo.com/group/ap-gto/photos/album/104285095/pic/608492353/view

I have no idea what is going on.

Thanks for your help

Parijat



--- In ap-gto@... <mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> , "photonphisher" <parijat_singh@>

wrote:

I have been facing some strange guiding issues since some months and deferred posting here until I

could do

some experiments and narrow it down somewhat.

The issue happens only during guiding (not tracking) and it is this - A sharp spike in RA guiding

graph of

+/- 5-

10 arcsec occurs periodic with the worm. Upon close observation, the symptom looks like tracking got

turned

off

for a fraction of second and the guider brings the star back.

Here is what I know:

It only happens in RA. Does not matter if PEC on or off.
It only happens when guiding (I have tried Maxim, PHD) using ASCOM and not when using ST4.
It starts happening randomly and stops randomly for certain number of worm periods.
It seems to occur more frequently if I have Sky6 connected to the mount while autoguiding.
Crucially, if I turn on "Sync Pulse-guide" from the Driver, and disconnect TheSky6 from the mount,

then

it

does not happen. If I don't turn on sync pulseguide (driver default) and disconnect TheSky6, the issues

happens

but less frequently.

Without change to my hardware/software (other than AP drivers), this issue never occurred until

perhaps

after

I updated to the driver a couple of releases ago (I am not sure which one).

So, I have ruled out mount mechanics, OTA mechanics (flexure), PEC, guider settings/calibration,

hot

pixels.

Given the issue sensitivity to "sync pulseguide", I believe the issue is something to do with

traffic/collision

on

the

serial port to the mount and driver communication. I have not changed anything in TheSky6 or other

applications.

I tested the serial adapter/connectivity using Keyspan utility and and see no issues there.
Has anyone experienced this? Any clues to what could be going on?
I wanted to try reverting back to an old AP V2 driver; is there a link for that? I am afraid the "Sync

Pulseguide"

may not be optimal for low latency corrections to the mount.

Equipment: AP1200 GTO, C11 EdgeHD @f/10, Atik 314L+ imager and DSI I pro mono guider.

Thanks
Parijat

Hi Parijat,

I have read reports that mirror flops typically happens in RA since the
mount moves only in RA. Did the issue happened when crossing the
Meridian because that's when the biggest mirror flop can happen?

Peter

--- In ap-gto@..., "photonphisher" <parijat_singh@...>
wrote:

Hi Ray,
Thanks for your inputs.

If tracking stopped the RA value would change but there is no

indication of this in your log file. However, the RA does

change by exactly the right amount after each PulseGuide command is

issued. As far as I can tell nothing changed the

tracking rate of your mount at the times of the incidents.

Will the ASCOM log contain *all* information on brief tracking

stopping (even if the driver did not initiate it)?

If you see the star behavior I saw, you would immediately think it is

tracking stopping....that is how obvious it was. There is no other way I
could explain a very rapid movement of star *only* in RA of several
arc-seconds.

How can you be absolutely sure of this? The fact that you don't

happen to see an instance of this happening doesn't

prove that it never happens.

No I am not absolutely sure and I can never prove it never happens

during tracking. However, In my experiments, when I see it happening at
every period, I turn off guiding and does not happen. Turn it back on,
and it starts happening. I never saw it happen during tracking and
always during guding. So I believe this data has some significance.

A snagged cable, optics shifting, mount settling,

I have ruled those out due to (1) happens *only* in RA -

optics/flexure/cables/vibrations don't care about RA/DEC (2) the
movement is quite large and sharp and behavior is much more easily
explained by tracking stopping than slow effects like the above.

Do you think collisions of serial async data traffic can cause

corruption of commands and possibly cause this?

The only other thing I can think of is loose spur gear that I will

check. But the randomness of this is puzzling.

