Unable to run Motion Assistant examples

[edbd1]

I’ve loaded Motion Assistant v1.3 for Windows 2000/XP, which automatically upgraded NI-Motion to v7.0.   I’m using the 7358 card.

When I double click on "C:\Program Files\National Instruments\Motion Assistant\Examples\2 Dimension\2D PVT move.nma," I got

“The motion controller device saved in the script is not present.” and a popup message “File I/O Error while reading from the file …2D PVT move.nma.”  What’s wrong?  Why can't I load the example script?

[Jochen]

You may have to adjust two things:

1. The board number. Please make sure that the board number in the script corresponds to your board number that can be checked in MAX. Please go to MAX anyway and make sure that your motion control board is working correctly.
2. In the example you mention there is a Contoured Move step. Please go to the Contouring Parameters tab of this step and adjust the path in the File Name field if necessary.

I hope that helps,

Jochen Klier
National Instruments Germany

Message Edited by Jochen on 07-21-2005 09:02 AM

[edbd1]

Hi Jochen,

Thank you for your prompt response.  No script is loaded into Motion Assistant after the error messages were displayed.  However, I can move the machine in contouring motion using MAX in its interactive mode.  Also, I can add a contour step in Motion Assistant, select the example .txt data file on the Contouring Parameter tab, and run it.  So maybe the example scripts will not show me much more.  Here's what mystifies me:  I'm trying to use contour motion to move at 1 speed through some XY points and then at a faster speed through some more XY points.  In my input .txt data file, I set the X, Y, V column values, but have not been able to set the T column values so that the motion is smooth while traversing over all the points.  What should the relationship of Time be to X, Y, and Velocity? 

[Rodj]

The script files have an associated board type they were created with.  The many of the example scripts were created with NI-7344 boards.  So when you open the script the program is looking for a NI-7344 board in the system.  One way to work around this is to add a virtual-7344.  In MAX right click on "Devices and Interfaces" and click the Create New... menu item.  From there just follow the wizard to create the virtual board.

Once you open the script with the virtual-7344, you can change the board used by the script to your NI-7358 board.

Rodger S.

[Jochen]

To answer the second part of the question. In contouring mode the board takes one position point (or pair) after another from the buffer with a fixed rate of 20 ms or 10 ms (selectable). Thus the velocity information is implicitely contained in the position points.
Motion Assistant works a bit different. You can pass unevenly spaced position data to the contouring step and MA applies the move constraints (acceleration, velocity) to these data points. This technique is called Smart Contouring. Internally again it calculates an array of position points that fit into the 10 or 20 ms raster.

For more detailed information please refer to the NI-Motion user manual.

Jochen