No motion occurs with application built for Labview Runtime.

[ktm1]

I created and built an application in LabView 8.0, and now I am trying to use it on a second computer that does not have LabView installed.  I installed the Labview 8.0 Runtime Engine.  My application starts, and everything seems to be working (buttons, pulling up subvi's, etc.), except that the application doesn't seem to be controlling the motors (there is no motion when there should be). 

I tried building another application from a more simple vi to test the motion control capabilities of the first computer.  When I ran it on the first computer it worked, but on the second computer, again, no motion occurred.

The motors / limit switches / encoders work when controlled through Measurement and Automation Explorer.

Can you tell me why the application isn't working?


Some thoughts:

1.  The motion vi's are under the Dependencies list on the Project created for this application, but I did not specifically select them in the build options.  The original computer runs these executables, but the new computer doesn't have NI-Motion (since it doesn't have LabView).  Does this have something to do with the problem?

2.  The first computer has an NI-7344 Motion Controller.  The second has an NI-7340 Motion controller.  I can't find any documentation explaining the difference(s) between the two.   Is this causing a problem?

3.   In the process of debugging this problem, I discovered another issue.  I think this is a separate problem, but I'll add it here for the sake of completeness.  The motors were recently acquired, and I wired them myself.  I checked the wiring with Measurement and Automation Explorer on the second computer system (the one with the 7340 control card).  Everything worked fine there.  When I attached the hardware to the first computer (the one with the 7344 control card) and ran the motors with Measurement and Automation Explorer, I realized that the motors run in the opposite of the commanded direction.  I will be creating another post for this issue.


Thanks,
Kate

[ktm1]

Nevermind, I figured out the problem.  The Board IDs on the two computers were different.  It was a simple fix.

I'm still confused about what I explained in thought #3, though...

[Allison_S]

Kate,

    I think I can clarify some of your questions.  As far as your first questions, I'm assuming that after changing the board ID's this is no longer a question?  In your second question, all of our Motion boards can be referred to by two names.  For instance, the NI-7340 is the same as the NI-7342, 7344, or 7348.  All are of the same series, but the last digit tells how many axes they can control.  If your NI-7340 has access to 4 axes then it is the same board.  It is possible that it is a different rev of the board and the default display is different.

    Your third question is a fairly common one.  Motors control is usually two lines.  One way is for the lines to be "step" and "direction".  If this is the case with your motor you can change the polarity of the "direction" in MAX and it will move the motor in the opposite direction.  Another possible configuration for the lines is to have "clockwise" and "counter-clockwise" - for each pulse sent on each line, the motor will move one step in that direction.  If the two wires are swapped, then it will make the motor turn in the opposite direction than what is expected.  One last thing, if you have an encoder hooked up and are controlling it as a closed loop, that can also affect the direction.  The encoder sends two signals, square waves, which are offset.  If they are wired one way they will report back to MAX that the motor is moving one direction and if the motor is supposed to be moving the opposite direction MAX will change the direction.  If the wires are switched the encoder will report the opposite movement, which, if it is what is expected, will not affect the motor movement.  I would try one of these methods.

    Let me know if you have any more questions on this, or if you would like further clarification.  Thank you!

[ktm1]

Allison,

Thank you for that detailed explanation.  How can I change the polarity of the motor "direction" in MAX?  I can't find it.

Thanks!
Kate

[Allison_S]

Hi Kate,

    No problem, in MAX, open Devices and Interfaces >> NI Motion Devices >> PCI-734x Default 7340 settings.  Within that folder will be all of your axes.  On the axis that your stepper motor is connected to, click on axis configuration to view it.  Make sure that stepper is chosen as the Type (you may need to press Save at the top for it to take effect).  Once it's set to stepper, another tab will appear at the bottom called Stepper Settings.  Within that tab you have the option of setting whether your motor is step and direction or CW/CCW as well as setting the Stepper polarity, which changes the way the lines are read, which changes the direction.  Let me know if you have further questions 🙂