Straight-line Move controlled through a loop.

[EmHill]

Hey all,

I am having an issue with sending a straight-line move controlled through a loop to geared axes.

I can run the program and send an initial move to the Master axes and both axes move, but when I input a different value for the position neither axes will move.

I have run the program while highlighting the paths on the block diagram and including line values and the execution works properly through each function block, but it does not read the steppers and encoders position as have changed.

I'm assuming it is something I am doing incorrectly, but I'm not sure what exactly..

[protocoled]

EmHill,

Can you tell me a little bit about your set up and what hardware and software you are using? If you are using NI SoftMotion, I would highly recommend first checking out our example of multi-axis gearing using express VI's

In LabVIEW: help > Find Examples > Hardware Input and Output > Motion Control > Soft Motion > Express VI's > Multi axis > Multi Axis Gearing.lvproj. If you are using NI 73xx, we also have examples of gearing. 

Posting a screenshot of your code might also help us easily see what might be wrong!

[EmHill]

Hey,

I am using NI SoftMotion. I looked over that example and tweaked it to reset position as well as just setting up one master-slave combo. When I run the program using the simulated axes, it works exactly as I want it to. When I drag it into the cRIO 9066 device section in the project and use the hardware, the program won't do anything when commands are given to move.

I am using a Parker Zeta12 and Zeta8 driver as well as a Dynapar Series HR26 single-ended encoder. It is an open-loop system.

I'm assuming it is a timing issue or I am incorrectly setting up the axes.

I have written a previous program that moved both the master and slave axes, but would not initiate a second move when commanded.

I will post pictures of both programs here in a bit so hopefully you or someone else can provide specific feedback.

Thank you!

[EmHill]

Attached are screenshots of the original that moves the axes, but will not execute a second move - Labeled as Original.

The second set of three are the changes made to the Multi-Axis example provided by LabVIEW - Labeled as Axis Trial.

[protocoled]

Em,

Thank you for the detailed information. I wasn't able to really get an idea of what's going just based on the screenshots alone. Have you managed to get any I/O working with this hardware configuration before? If not, I think we should take a step back and try to get a simple straight-line move working on a single Axis before attempting to gear multiple axis.

Since you are using a third party stepper drive, my assumption is you are using our NI-9512? If so, first ensure all your connections to your drive are correct as outlined in our 951x User Manual, section 2-2: http://www.ni.com/pdf/manuals/372153e.pdf

From here, if a simple move still isn't working I would ensure your axis configuration is correct. Please refer to the getting started guide, page 13 for help with this: http://www.ni.com/pdf/manuals/372874d.pdf

[EmHill]

protocoled,

I have gotten previous versions of the program to generate a move on the hardware.

But I finally figured out my problem - timing. The code was executing too quickly to effectively communicate with the stepper and encoder. I added some different timing and it started working perfectly. 

Only problem I have now is that the encoder and stepper think -7166.63 steps is 0. So I'm working on that.

Thank you for all of your help!