Parijat

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver:

http://www.gralak.com/apdriver

Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@... [mailto:ap-gto@...] On

Behalf Of photonphisher

Sent: Tuesday, April 24, 2012 9:04 PM
To: ap-gto@...
Subject: [ap-gto] Re: Need help with issue in RA guiding and

Synchronous Pulseguide

Hi Ray,
Having watched the star very closely when this occurs, I am very

sure it is a brief stopping of tracking - the star

rapidly moves 10's of pixels and is brought back again by

presumably the guiding. It is quite obviously not hot

pixel and not clutch slipping.
Note that during tracking-only, this does not happen. It only

happens during guiding.

I am out of town currently so will check the spur gear. But I had

recently checked it and it was quite tight. So what

else could be happening?

Parijat

--- In ap-gto@... <mailto:ap-gto%40yahoogroups.com> ,

"Ray Gralak" <groups1@> wrote:

Another possibility is that the clutch was slipping so double

check the scope's balance and/or the tightness of

the RA

clutch knobs.

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver:

http://www.gralak.com/apdriver

Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@... <mailto:ap-gto%40yahoogroups.com>

[mailto:ap-gto@...

<mailto:ap-gto%40yahoogroups.com> ] On Behalf Of Ray Gralak

Sent: Tuesday, April 24, 2012 5:47 AM
To: ap-gto@... <mailto:ap-gto%40yahoogroups.com>
Subject: RE: [ap-gto] Re: Need help with issue in RA guiding

and Synchronous Pulseguide

Hi Parijat,

Since I was auto-guiding, the star was brought back after

the fast initial movement. So this 410ms is

probably

that.

Actually there were several big moves (all West) in a row. If

tracking were stopped the change in RA

coordinates

would
not match up to the durations of the PulseGuide commands (but

they do match up). Is it possible there was a

guide star
fade and the autoguider program was mistaking a hot pixel for

a star?

Can you tell me what ASCOM command is to stop tracking for

the GTOCP3? I was thinking of trying to

located

that in the serial I/O stream of the Keyspan utility.

You would see this command ":RT9#", without the double quotes.

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver:

http://www.gralak.com/apdriver

Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@...

<mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> [mailto:ap-gto@...

<mailto:ap-gto%40yahoogroups.com>

<mailto:ap-gto%40yahoogroups.com> ] On Behalf Of photonphisher

Sent: Tuesday, April 24, 2012 5:24 AM
To: ap-gto@... <mailto:ap-gto%40yahoogroups.com>

<mailto:ap-gto%40yahoogroups.com>

Subject: [ap-gto] Re: Need help with issue in RA guiding and

Synchronous Pulseguide

Hi Ray,
Since I was auto-guiding, the star was brought back after

the fast initial movement. So this 410ms is

probably

that.
Last time I checked the spur gear, it was tight but will

check again.

The weird thing is that this issue occurs randomly (e.g.

sometimes occurs every period, other times does

not

occur for 4hrs) and more when TheSky6 is connected.
I would imagine with gear looseness, it would be less

random.

Can you tell me what ASCOM command is to stop tracking for

the GTOCP3? I was thinking of trying to

located

that in the serial I/O stream of the Keyspan utility.

Parijat

--- In ap-gto@...

<mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-gto%40yahoogroups.com> ,

"Ray Gralak" <groups1@> wrote:

Hi Parijat,

I looked at your log file and I do not see anywhere that

the mount was stopping. However, I do see a *big*

move

sent

from the autoguider program (410 mSecs). Have you checked

for a loose spur gear in the motor box?

BIG move here (410 msecs West move)
019233 2012-04-22 20:32:58.609: ASCOM: Info :

PulseGuide(3, 410)

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver:

http://www.gralak.com/apdriver

Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@...

<mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> [mailto:ap-gto@...

<mailto:ap-gto%40yahoogroups.com>

<mailto:ap-gto%40yahoogroups.com>

<mailto:ap-gto%40yahoogroups.com> ] On Behalf Of

photonphisher

Sent: Monday, April 23, 2012 7:01 PM
To: ap-gto@...

<mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-gto%40yahoogroups.com>

Subject: [ap-gto] Re: Need help with issue in RA guiding

and Synchronous Pulseguide

Here is the fixed link to the ASCOM log file:

http://tech.groups.yahoo.com/group/ap-gto/files/photonphisher/

Parijat

--- In ap-gto@...

<mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-gto%40yahoogroups.com>

, "photonphisher" <parijat_singh@>

wrote:

Hi Ray, Howard,

The RA spike issue has come back again.

I have posted the ASCOM driver log here. The exact

minute of time that it happened was 20:33 and

20:36.

http://tinyurl.com/78wpc42

Here is a snapshot of the guider log. The spike

happens only in RA during guiding.

http://groups.yahoo.com/group/ap-gto/photos/album/104285095/pic/60849235\;
3/view

I have no idea what is going on.

Thanks for your help

Parijat



--- In ap-gto@...

<mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> , "photonphisher" <parijat_singh@>

wrote:

I have been facing some strange guiding issues since

some months and deferred posting here until I

could do

some experiments and narrow it down somewhat.

The issue happens only during guiding (not tracking)

and it is this - A sharp spike in RA guiding

graph of

+/- 5-

10 arcsec occurs periodic with the worm. Upon close

observation, the symptom looks like tracking got

turned

off

for a fraction of second and the guider brings the star

back.

Here is what I know:

It only happens in RA. Does not matter if PEC on or

off.

It only happens when guiding (I have tried Maxim,

PHD) using ASCOM and not when using ST4.

It starts happening randomly and stops randomly for

certain number of worm periods.

It seems to occur more frequently if I have Sky6

connected to the mount while autoguiding.

Crucially, if I turn on "Sync Pulse-guide" from the

Driver, and disconnect TheSky6 from the mount,

then

it

does not happen. If I don't turn on sync pulseguide

(driver default) and disconnect TheSky6, the issues

happens

but less frequently.

Without change to my hardware/software (other than

AP drivers), this issue never occurred until

perhaps

after

I updated to the driver a couple of releases ago (I am

not sure which one).

So, I have ruled out mount mechanics, OTA mechanics

(flexure), PEC, guider settings/calibration,

hot

pixels.

Given the issue sensitivity to "sync pulseguide", I

believe the issue is something to do with

traffic/collision

on

the

serial port to the mount and driver communication. I

have not changed anything in TheSky6 or other

applications.

I tested the serial adapter/connectivity using

Keyspan utility and and see no issues there.

Has anyone experienced this? Any clues to what could

be going on?

I wanted to try reverting back to an old AP V2

driver; is there a link for that? I am afraid the "Sync

Pulseguide"

may not be optimal for low latency corrections to the

mount.

Equipment: AP1200 GTO, C11 EdgeHD @f/10, Atik 314L+

imager and DSI I pro mono guider.

Thanks
Parijat

Hi Parijat,

Will the ASCOM log contain *all* information on brief tracking stopping (even if the driver did not initiate it)?

Yes, absolutely. For this type of issue all that is needed is the Right Ascension value, which the driver polls once per
second.

For instance, if RA is stopped for even 1/10th of a second the RA value would show a change of 0.1 arc-seconds. It would
not matter what caused the change (e.g. PulseGuide moves, autoguider port moves, button pushes on the hand controller,
etc.) because the RA read back value would tell if there was a movement from any and all sources.

Plus, even if tracking was stopped, restarted, then the autoguider brought the star back to center the resulting RA
value would be exactly what it was before tracking was stopped (because the RA value of the star does not change!). But
in your log it shows that RA changed and stayed changed thus proving RA did not stop tracking. Thus something external
to the mount must have caused the star to "move".

If you see the star behavior I saw, you would immediately think it is tracking stopping....that is how obvious it was.
There is no other way I could explain a very rapid movement of star *only* in RA of several arc-seconds

There is, actually, and I've had it happen to me several times. It happened to me when the RA clutch slipped. Even if
the RA clutch is tight the clutch can slip if there is enough weight imbalance. That was exactly my scenario!

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: http://www.gralak.com/apdriver
Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@... [mailto:ap-gto@...] On Behalf Of photonphisher
Sent: Wednesday, April 25, 2012 7:41 AM
To: ap-gto@...
Subject: [ap-gto] Re: Need help with issue in RA guiding and Synchronous Pulseguide





Hi Ray,
Thanks for your inputs.

