MAX and ValueMotion: execute differently given the same trajectory parameters

[lcp]

I'm trying write a LabVIEW program to move a stepper motor to a specific position at specific velocity and acceleration. The end product needs to be a user-friendly VI that can do all needed steps without the user opening Measurement and Automation Explorer(MAX).
Here's the problem:
The only way that I've been able to get the thing to move at the desired acceleration/ velocity profile is to make the same motion immediatly prior using MAX.
For example, I want it to move at 2000 steps/s and 100 steps/s^2. This is what I have the initilization configuration set to. However if I pass this information directly into my labView program it actually moves differently (slower acc.) then if I run it
directly from MAX (the interactive 1-D part). However if I make it move using MAX and then immediatly run my LAbVIEW VI it operates identically to the MAX execution.

I've tried directly telling the VI the velocity, acc. etc. parameters, that doesn't help. The acceleration factor everywhere is the same (1). I don't understand why 100 steps/ s^2 in my LabVIEW code excutes differently at different times.
Thanks.

[nestor-sg]

I will advise you to try out the examples shipped with LabVIEW to see if this makes a difference. You can find the examples at:
C:\Program Files\National Instruments\LabVIEW 6\examples\Motion\ValueMotion
... specifically look for the library name stepper.llb which has inside an example VI named "Sequence of Moves with Low Level Parameters". Please try this example and check the VI "low level parameters" in the block diagram so you can manipulate the parameters and see if they do take effect on your motion system.

Also make sure that you have the latest driver for Valuemotion which is 5.0.2 (http://www.ni.com/downloads/) and if you still see more issues you may want to contact us directly to troubleshoot the board or software, please find the procedure at www.ni.com/a
sk on the web.

Last, please do check that this settings you mention are actually set in MAX but in the axis trajectory settings, not in 1D interactive, because 1D interactive will reset to its default value whenever MAX is closed, so this is why you may be seeing the same movement only after you run MAX. Please check the example that may give us some idea, and please do it with MAX closed. Thanks!

Regards,

Nestor Sanchez
Motion Control Support
National Instruments