Latest and Greatest Labview Driver to Control Velmex Vxm Stepper motor

[Sami.B]

Hello,

 Currently, I am using Labview 2009 (version 9.0.1). We are using Labview to control a Velmex VXM stepper motor. The latest and great driver that we're using is:

VxmDriverLV7_1.vi

This seems to be out of date (judging by the 7_1). I checked the NI website as well as the link you sent me, and couldn't find a later version of this driver. The reason I'm inquiring about this driver is because our system sometimes crashes. I think it's due to our RS-232 connection between the PC and the stepper motor, whereby our commands to the stepper motor are sent via this driver VxmDriverLV7_1.vi.

Our RS-232 settings are as follows: 9600 baud, 8 data, no parity, 1 stop bit, Xon/Xoff

This is all I found on the subject so far (a preview thread): http://forums.ni.com/t5/LabVIEW/VXM-Stepping-Motor-Controller-Driver/m-p/1469394#M558207

Any assistance would be greater appreciated. Thank you.

Best,

Sami

[Kimberly_Wenger_Austin]

Hi,

In regards to different versions, LabVIEW 2009 will run a VI from LabVIEW 7.1. For more information about compatibility between different versions of LabVIEW, please reference this document: How to Upgrade or Revert a VI to a Different Version of LabVIEW

Could you provide some more clarification about how the system is crashing? Are you getting an error or does it just freeze? If you get an error, please post a screenshot of the error. When does it crash--at the beginning of the program or after it has been running for a while? Is the system crash intermittent or consistent?

Thanks!

Kim W.

[Sami.B]

Hello,

 We're using Labview version 9.0.1 to control a Velmex Vxm stepper motor in an x-y plane. The latest and great driver that we're using is:

VxmDriverLV7_1.vi


This seems to be out of date (judging by the 7_1). I checked the NI website and couldn't find a later version of this driver. The reason I'm inquiring about this driver is because our system sometimes crashes. I quite certain it's due to our RS-232 connection between the PC and the stepper motor, whereby our commands to the stepper motor are sent via this driver VxmDriverLV7_1.vi.

The crash usually involves the PC's cpu spinning out of control (100% usage), but not always. If we use a USB-to-Serial adapter instead of a real RS-232 serial connection, the system will crash, but not as quickly (usually after 15-20 minutes). The crash is not a "blue-screen-of-death" occurence, rather, it's more of a "system-hang" / " labview or Vxm motor timing out" sort of thing...I feel as if the input buffer into the Vxm stepper motor is waiting for more characters of data, then Labview simply stops responding. It's like the driver VxmDriverLV7_1.vi locks up...We don't get an error, the system just "freezes" or "stops responding". The system will crash, usually, at the beginning of the program (within the first 10 seconds or so). The system crash is consistent.

Our system also uses a DAQ, the High Accuracy M Series USB 6289, as our data acquisition engine. Should I be using the latest and greatest driver (DAQmx 9.2.3) for this M Series DAQ to achieve a more stable system for Labview 2009? 

Computer:
3 GB of Ram, Windows 7, Pentium Dual Core 2.00 GHz

RS 232 Port Settings:
9600 baud, data 8, flow control none, parity none, 1 stop bit

Thank you Kim.



Best,



Sami

[jdubs]

Sami,

I am curious where this driver comes from.  Can you point me towards it so I can take a look?  From what I could find about your device, it looks like you just need to send ASCII characters to the motor.  Have you tried using NI-Serial or NI-VISA VIs to communicate with the device?  If that link is not to the right device, can you point me towards that as well?

To troubleshoot the problem further, you can try taking a spy capture.  However, this assumes that the driver uses NI drivers under the hood.  If this is not the case, then the spy capture won't do much. 

In terms of upgrading the DAQmx driver, you don't have to upgrade as long as the version you are using is supported by LabVIEW 2009.  This information is in the readme for the driver, under Supported Development Environments.  Upgrading in this case may or may not make much of a difference.

Thanks!

Jen W

Applications Engineer

National Instruments

ni.com/support

[Sami.B]

Hi Jen,

 We obtained the driver from Velmex, which can be found here at this link:

http://www.bislide.com/controls/faq/labview/labview_7/ex_examples.htm

We use this driver "VxmDriverLV7_1.vi" to send those ASCII commands to the motor: this driver abstracts all of our stepper motor commands.

Thanks,

Sami

[Sami.B]

Hi Jen,

 I've also attached the Spy Capture log of when we crash. Thanks.

 Best,

Sami

[jdubs]

Sami,

Thanks for the additional information.  From the spy capture, it does not look like there are any VISA errors that are causing the crash.  It would have shown up in red with an error code if one had occured.  Instead, it looks like the log just ends.

From the link, it looks like the driver comes from the vender of your motor.  Have you contacted them to see if they have seen any problems like this in the past?  They might have more access to resources on what the driver does, as it is not something that comes from NI.  I completely understand that the abstraction makes it much easier to program.  However, to eliminate LabVIEW as the cause, a simple program using VISA should be written and tested.  That would take the driver out of the equation.

Regards,

Jen W

Applications Engineer

National Instruments

ni.com/support

[MikeBowen]

We having a similar problem, and are considering writing our own drivers that use VISA to automate writing and reading commands.  The command language is really pretty simple, just reading and writing command strings.  In our case we are using it for manufacturing test.  The original development was done in the United States, and the testing is being done in China.  When doing original development there were intermittent lock ups.  When I rewrote the code the intermittent lock ups in the US went away, and then the fixture in China would lock up.  It just freezes, I suspect the CPU usage is going to be off the chart like in the screen shots.

I did notice when checking on the Velmex web site that there was a page that mentioned a Reset Driver function, and there was a big disclaimer that this function is not available in LabVIEW.  The LabVIEW VI also has a considerable number of terminals.  There is a Char Timeout Time terminal that is suppose to reset the motor if the time value is exceeded, I would probably put that option in the driver.

Mike

[niunc2011]

hi all,

I am suffering the same problem: using labview 2009 and VxmLV8 driver. 

The crash is consistant, around 8 minutes after I restart the program.

Any solutions so far? 

[CRivett]

Did anyone ever write a substitute program for the Velmex driver? I'm using the same thing and it is causing a LOT of grief. If anyone wrote a replacement driver I'd be extremely grateful to see it.

thanks you!