If tracking stopped the RA value would change but there is no indication of this in your log file. However, the RA

does

change by exactly the right amount after each PulseGuide command is issued. As far as I can tell nothing

changed the

tracking rate of your mount at the times of the incidents.

Will the ASCOM log contain *all* information on brief tracking stopping (even if the driver did not initiate it)?

If you see the star behavior I saw, you would immediately think it is tracking stopping....that is how obvious it was.
There is no other way I could explain a very rapid movement of star *only* in RA of several arc-seconds.

How can you be absolutely sure of this? The fact that you don't happen to see an instance of this happening

doesn't

prove that it never happens.

No I am not absolutely sure and I can never prove it never happens during tracking. However, In my experiments,
when I see it happening at every period, I turn off guiding and does not happen. Turn it back on, and it starts
happening. I never saw it happen during tracking and always during guding. So I believe this data has some
significance.

A snagged cable, optics shifting, mount settling,

I have ruled those out due to (1) happens *only* in RA - optics/flexure/cables/vibrations don't care about RA/DEC
(2) the movement is quite large and sharp and behavior is much more easily explained by tracking stopping than
slow effects like the above.

Do you think collisions of serial async data traffic can cause corruption of commands and possibly cause this?
The only other thing I can think of is loose spur gear that I will check. But the randomness of this is puzzling.

Parijat

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: http://www.gralak.com/apdriver
Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@... <mailto:ap-gto%40yahoogroups.com> [mailto:ap-gto@...

<mailto:ap-gto%40yahoogroups.com> ] On Behalf Of photonphisher

Sent: Tuesday, April 24, 2012 9:04 PM
To: ap-gto@... <mailto:ap-gto%40yahoogroups.com>
Subject: [ap-gto] Re: Need help with issue in RA guiding and Synchronous Pulseguide



Hi Ray,
Having watched the star very closely when this occurs, I am very sure it is a brief stopping of tracking - the

star

rapidly moves 10's of pixels and is brought back again by presumably the guiding. It is quite obviously not hot
pixel and not clutch slipping.
Note that during tracking-only, this does not happen. It only happens during guiding.

I am out of town currently so will check the spur gear. But I had recently checked it and it was quite tight. So

what

else could be happening?

Parijat

--- In ap-gto@... <mailto:ap-gto%40yahoogroups.com> <mailto:ap-gto%40yahoogroups.com>

, "Ray Gralak" <groups1@> wrote:

Another possibility is that the clutch was slipping so double check the scope's balance and/or the tightness

of

the RA

clutch knobs.

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: http://www.gralak.com/apdriver
Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@... <mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> [mailto:ap-gto@... <mailto:ap-gto%40yahoogroups.com>

<mailto:ap-gto%40yahoogroups.com> ] On Behalf Of Ray Gralak

Sent: Tuesday, April 24, 2012 5:47 AM
To: ap-gto@... <mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com>

Subject: RE: [ap-gto] Re: Need help with issue in RA guiding and Synchronous Pulseguide



Hi Parijat,

Since I was auto-guiding, the star was brought back after the fast initial movement. So this 410ms is

probably

that.

Actually there were several big moves (all West) in a row. If tracking were stopped the change in RA

coordinates

would
not match up to the durations of the PulseGuide commands (but they do match up). Is it possible there

was a

guide star
fade and the autoguider program was mistaking a hot pixel for a star?

Can you tell me what ASCOM command is to stop tracking for the GTOCP3? I was thinking of trying to

located

that in the serial I/O stream of the Keyspan utility.

You would see this command ":RT9#", without the double quotes.

