9516

[kyleshook]

Hello,

I am currently trying to control a Newport linear stage using a cRIO, Maxon Servo Controller and a NI Servo Drive Interface module. My setup is as follows:

• LabVIEW 2011 SP1
• NI SoftMotion Module Premium 2011 SP1 f1
• cRIO 9074
• NI 9516 Servo Drive Interface
• Maxon 4-Q-DC Servo Control LSC 30/2
• Newport Linear Stage: UTM150CC1HL (Motor: UE404CC)

After looking through the manuals, I have wired the linear stage, servo controller and 9516 module as follows:

(Wiring diagram .doc attached as well)

Note: The only difference between the wiring diagram and what I have setup is that I have disconnected the 9516 "Drive Enable" from the Maxon "Dis in". This is fine with the Maxon LSC because if "Dis IN" is not connected or at ground potential the power stage is enabled.

Before wiring this current setup I used the Maxon LSC and the Newport UTM stage with an external power supply and controlled the stage with the Maxon's internal potentiometer. This was successful.

Now I am attempting to control the stage with NI SoftMotion and am following the "Getting Started with NI 951x C Series Modules and LabVIEW" manual. I have followed the manual and setup an axis and coordinate space in Project Explorer and then tried to test the stage with the Interactive Test Panel. After this step is where I encounter problems. I can get the stage to move when changing the Target Position but, no matter what value I enter into Target Position, the stage will only move a small amount. If I put a positive value it will move one way, a negative value it will move the opposite direction. No matter if I put 10,000 rev or 100 rev the stage moves the same amount. 

I believe the encoder is working because when I move the stage manually the Current Position value on the Interactive Test Panel changes accordingly.

I am a novice to this type of control so am unsure how to ensure that my setup is working properly. I do not believe it is since the stage only moves in small increments. Any help on what I should check/adjust to get my system working properly is much appreciated.

Thank you,

Kyle

(Manuals for the Maxon Servo Controller and Newport linear stage are attached)

[Emily-C]

Hi kyleshook,

Could you provide some more details on the configuration of your axis?

What settings do you have in the Encoder setting? How many counts per unit does your encoder have, and in what units? What settings are you using for the Index Reference Criteria and Active State?

You said that when you move the stage manually the Current Position on the Interactive Test Panel changes accordingly. What units is this change in? Does it match with the settings for your motor? For example, if you turn it one revolution do you see the expected change.

You said that nomatter what position you put in it only turns a small amount. Could you clarify how small an amount this is? For example, does it do one full rotatior, or does it barely twitch before stopping?

Any information you can give me on the configuration of this axis, and what you're setting in the Interactive Test Panels, would help in troubleshooting this issue. Please feel free to post screen shots as well if you think they would be helpful.

Thanks!

[kyleshook]

Hi Emily, thanks for your reply-

The encoder settings are as follows:

From the UTM manual I have gathered the position measuring is "performed with a 2000 pts/rev. encoder, integral with the motor shaft and a 2mm pitch backlash compensated leadscrew." (pg. 2-3 of UTM manual)

I do not know what to put for the "Encoder Velocity" setting. I read through the Help menu about what it is used for but do not know the maximum rpm of the motor.

I am also unsure what to put for the "Active State" and "Index Reference Criteria" in the encoder settings. The UTM manual (pg. 9) provides the following information on the position feedback:

After setting the Encoder Display Units to revolutions and 2000 counts/rev, when I manually turn the stage one revolution the Interactive Test Panel correctly displays that one revolution has occured.

With this set, I tested how many revolutions the stage performs when I change the Target Position on the Interactive Test Panel. All the Move Constraints were left at their default value of 10,000.

• Target position of 10 revolutions: average change of Current Position of 0.586 revolutions
• Target position of 1000 revolutions: average change of Current Position of 0.516 revolutions
• Target position of 10,000 revolutions: average change of Current Position of 0.464 revolutions

So it seems the 9516 Module is sending varying signals to the UTM stage depending on what Target Position input I give it.

I'm not sure where to go from here. Thanks for your help.

Kyle

[kyleshook]

Also -

As you can see from the second image I uploaded in my reply (information about the UTM stage), the "End-of-Run" and "Mechanical Zero" limits are supposed to be TTL type receivers. In the Axis Configuration panel under "Limits & Home" I only have two options for the Forward Limit, Reverse Limit and Home Switch: Input Type Sinking or Input Type Sourcing. TTL input is not an option. This seems like an issue. When I go to the "Limits & Home" Help page, however, I see that the Forward and Reverse Limit and Home Switch are supposed to have input type options of TTL/CMOS - this option is not available to me on the Axis Configuration though. Is there a workaround for this? Please see images:

Axis Configuration Forward Limit

Forward Limit Help

Thanks,

Kyle

[Emily-C]

Hi Kyle,

Have you gone through the Getting Started Guide for the 9516? Some of your settings don't match the suggested settings for getting your system set up. This document is always the first step in troubleshooting. Please make sure that you follow all of the steps, and let me know if you have any questions regarding a particular step:

http://www.ni.com/pdf/manuals/375516c.pdf

Pages 15 and 16 of the NI 9516 Operating Instructions and Specifications shows that the 9516 only allows sinking or sourcing output devices. This also shows the correct circuitry:

http://www.ni.com/pdf/manuals/374990e.pdf

I hope this helps! Please let me know if you have any difficulty with the steps in the Getting Started Guide.

Thanks,

[kyleshook]

Emily,

I have looked through the "Getting Started with NI 9514/16 C Series..." manual but, in my application, I am not using an AKD Servo Drive. The suggested settings seem to reference when using that specific drive. My setup is displayed in the first image of my first post where I have a 9516 connected to a Newport stage and Maxon Servo Control.

One thing I have changed is I am able to get the stage to move the entire length of the track (150mm) by changing the Position Error Limit under the Position Loop window. If I change the value to something very high the stage will continue to move until it reaches it's limit. What is not happening is my ability to control the number of revolutions the stage moves. No matter the number I enter into the Target Position of the Interactive Test Panel (with a high Position Error Limit) the stage just continues moving until it reaches the end of the track.

[Highland_Controls · Accepted solution]

Typically when you have no position control and the axis continues to run, then there is a command reversal.  This usually results in a full torque runaway.  I would lower the position limit back to where is was, and swap the A and A/ not wires.  Try running it again and see if you have control.  Be sure that you have a way to stop the axis(E-stop) in case this new wiring results in a true runaway.

[kyleshook]

Switching the A and A/ wires fixed the problem - thanks!

[example_scrub]

FYI: I want to make sure that I share the latest revision of the 9514/16 getting started document. "Getting Started with NI 9514/16 C Series Modules and AKD Servo Drives"