Softmotion Axis Configuration Limits Registering Backwards

[ELDMATT]

I am using a Yaskawa EtherCAT Sigma V servopack with LabVIEW and the Softmotion module and have run into an issue with configuring the forward and reverse hardware limits.

The limits are wired properly to the servopack and their operation has been verified.  I would like to be able to monitor whether these limits are activated within LabVIEW, but when enabling the limits in the axis configuration window and testing the software, I find that the forward limit registered by the Yaskawa servopack triggers the reverse limit within LabVIEW.  Likewise, the reverse limit registered by the Yaskawa servopack triggers the forward limit within LabVIEW.  This results in the servopack stopping all motion in one direction and LabVIEW restricting motion in the opposite direction, prohibiting moving off of the tripped limit.

I am new to Softmotion.  Would this be a LabVIEW issue, or is it possibly an error in the Yaskawa ESI file?

I tried working around this by selecting 'Do not stop' as the stop mode, however this function does not appear to work properly, either, and the motor is stopped by the software regardless of travel direction and limit depressed.

Thanks,
Matt

[anson.kunjappy]

Hello,

Could you tell us about your axis configuration settings in regards to your limits. 

Can you post a picture of your code? It would be useful to know what functions you are using.

Anson K

Applications Engineering

National Instruments

[ELDMATT]

Attached are images showing the axis configuration menu used to configure the limit settings.  The screenshot shows the 'enable' and 'stop mode' settings for the forward limit.  The reverse limit is configured in the exact same way.  Additionally, I have attached a screenshot of the code I am running.  The code is 'Axis Straight Line Move.vi' from the NI examples modified slightly to read the state of each physical limit switch and display as indicators on the front panel.

Finally, I have included screenshots of the front panel showing the FWD and REV limit indicators active while also showing in the background the Yaskawa Sigmawin+ interface running showing the servopack indicating the opposite limit is active.   

[Karl-G · Accepted solution]

To answer the initial question, this should not be an issue with LabVIEW or SoftMotion. The problem appears to be with the code that is being used to connect a SoftMotion Unbound Axis to the Yaskawa Sigma V EtherCAT drive. Given the look of the project in your screenshot, I am assuming it is the community provided code in the link below.

https://forums.ni.com/t5/Example-Program-Drafts/NI-SoftMotion-2009-Axis-Interface-and-3rd-Party-Ethe...

The primary difference between that example and all of our official EtherCAT drive support is that this example uses an Unbound Axis. This means that all communication between the EtherCAT drive and SoftMotion is exposed in LabVIEW RT code provided in the forum. Beginning in 2015, NI has offered an official extension for SoftMotion to third-party EtherCAT drives, SoftMotion Drive Interface (SDI). SDI uses plug-ins that interface between SoftMotion and various drives and provides a uniform programming interface that does not require customization. The list of supported drives is below, but only includes the current Yaskawa drive, the Sigma 7.

http://www.ni.com/white-paper/52867/en/

Now to your issue: it looks to be caused by a simple flipped bit assignment from the drive's Digital Input word (0x60FD) and the LabVIEW RT code assigning this to a SoftMotion axis. In the attached files, you can see that bit 0 of the drive's digital input word is the Negative Limit, and the RT code in the AxisInterfaceMulti_eCAT_IO_Var_Data.vi assigns the first bit to the Forward Limit. Swap the top two Boolean inputs to the Latch Limits VI, and I'm guessing the behavior will be correct.

[ELDMATT]

Karl - 

You help is greatly appreciated.  Your assumptions were correct and this was indeed the issue.

I am aware of the available SDI plugins, however the Yaskawa EtherCAT drive available to me is a Sigma V, which is yet to be supported.

Thank you again for the fast, detailed response.

Matt

[MelVID72]

Hi,

I have a SoftMotion problem to and you seem knowing this librairy.

I am currently working on an engine using a Yaskawa Pick and Place. This machine works with a LabView exe and seems to drive properly the Pick and Place. For futher other reasons i would like to debug this program and the supplier send me the similar program. But when i want to drive the 8 axis of the robot The trouble appears. Enclosed to this question the error send by the interactive pannel send me an error -70229 and said that we have a trouble with the driver. We have check and the driver is installed on the target (LabView Real Time controller). Do you have some idea of our trouble ?

Thank you very much for your time, i hope you have some idea.