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: http://www.gralak.com/apdriver
Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@... <mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> [mailto:ap-gto@... <mailto:ap-gto%40yahoogroups.com>

<mailto:ap-gto%40yahoogroups.com>

<mailto:ap-gto%40yahoogroups.com> ] On Behalf Of photonphisher

Sent: Tuesday, April 24, 2012 5:24 AM
To: ap-gto@... <mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-gto%40yahoogroups.com>

Subject: [ap-gto] Re: Need help with issue in RA guiding and Synchronous Pulseguide



Hi Ray,
Since I was auto-guiding, the star was brought back after the fast initial movement. So this 410ms is

probably

that.
Last time I checked the spur gear, it was tight but will check again.
The weird thing is that this issue occurs randomly (e.g. sometimes occurs every period, other times

does

not

occur for 4hrs) and more when TheSky6 is connected.
I would imagine with gear looseness, it would be less random.

Can you tell me what ASCOM command is to stop tracking for the GTOCP3? I was thinking of trying to

located

that in the serial I/O stream of the Keyspan utility.

Parijat

--- In ap-gto@... <mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-gto%40yahoogroups.com> ,

"Ray Gralak" <groups1@> wrote:

Hi Parijat,

I looked at your log file and I do not see anywhere that the mount was stopping. However, I do see a

*big*

move

sent

from the autoguider program (410 mSecs). Have you checked for a loose spur gear in the motor box?

BIG move here (410 msecs West move)
019233 2012-04-22 20:32:58.609: ASCOM: Info : PulseGuide(3, 410)

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: http://www.gralak.com/apdriver
Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@... <mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> [mailto:ap-gto@... <mailto:ap-gto%40yahoogroups.com>

<mailto:ap-gto%40yahoogroups.com>

<mailto:ap-gto%40yahoogroups.com>

<mailto:ap-gto%40yahoogroups.com> ] On Behalf Of photonphisher

Sent: Monday, April 23, 2012 7:01 PM
To: ap-gto@... <mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-gto%40yahoogroups.com>

Subject: [ap-gto] Re: Need help with issue in RA guiding and Synchronous Pulseguide



Here is the fixed link to the ASCOM log file:
http://tech.groups.yahoo.com/group/ap-gto/files/photonphisher/

Parijat

--- In ap-gto@... <mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-gto%40yahoogroups.com>

, "photonphisher" <parijat_singh@>

wrote:

Hi Ray, Howard,

The RA spike issue has come back again.

I have posted the ASCOM driver log here. The exact minute of time that it happened was 20:33

and

20:36.

http://tinyurl.com/78wpc42

Here is a snapshot of the guider log. The spike happens only in RA during guiding.

http://groups.yahoo.com/group/ap-gto/photos/album/104285095/pic/608492353/view

I have no idea what is going on.

Thanks for your help

Parijat



--- In ap-gto@... <mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> , "photonphisher" <parijat_singh@>

wrote:

I have been facing some strange guiding issues since some months and deferred posting here

until I

could do

some experiments and narrow it down somewhat.

The issue happens only during guiding (not tracking) and it is this - A sharp spike in RA guiding

graph of

+/- 5-

10 arcsec occurs periodic with the worm. Upon close observation, the symptom looks like tracking

got

turned

off

for a fraction of second and the guider brings the star back.

Here is what I know:

It only happens in RA. Does not matter if PEC on or off.
It only happens when guiding (I have tried Maxim, PHD) using ASCOM and not when using ST4.
It starts happening randomly and stops randomly for certain number of worm periods.
It seems to occur more frequently if I have Sky6 connected to the mount while autoguiding.
Crucially, if I turn on "Sync Pulse-guide" from the Driver, and disconnect TheSky6 from the

mount,

then

it

does not happen. If I don't turn on sync pulseguide (driver default) and disconnect TheSky6, the

issues

happens

but less frequently.

Without change to my hardware/software (other than AP drivers), this issue never occurred until

perhaps

after

I updated to the driver a couple of releases ago (I am not sure which one).

So, I have ruled out mount mechanics, OTA mechanics (flexure), PEC, guider

settings/calibration,

hot

pixels.

Given the issue sensitivity to "sync pulseguide", I believe the issue is something to do with

traffic/collision

on

the

serial port to the mount and driver communication. I have not changed anything in TheSky6 or other

applications.

