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Re: servoII controller

Nigel
 
Edited

Hi Dan,
I have altered the check boxes and the mount moves the correct way in Servo Config. But when I use the hand control buttons in SiTech .95P up and down are reversed again.
Nigel


Re: what you can and can't do with SiTechExe under Linux

Don W
 

Hi Mark,

The proper setting of the PIDs is not precise.  Settings work over a wide range of settings.  But you want tthe settings to give you smooth motion of the servos.  What you want to check when adjusting the PIDs is for the servos to operate smoothly and quietly (no vibration or jerkyness) from barely moving to full speed.  So run the servos at tracking speed and also at slewing speed, touch the servo to feel vibration and listen to sound for smooth operation.  You may make changes to settings and not see or feel a difference - that's OK.

Don W


Re: what you can and can't do with SiTechExe under Linux

Mark Copper
 

Progress, I think.

Running ServoConfig on a MS Windows box, I cut the PID integral in half to 1250 and doubled the PID derivative to 8000.

I wasn't able to run SiTechExe095jLinux_ on the MS Windows box, so I switched back to the Linux box and fired up SiTechExe. There the handpad worked in both azimuth directions (cool!). Next I was able to load 2 cal stars and tracking error as reported in the SiTechExe numbers tab remained negligible. No oscillation!

This was all in daylight and further testing is needed (I will be away from the scope for several weeks and would like to post this before I go). But I am grateful to Dan for this suggestion.

I would like to learn more about the PID control -- I guess that's what differentiates servo from stepper. I also wonder if I should try to tune the motors more precisely following the procedure in the ServoConfig manual.


Re: what you can and can't do with SiTechExe under Linux

Mark Copper
 

I have made a little progress on this.

GNU C contains a structure for low-level terminal communication that works just fine with the SiTech Servo Controller I (as you might expect).

With this, it is possible to write C snippets that execute the commands in the SiTech Serial Protocol directly from the Linux computer connected to the controller. In particular, I have a program that runs the "XXR" command, and the controller responds nice and smoothly. (I kept the speed down so no hardhat was needed!) So with a coded formula that computes motor counts for (alt,az) as a function of (time,RA,Dec), one can write a primitive piecewise tracking program as well.

It really gives me an appreciation for the work that must have gone into SiTechExe.exe!

I'm not sure I understand Dan's suggestion about tuning the motors, but I should emphasize that the controller itself performs flawlessly with Nexus DSC and under MS Windows with Voyager so far as I know.


Re: DSCT-1 questions

Dan Gray
 

the TTL has the advantage that it pulls the signal high instead of letting it float.  It will probably work with either because we have pullups on the controller.
Dan


On Mon, Aug 9, 2021 at 1:41 PM Don W <westergren@...> wrote:
Hi v,

You don't specify TTL or open collector, all the encoders that use A-B type square wave output work with SiTech.

Don W


Re: "pulse" tracking in SiTechExe

Dan Gray
 

Mark, what encoder mode(s) are you using?  There's not enough resolution for cascade mode, but tick management would be a good choice.

I'm pretty sure it's not a linux version issue.  The linux version will run under windows too, so you could test it using the same configuration with a windows machine to see if it does the same thing.
95J is a fairly recent version, 95U fixes some comet/asteroid/satellite download issues.
I'll compile a 95U for linux and post it a bit later today.

Dan



On Tue, Aug 10, 2021 at 9:48 AM Mark Copper <mlcopper@...> wrote:
Hi Don,

You have been very kind, and I appreciate it.

Besides, I think you have already helped to isolate the problem. A bug that is unique to the Linux version will be much easier to fix -- for anyone with access to the source code and knowledge of C#, that is. Perhaps Dan could be induced to take a look when his schedule clears a little.

