Hello, my question involves using the flex motion controls within labview.

[EEburnin]

I am using the Flexmotion libraries to control stepper motors connected to the PC7334 PCI card. I can move the motors when I set the operating mode to Relative position then load a velocity followed by loading a target position all in steps. I then start the motion and the motor steps properly. I then change to velocity control in a different part of the application and run the motor at the loaded velocity. The steps are accumulating properly however when I change back to relative position mode and provide the stepcount to the target position the motor moves to the last loaded relative target position + the number of steps I loaded. It doesn't increment in a relative fashion from where I eneded up after the velocity mode move. Any hints as to what my be going on would be appreciated.

[AnalogKid2DigitalMan]

You may want to post this in the Motion Control Forum

[RManion]

Hi,

Regarding the issue you are experiencing, I believe I have seen similar behavior in the past. If I remember correctly, the problem was resolved by executing a halt after each move type. Make sure this is the case, but let me know if it is still giving you trouble.

Worst case scenario we could reset the position using the current encoder position. Though it is definitely a workaround, at least the move would work correctly.

let me know how it goes, I am very interested.

Robert

[EEburnin]

Thanks for both of your feedback. It turns out that the problem was the Kill command while in velocity mode. I was activating the command once the velocity move was finished. This must have been putting the controller in a strange state. I changed this to the decelerate to 0 stop command, as it should have been anyway, and everything works as I expect.

Thanks