I tested the serial adapter/connectivity using Keyspan utility and and see no issues there.
Has anyone experienced this? Any clues to what could be going on?
I wanted to try reverting back to an old AP V2 driver; is there a link for that? I am afraid the

"Sync

Pulseguide"

may not be optimal for low latency corrections to the mount.

Equipment: AP1200 GTO, C11 EdgeHD @f/10, Atik 314L+ imager and DSI I pro mono guider.

Thanks
Parijat

Hi Peter,
It does not happen only at zenith...happens low or high, kinda random.
Also, the issue has almost zero component of movement in DEC. So I think it is not related to mirror flop.


Parijat

Hi Ray,

Those are all very good points - much appreciated. Gives me something to narrow down the issue.

I have always carefully balanced the mount and kept quite tight clutches. But I will check again this weekend. I am pretty sure the cause it external to the mount (I mentioned this in my first post), however trying to find out where it can be.

The data point about tracking vs. guiding is what is confusing me. The obvious things (which you also mentioned) does not explain this difference in behavior.

Parijat

Hi Parijat,

Have you owned the mount for a long time or did you buy it used? The
reason I asked is I've read that people replaced the clutches even
though they felt tight but they were still slipping. These clutches do
wear out but I don't know what their life cycle is. You might want to
remove the clutches for inspection. I have no idea what a worn out
clutches look like.

Peter

--- In ap-gto@..., "photonphisher" <parijat_singh@...>
wrote:

Hi Ray,

Those are all very good points - much appreciated. Gives me something

to narrow down the issue.

I have always carefully balanced the mount and kept quite tight

clutches. But I will check again this weekend. I am pretty sure the
cause it external to the mount (I mentioned this in my first post),
however trying to find out where it can be.

The data point about tracking vs. guiding is what is confusing me. The

obvious things (which you also mentioned) does not explain this
difference in behavior.

Parijat


--- In ap-gto@..., "Ray Gralak" groups1@ wrote:

Hi Parijat,

Will the ASCOM log contain *all* information on brief tracking

stopping (even if the driver did not initiate it)?

Yes, absolutely. For this type of issue all that is needed is the

Right Ascension value, which the driver polls once per

second.

For instance, if RA is stopped for even 1/10th of a second the RA

value would show a change of 0.1 arc-seconds. It would

not matter what caused the change (e.g. PulseGuide moves, autoguider

port moves, button pushes on the hand controller,

etc.) because the RA read back value would tell if there was a

movement from any and all sources.

Plus, even if tracking was stopped, restarted, then the autoguider

brought the star back to center the resulting RA

value would be exactly what it was before tracking was stopped

(because the RA value of the star does not change!). But

in your log it shows that RA changed and stayed changed thus proving

RA did not stop tracking. Thus something external

to the mount must have caused the star to "move".

If you see the star behavior I saw, you would immediately think it

is tracking stopping....that is how obvious it was.

There is no other way I could explain a very rapid movement of

star *only* in RA of several arc-seconds

There is, actually, and I've had it happen to me several times. It

happened to me when the RA clutch slipped. Even if

the RA clutch is tight the clutch can slip if there is enough weight

imbalance. That was exactly my scenario!

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver:

http://www.gralak.com/apdriver

Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@... [mailto:ap-gto@...] On

Behalf Of photonphisher

Sent: Wednesday, April 25, 2012 7:41 AM
To: ap-gto@...
Subject: [ap-gto] Re: Need help with issue in RA guiding and

Synchronous Pulseguide

Hi Ray,
Thanks for your inputs.

If tracking stopped the RA value would change but there is no

indication of this in your log file. However, the RA

does

change by exactly the right amount after each PulseGuide command

is issued. As far as I can tell nothing

changed the

tracking rate of your mount at the times of the incidents.

Will the ASCOM log contain *all* information on brief tracking

stopping (even if the driver did not initiate it)?

If you see the star behavior I saw, you would immediately think it

is tracking stopping....that is how obvious it was.

There is no other way I could explain a very rapid movement of

star *only* in RA of several arc-seconds.