Mark


Re: what you can and can't do with SiTechExe under Linux

Dan Gray
 

Mark, sounds like the servo motors need to be tuned.  There is no difference in linux than windows as far as I know.
Increase derivative, reduce integral.
What is the SiTechExe version you're running?  It should say on skyview or if you make the sitech window wider.
If it's too old, I could recompile you a later version
Dan



On Tue, Aug 10, 2021 at 2:56 PM Mark Copper <mlcopper@...> wrote:

[Edited Message Follows]

Begging your forgiveness for starting a new thread. But with the increasing popularity of single board computers to control telescopes, I'm hoping this may be useful.

SiTechExe.exe will run under Mono on Linux. In my case this version worked with the port set properly: http://siderealtechnology.com/SiTechExe095jLinux_.zip

However, this version has some problems: The principal problem is that once tracking has been initialized using the "goto" button in SiTechExe or using the handpad will send the Az motor into fibrillation, and the virtual handpad rotates in only one azimuth direction. This, of course, renders the scope well nigh useless. And if you have any sense, you will surely go grab a cheap MS Windows laptop.

OK, suppose you persist. Then you can do the following (and perhaps more).
   1. Turn the controller on and start SiTechExe.exe on your Linux computer: $ mono sitechexe.exe
   2. Use the handpad to point your scope at a named star, and put the handpad gently away.
   3. Enter this star in the gotoSync tab of SiTechExe and press the "sync" button and OK in the sync screen. You should be tracking the star now.
   4. Now the challenge: Suppose you want to point the scope towards RA, Dec coordinates (x,y) without restarting. You can do this first by transforming into Alt, Az coordinates for the given sidereal time, then scale to ticks for your scope and execute an XXR command in the terminal window (in the "Controller Stuff" window in the "Features" tab of SiTechExe.

Speaking of the terminal window, if you happen to fall into fibrillation mode, you can reboot the controller with the XQ command without having to power cycle the controller and restart SiTechExe. Terminal commands are documented in the operations manual.
--------------------------------------
A little bit of a setback here.

I did write a simple C++ program to compute Alt/Az coordinates for given RA/Dec, location and time. That's reinventing the wheel somewhat but I couldn't find exactly what I wanted elsewhere even though Dan references (but does not use) an INDI routine for finding the Julian date. I used a formula for finding the Julian date, but, really, it should just be a look-up table.

But that seems to be as far as I can get right now because the terminal window in SiTechExe does not provide the direct connection to the controller I expected.

For example, the ASCI + binary command "XXS" does not get any response from the controller as it should.

It is possible to activate the servo motors with the "X" and "Y" terminal commands, but *only* if the target tick number is followed by an "S" (speed) qualifier. And *only* if SiTechExe has not been initialized. Which is to say I am back where I started: After one star has been initialized, it is not possible to move the telescope without falling into fibrillation mode.

I guess it's all a bit quixotic, eh?


Re: Stars drift with high resolution encoders

Dan Gray
 

Joerg, can you let us know the encoder part number?  The magnetic encoders have a lot of interpolation error.  We should look this up.
My guess, that's the problem.
Dan


On Wed, Aug 11, 2021 at 7:44 AM <Joerg> <joeps@...> wrote:

Hi Russell,

I'm unsure whether I tested Tick Management. Maybe not but as soon as possible I will do that.
But who knows what happens if "Track Only Sidereal (No PXP)" has been clicked?

The text box say: “This option will disable Offset Tracking Rates, and Pulse Guide ASCOM methods.”

Are scope encoders offline at that mode? Do sidereal rate comes only from motor encoder in that case?

 

Joerg


Re: Mount not initialized

Dan Gray
 

Hi Roger, most folks on this group use SiTechExe.  Not too many of us are that familiar with Planewave STI.
But my guess is you simply need to initialize on a star, do a platesolve, or something.  Unless you have absolute encoders, or home switches, you'll need to do this.  Also, you can get it initialized, and then set up a park position, this will initialize on the "Unpark" command.

