Changing the velocity ratio using a value Motion

[Himanshu]

I want to change the velocity ratio of the two axis being controlled using a Value Motion software and PCI-7324 boards.I can not locate any function in the value motion library which changes the velocity ratio of the two stepper axis. Please help me since I need to change the velocity ratio of the two axis for drawing an ellipse. It would be very good if I could get some other idea of generating an ellipse using stepper motor control card PCI-7324 and value motion software.

[JR_A.]

There really isn't a good way to create an arc or an ellipse with ValueMotion. You could do a series of vector moves as demonstrated in the example VI's, however the motion will come to a complete stop in between points. Or you could try adjusting the velocity of the move however that is going to have to be done in software while it is moving and you probably wouldn't get very good results depending on what your parameters and requirements. The best and easiest solution, which you're probably aware of, would be to get a 7344 which uses the FlexMotion driver. The 7344 has the ablity to do all of this in hardware.

Regard,

JR A.
Application Engineer
National Instruments