motors run in opposite directions for 2 computer / motion controller systems

[ktm1]

I recently acquired wired four motor/slide systems.  Three are NEMA-34 motors and one is a NEMA-23 motor.  I wired them all in the same way as I have done before and then checked my work by running them with Measurement and Automation Explorer (MAX).  The first three worked fine, but the fourth (a different type of motor) went backwards, so I switched some wires to make it go in the right direction.  I assumed that I had made a mistake.  Now all four work correctly with MAX on this computer.

Since then, I have been attempting to transfer some software created in LabView to this system.  As part of the debugging process, I hooked the motor/slide system up to an older computer.  I discovered that the motors run backwards from this computer's MAX.  The limit switches work correctly, but this causes additional issues, because MAX thinks that it is at the negative end of the axis when the positive limit switch is hit, and so the slide doesn't stop when the limit switch is hit.

The major difference between the two computer systems is the motion control card.  The first, newer system has an NI-7340.  The second, older system has an NI-7344.  I can't find any documentation explaining the differences between these two controllers, but I can't imagine a difference that could cause this problem.

This seems like a very strange problem to me.  Can you give me any ideas about what might be going wrong?

Thanks,
Kate

[VuD]

Hi Kate,

It sounds as though there may be an issue in the controller configuration in Measurement & Automation Explorer.  Have you checked the stepper polarity in MAX?  This is in the "Axis Configuration" settings on the "Stepper settings" tab.  I would also suggest double-checking that the other settings are the same on both computers (motion I/O polarities, encoder settings, etc).  To answer your other question, the NI-7344 is actually in the NI-7340 series of motion controllers.  The xxx4 signifies the number of axes on that particular card (there may be some slight revision changes, but no major differences).  I hope this helps. 

Vu