You can try SiTechExe, it's a bit clunkier, but it's been developed over a period of 15 years, and has most any feature you need.  The latest installer is here:


Dan


On Thu, Aug 19, 2021 at 8:33 AM <yoro@...> wrote:
Hello to all,

Being a newcomer to this group, just hope you will forgive these first steps towards reaching optimal parameters for my new Planewave 200hr mount using the SiTech controler. I also have further questions pertaining to optimal settings, but first things first!
Purchased a hand pad (was missing, but that's another story!) from SiTech, and proceeded forward.
After downloading and installing SiTech and related Planewave stuff , I launched the controler. The controler went in the INITIALIZING mode, but after 4 or 5 seconds, it came up with a NOT INITIALIZED response. Problem surely lies in front of the screen here! Must have missed something...
PLS disregard CONTROLER INFO/PAN commands, as this printscreen was taken afterwards!
In any case, your take on this will assure that I'm going in the right direction ;-) this being the first of a couple of issues (later!).

Best regards to everyone.
Roger Venne
Frontenac Qc. Canada


Re: servoII controller

Dan Gray
 


Hi Nigel,
Gary is on the right track, but you can't do it with those buttons.  You have to click on "Edit Parameters" and use the check boxes near the bottom of the screen.
If the motor works, but goes the wrong way, simply change both of the checkboxes for the motor.  If they're on, turn them off, and vice versa.
click ok, and save to controller.
Dan


On Sat, Aug 14, 2021 at 4:03 AM Gary Hug <garyhug@...> wrote:
Hi Nigel,

Go To your Servo Configuration (not SiTech.exe) and on the first screen find
where it says Azimuth/RA YBits and just below that find Invert Motor Encoder and
Invert motor and just click on both blue boxes. It should change the direction
of your RA drive.

cheers
Gary

On 8/14/2021 5:40 AM, Nigel wrote:
> Hello, I have just replaced my Servo II Controller. The problem I am having is
> if I press the Left button on the handpad or the onscreen panel the mount slews
> right. I believe the mount is also tracking in the wrong direction.
> Any help would be appreciated.
> Nigel
>






Mount not initialized

yoro@...
 

Hello to all,

Being a newcomer to this group, just hope you will forgive these first steps towards reaching optimal parameters for my new Planewave 200hr mount using the SiTech controler. I also have further questions pertaining to optimal settings, but first things first!
Purchased a hand pad (was missing, but that's another story!) from SiTech, and proceeded forward.
After downloading and installing SiTech and related Planewave stuff , I launched the controler. The controler went in the INITIALIZING mode, but after 4 or 5 seconds, it came up with a NOT INITIALIZED response. Problem surely lies in front of the screen here! Must have missed something...
PLS disregard CONTROLER INFO/PAN commands, as this printscreen was taken afterwards!
In any case, your take on this will assure that I'm going in the right direction ;-) this being the first of a couple of issues (later!).

Best regards to everyone.
Roger Venne
Frontenac Qc. Canada


Updated TLEs for maneuvering LEO satellites

jmgoldba
 

Recent post over at le SkyChart about this. Not sure if it's worth the bother on the SiTech end but interesting for LEO observers. -Jesse


Re: Track past Meridian 95p

pburke@...
 

Hi Don....(and Dan) Thanks for working on this problem with me... What I thought was a polluted model actually turned out to be another culprit.... This was my RGSZ 20 scale tape that was on the Ra axis... for 6 years!
Replaced the scale.. checked both TPR for the encoder and motor... And works great now!
Thanks, Paul


Re: "siteching" a Celestron CI-700?

jervisbayastro
 

Dave,
I went down that same rabbit hole but can't find the end now. Digging back through my CI-700 'database" I have found other CI-700 related info I've collected plus there could be a copy of the original "Hercules" page files and photos. I haven't worked out how to reconstruct it yet but there appear to be some photos which may be of use. I'll have a dig through it.

