arc.vi 's input "Radius" is distance from arc centre or distance from vector space centre 0,0

[S_Kanchap]

Hi everybody,

I am using PXI 7352 +UMI+2 servo Drives+motors which move a table in linear direction X and rotate it along Z axis C.

How can I use Load Circular Arcvi if my  one axis is linear and other is rotary e.g. XC table.

Thanks

Surender Kumar

Reckers Automation

Delhi

[Jochen]

Surender,

the arc move feature of NI-Motion boards is meant to be used with orthogonal xy-stages. Every other geometry will result in transformed moves. I don't think that there is a good way to use this function with your setup in order to create arc moves.
My suggestion is to use contouring instead. With contouring you can precalculate an array of x-y positions and download them to a buffer on the board. This will give you the flexibility to work with any mechanical axis-setup. Please refer to the contouring examples that ship with LabVIEW.

Best regards,

Jochen Klier
National Instruments Germany

[S_Kanchap]

Thanks,

Your answer is very helpful,

1.   I have already ask NI.India about data length to store in program variables but they told me that I can     store a very little bit of data say 100 values only.

But if I need to machine very precisely say in microns then I have take very nearer values then data length will be too much 1,00,000 values or much.

How can I tackle it.

2. I need to use "tool radius compensation" also, How can I use it using Labview.

3. My achitecture is RT -- Host.

Thanks again

Surender

Reckers Automation

New Delhi---India

[Jochen]

Surender,

1. You can run contours with an (almost) infinite number of position points. The trick is to load new data into the buffer when it has depleted to a certain amount of points. There is an example in LabVIEW (Buffered Contouring (Rose).vi) that shows this method. Maybe there was a bit confusion when you talke with NI India in terms of wording. There are also onboard variables (about 100) but these are not used for contouring. Contouring data is stored in an onboard buffer.
   In contouring mode the board interpolates through the position points stored in the buffer with a rate of 10 ms (minimum). Inbetween these poionts the board interpolates using a cubic spline algorithm. In terms of accuracy this method is equal to the arc move as arc moves use a similar internal mechanism as contouring.
   
   
2. With contouring of course you could take care of the tool radius compensation in your calculations but there is no ready to use solution for that in LabVIEW. Maybe a 3rd party solution is available for that (please refer to this thread which you should know already).

Jochen

[S_Kanchap]

Hi Jochen,

Thanks for your efforts.

I have bought ABM NI NC only due to the same reason e.g. "tool radius compensation" after their confirmation that it will support RT target also but now after purchasing they are saying that it can't support RT.

Because I am working upon Rt, ABM NI NC is no longer useful for me.

Is there any support from where we can got help e.g. NI itself.

Or We can got the concept of the same in mathmatecal form and then we can implement it in Labview.

Thanks,

Surender

[Giridhar_Rajan]

Hi,

I have implemented cutter compensation, both left and right compensation in one VI.

Regards,

Giridhar Rajan

Automation Engineer

Cruiser Controls

Mumbai, India

[S_Kanchap]

Hi Giridhar,

Please send me that vi.

Thanks

Surender

[Giridhar_Rajan]

Hi,

Give me your contact number and e-mail.

Regards,

Giridhar Rajan (Mobile: 09821037848)

Automation Engineer

Cruiser Controls

Mumbai, India

rajan.giridhar@gmail.com

[S_Kanchap]

Hi Mr. Giridhar

You can contact me at 09899106291 and

skanchap@rediffmail.com

pc@reckersreckers.com

Thanks,

Surender

[Giridhar_Rajan]

Hi Jochen,

Please tell me the way to precalculate XC values of any ARC segment. say start point is 100,150 end point is 500,700 with radius 1000.

But these values are XY values.

Thanks,

Surender