Why don't I get pos. and neg. direction from my stepper motor through Labview?

[mdkluck]

I have a stepper motor that is controlled by the NI Motion Control card, NI PCI-7342. I can get the motor to spin in both the positive and negative directions in the Measurement and Automation Explorer, but not through the Labview code for arc motion. I was wondering if there is a reason why it is unable to rotate in either direction through the code.

[Jochen]

I have just tried the Two-Axis Circle with Position Monitor.vi that is located in the examples directory and it's no problem to draw circles in positive and negative direction with this vi. The only thing you have to do in order to change direction is to change the sign of the Travel Angle value (e. g. -360° or +360°).

I hope this helps,

Best regards,

Jochen Klier
National Instruments Germany

[mdkluck]

Thank you. I actually figured it out shortly after writing the question. I used the Load Target Position function.

[Bill_5335]

I would like to make a change to the Two Axis Circle VI. I would like to change the direction onf the X axis.  If you envision an X Y grid, the circle is "drawn" on the negative side of the Y axis.  I would like to change it so that the circle is "drawn" on the right side of the Y axis.

I think I need to change the direction of the X axis motor, but I can't see where to change it.

Thanks,

Bill

[Jochen]

Bill,

you should play around with the start angle parameter of "Load Circular Arc.flx". E. g. if you are now using 0°, try 180° to inverse the angle the circle starts.

Kind regards,
Jochen