In my original reply I conflated what I thought I remembered of that site with this one regarding the thrust bearing mod. 
http://www.skydude.me/ci700mods.html

Not sure if this page is relevant.
https://www.cloudynights.com/topic/374428-why-am-i-wrong-synscan-upgrade-on-a-ci-700/page-2

A CI-700 OnStep conversion in french, but the photos don't need translation :)
https://www.webastro.net/forums/topic/168576-onstep-celestron-ci700/

I think the attachment is from the CN archive.



Re: "siteching" a Celestron CI-700?

Dave Lane
 

I take that back - it looks like the actually content pages were not archived. :-(


Re: "siteching" a Celestron CI-700?

Dave Lane
 

Col,

I found the linked website on the internet archive (an excellent site for finding old content back as far as the mid 90s!).

See: https://web.archive.org/web/20041125031511/http://www.geocities.com/jgfusco3/CI-700Hercules.html

--- Dave


Re: servoII controller

Gary Hug
 

Hi Nigel,

Go To your Servo Configuration (not SiTech.exe) and on the first screen find where it says Azimuth/RA YBits and just below that find Invert Motor Encoder and Invert motor and just click on both blue boxes. It should change the direction of your RA drive.

cheers
Gary

On 8/14/2021 5:40 AM, Nigel wrote:
Hello, I have just replaced my Servo II Controller. The problem I am having is if I press the Left button on the handpad or the onscreen panel the mount slews right. I believe the mount is also tracking in the wrong direction.
Any help would be appreciated.
Nigel


servoII controller

Nigel
 

Hello, I have just replaced my Servo II Controller. The problem I am having is if I press the Left button on the handpad or the onscreen panel the mount slews right. I believe the mount is also tracking in the wrong direction.
Any help would be appreciated.
Nigel


Re: "siteching" a Celestron CI-700?

jervisbayastro
 

Hi Dave,

I have a CI-700 waiting for a goto conversion but lack of parts and machining skills has stalled it for now. My research took me to a few sites including Cloudy Nights and Jim Fusco's CI-700 upgrade https://astromart.com/reviews-and-articles/reviews/telescopes/show/ci-700-hercules.  Unfortunately the link to his notes etc no longer seems to be accessible but at some point in the past I was able to see what he. Consequently I acquired the NTA-4860 needle roller bearings he used to replace the existing thrust surfaces to improve the rotation of the RA and Dec. I may have some other references to CI-700 mods if you're interested.

Regards,
Col Shepherd


Re: "siteching" a Celestron CI-700?

Joshua Hufford
 

Well, free is certainly good! 

I would certainly try not to image with the C14 on this mount, I think that would really be pushing it. 

The other poor design of this mount is the clutch system, the tighter you make the clutch the more friction there is to movement of each axis and more load on each motor. From what I understand the clutches are actually designed to slip when you want to move the scope to a new target, then the scope begins to track again when you stop moving. 

Honestly, if the drives still work on the mount, I would probably just use it for visual observing with the stock drive, this mount is not the best candidate for converting to GOTO. 

BTW I believe I have mounting brackets for encoders if you would be interested, the encoders have been repurposed, but I still have the brackets. 

It is neat that you designed the Kendrick Dew controller, I think it is a fantastic unit. I actually have 2 of them, both bought used. One of them has a failure, either the temperature or humidity doesn't sense properly (don't remember which one now). My friend Anthony uses it and just sets the heat percentage manually. The other one I have still works perfectly. I always thought this was a great design, great job! I don't think they are sold any more? 

Josh

On Wed, Aug 11, 2021 at 7:26 AM Dave Lane <dave@...> wrote:
Thanks Joshua, for the detailed reply and pictures. I originally thought it might have been built by Losmandy, but my googling would indicate it was Celestron's first attempt after reselling/rebranding the G11. The mount is free to me - a fellow is giving me a long unused C-700 + C14 from the mid 90s. I expect it really is not beefy enough for a C14, except for visual use. I'm also getting a couple of what looks like un-used Meade Pictor CCD cameras :-).

Dave

ps. I see you have one of the rare Kendrick Premier Power Controllers - that was my design. I never did get one myself. He did not sell many of them based on the royalties that I received!

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