How can you be absolutely sure of this? The fact that you don't

happen to see an instance of this happening

doesn't

prove that it never happens.

No I am not absolutely sure and I can never prove it never happens

during tracking. However, In my experiments,

when I see it happening at every period, I turn off guiding and

does not happen. Turn it back on, and it starts

happening. I never saw it happen during tracking and always during

guding. So I believe this data has some

significance.

A snagged cable, optics shifting, mount settling,

I have ruled those out due to (1) happens *only* in RA -

optics/flexure/cables/vibrations don't care about RA/DEC

(2) the movement is quite large and sharp and behavior is much

more easily explained by tracking stopping than

slow effects like the above.

Do you think collisions of serial async data traffic can cause

corruption of commands and possibly cause this?

The only other thing I can think of is loose spur gear that I will

check. But the randomness of this is puzzling.

Parijat

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver:

http://www.gralak.com/apdriver

Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@... <mailto:ap-gto%40yahoogroups.com>

[mailto:ap-gto@...

<mailto:ap-gto%40yahoogroups.com> ] On Behalf Of photonphisher

Sent: Tuesday, April 24, 2012 9:04 PM
To: ap-gto@... <mailto:ap-gto%40yahoogroups.com>
Subject: [ap-gto] Re: Need help with issue in RA guiding and

Synchronous Pulseguide

Hi Ray,
Having watched the star very closely when this occurs, I am

very sure it is a brief stopping of tracking - the

star

rapidly moves 10's of pixels and is brought back again by

presumably the guiding. It is quite obviously not hot

pixel and not clutch slipping.
Note that during tracking-only, this does not happen. It only

happens during guiding.

I am out of town currently so will check the spur gear. But I

had recently checked it and it was quite tight. So

what

else could be happening?

Parijat

--- In ap-gto@...

<mailto:ap-gto%40yahoogroups.com> <mailto:ap-gto%40yahoogroups.com>

, "Ray Gralak" <groups1@> wrote:

Another possibility is that the clutch was slipping so

double check the scope's balance and/or the tightness

of

the RA

clutch knobs.

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver:

http://www.gralak.com/apdriver

Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@...

<mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> [mailto:ap-gto@...

<mailto:ap-gto%40yahoogroups.com>

<mailto:ap-gto%40yahoogroups.com> ] On Behalf Of Ray Gralak

Sent: Tuesday, April 24, 2012 5:47 AM
To: ap-gto@...

<mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com>

Subject: RE: [ap-gto] Re: Need help with issue in RA

guiding and Synchronous Pulseguide

Hi Parijat,

Since I was auto-guiding, the star was brought back

after the fast initial movement. So this 410ms is

probably

that.

Actually there were several big moves (all West) in a row.

If tracking were stopped the change in RA

coordinates

would
not match up to the durations of the PulseGuide commands

(but they do match up). Is it possible there

was a

guide star
fade and the autoguider program was mistaking a hot pixel

for a star?

Can you tell me what ASCOM command is to stop tracking

for the GTOCP3? I was thinking of trying to

located

that in the serial I/O stream of the Keyspan utility.

You would see this command ":RT9#", without the double

quotes.

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver:

http://www.gralak.com/apdriver

Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

-----Original Message-----
From: ap-gto@...

<mailto:ap-gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> <mailto:ap-

gto%40yahoogroups.com> [mailto:ap-gto@...

<mailto:ap-gto%40yahoogroups.com>

<mailto:ap-gto%40yahoogroups.com>

<mailto:ap-gto%40yahoogroups.com> ] On Behalf Of

photonphisher

Sent: Tuesday, April 24, 2012 5:24 AM
To: ap-gto@...

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Subject: [ap-gto] Re: Need help with issue in RA guiding

and Synchronous Pulseguide

Hi Ray,
Since I was auto-guiding, the star was brought back

after the fast initial movement. So this 410ms is

probably

that.
Last time I checked the spur gear, it was tight but will

check again.

