ServoConfig/Ticks Determination Problem


Raphael T Vilardi
 

Dear All
When using the ServoConfig/Ticks Determination tool I'm having the following problem: The angles reading and TPR are double counted, that is, the mount would turn 180º
but the angles reading would show 360° and the TPR would also display the expected figure for a full 360° turn. I didn't pay much attention to it when I used the tool and until  I first started to use the go-to feature with the Sitec last evening. I've found out that, when choosing a given object and hitting go to button, the slew would stop halfway. Has anybody run in this kind of problem?? Best regards to ALL


 


Don W
 

Hi Raphael,

Tics per rev is for 360 degrees.  In ServoConfig.exe, when you use Ticks determination, the RA defaults to 360 degrees.  However, there is a box labeled "Ending Degs" where you can put in 180° or any other setting.

So you have two choices:  either run ServoConfig ticks determination with 180° in that box, or simply go into "Edit Parameters" and put in twice the ticks/rev for RA.  Then you have to save the results to the controller and also to Flash memory.

Don W


Raphael T Vilardi
 

Hi Don

Thanks for the comments. However the situation is the following:  when I check  the box Azimuth and input 360° for instance and hit the second button, two things happen as the mount starts to move: 1) one can clearly see that the angles displayed do not correspond to the physical movement (I had a laser attached to the mount and pointed at a target hanging on the wall as the start and finish point and I could  easily track the red dot movement); for instance you are visually at, roughly 45° and the angles count would show 90° . 2)  the slew would stop at 180°, regardless of 360° number input, as if it would have completed the full circle. And the encoders TPR would also show the figure expected for a full circle. I’m pretty sure of this figure as I know the encoders quadrature ticks, the gearbox exact reduction and the main gear number of teeth (500 X 4 X 50 X 220 = 22,000,000). There is no way this number of TPR could be reached with a 180° turn. The system is actually counting both in double.

And if this data is  transferred to the Servo Controller, it could explain the strange behavior I've noticed yesterday; when hitting the go to button the telescope would slew and stop halfway as if it would have completed twice the angular distance between the starting point and the selected object.. How can I fix this?

Best regards
Raphael


Raphael T Vilardi
 

To be more clear: the scope would have moved 180º but the angles display would show 360º and 22,000,000 TPR


Yann-Eric Boyeau
 

Hi,

 

Does the mount move as it should if you just put manually 44,000,000 TPR in the number of ticks per revolution. ?

 

YE

 

 

De : Sitechservo@groups.io <Sitechservo@groups.io> De la part de Raphael T Vilardi
Envoyé : mercredi 5 mai 2021 09:11
À : Sitechservo@groups.io
Objet : Re: [Sitechservo] ServoConfig/Ticks Determination Problem

 

To be more clear: the scope would have moved 180º but the angles display would show 360º and 22,000,000 TPR


Raphael T Vilardi
 

Hi Yann. Thanks for the suggestion. I'll try it and let you know. But what bugs me is that, the very first time I did the Ticks Determination it was working fine. It did the first full 360° CW cycle and showed the correct TPR. However, when it was doing the CCW, the AC power cord disconnect and I switched to a 12V power pack, that I’ve been using all the time. That's when the odd behavior started. Perhaps I should uninstall the Serco Config App and reinstall it. Unfortunatelly I won't be able to do it before next Friday. I'm loosing some rare clear skyes around here... best regards


Don W
 

Hi Raphael,

When you run the ticks measurement in Servo Config, you put the 360 degrees into the box.  When you are measureing the tics, whatever is in the box is probably wrong, since the data is not yet set into the controller.  Try YE's suggestion.
Don W