Motion Control and Motor Drives

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Spline Engine returns zero with all possible inputs

Hello,

 

The Spline Engine in my FPGA code for my controller appears to not be working under any inputs. I have set both reset position and spline data updated to TRUE and made the spline data output equivalent to the highest possible number. The documentation for the spline engine says that with reset position set to zero then the output is set to coefficient 0. This doesn't occur either. I think it is caused by the fact that output valid is always FALSE even though my inputs should provoke a response. Attached is the related segments of my front panel and block diagram.

 

Running on a cRIO 9022.

 

Any help would be appreciated,

 

rustawilliams

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I'm sorry to state the obvious, but, I see in the diagram that "reset position" appears to be set... which would hold the value to the reset value I expect?

 

Edwin!

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If you look at the documentation for the spline engine, http://zone.ni.com/reference/en-XX/help/371093G-01/nismlvhlp/spline_engine/ , reset position TRUE is supposed to set setpoint to coefficient 0 which is not happening. When reset position is FALSE the output valid Boolean indicator is still FALSE and setpoint is still 0.
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Ahah, okay.  Unfortunately, that's the best guess I have, since this is a deprecated version of the spline engine and the version in my computers is from its replacement in SoftMotion.

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What's its replacement?
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There's a spline interpolation VI that has an entirely different API.  "Calculates interpolated setpoints using linear interpolation or a cubic B spline or Catmull-Rom spline algorithm."

 

The old Spline Engine help page just references forward to SoftMotion. I'm not sure when it changed.

 

Edwin!

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