The weird thing is that this issue occurs randomly (e.g.

sometimes occurs every period, other times

does

not

occur for 4hrs) and more when TheSky6 is connected.
I would imagine with gear looseness, it would be less

random.

Can you tell me what ASCOM command is to stop tracking

for the GTOCP3? I was thinking of trying to

located

that in the serial I/O stream of the Keyspan utility.

Parijat

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gto%40yahoogroups.com> <mailto:ap-gto%40yahoogroups.com> ,

"Ray Gralak" <groups1@> wrote:

Hi Parijat,

I looked at your log file and I do not see anywhere

that the mount was stopping. However, I do see a

*big*

move

sent

from the autoguider program (410 mSecs). Have you

checked for a loose spur gear in the motor box?

BIG move here (410 msecs West move)
019233 2012-04-22 20:32:58.609: ASCOM: Info :

PulseGuide(3, 410)

-Ray Gralak
Author of Astro-Physics Command Center (APCC)
Author of PEMPro: http://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver:

http://www.gralak.com/apdriver

Author of PulseGuide: http://www.pulseguide.com
Author of Sigma: http://www.gralak.com/sigma

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<mailto:ap-gto%40yahoogroups.com> ] On Behalf Of

photonphisher

Sent: Monday, April 23, 2012 7:01 PM
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Subject: [ap-gto] Re: Need help with issue in RA

guiding and Synchronous Pulseguide

Here is the fixed link to the ASCOM log file:

http://tech.groups.yahoo.com/group/ap-gto/files/photonphisher/

Parijat

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, "photonphisher" <parijat_singh@>

wrote:

Hi Ray, Howard,

The RA spike issue has come back again.

I have posted the ASCOM driver log here. The exact

minute of time that it happened was 20:33

and

20:36.

http://tinyurl.com/78wpc42

Here is a snapshot of the guider log. The spike

happens only in RA during guiding.

http://groups.yahoo.com/group/ap-gto/photos/album/104285095/pic/60849235\;
3/view

I have no idea what is going on.

Thanks for your help

Parijat



--- In ap-gto@...

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gto%40yahoogroups.com> , "photonphisher"

<parijat_singh@>

wrote:

I have been facing some strange guiding issues

since some months and deferred posting here

until I

could do

some experiments and narrow it down somewhat.

The issue happens only during guiding (not

tracking) and it is this - A sharp spike in RA guiding

graph of

+/- 5-

10 arcsec occurs periodic with the worm. Upon close

observation, the symptom looks like tracking

got

turned

off

for a fraction of second and the guider brings the

star back.

Here is what I know:

It only happens in RA. Does not matter if PEC on

or off.

It only happens when guiding (I have tried

Maxim, PHD) using ASCOM and not when using ST4.

It starts happening randomly and stops randomly

for certain number of worm periods.

It seems to occur more frequently if I have Sky6

connected to the mount while autoguiding.

Crucially, if I turn on "Sync Pulse-guide" from

the Driver, and disconnect TheSky6 from the

mount,

then

it

does not happen. If I don't turn on sync pulseguide

(driver default) and disconnect TheSky6, the

issues

happens

but less frequently.

Without change to my hardware/software (other

than AP drivers), this issue never occurred until

perhaps

after

I updated to the driver a couple of releases ago (I

am not sure which one).

So, I have ruled out mount mechanics, OTA

mechanics (flexure), PEC, guider

settings/calibration,

hot

pixels.

Given the issue sensitivity to "sync pulseguide", I

believe the issue is something to do with

traffic/collision

on

the

serial port to the mount and driver communication. I

have not changed anything in TheSky6 or other

applications.

I tested the serial adapter/connectivity using

Keyspan utility and and see no issues there.

Has anyone experienced this? Any clues to what

could be going on?

I wanted to try reverting back to an old AP V2

driver; is there a link for that? I am afraid the

"Sync

Pulseguide"

may not be optimal for low latency corrections to

the mount.

Equipment: AP1200 GTO, C11 EdgeHD @f/10, Atik

314L+ imager and DSI I pro mono guider.

Thanks
Parijat