problems with calibation in MAX 4.5 talking to LabView 8.6.1

[cottonpoo]

Hi
I am using using Max 4.5 with a NI USB-6259. When I calibrate a load cell with it, it checks out fine with verify calibration.
When I run LabView 8.6.1 off. the larger the load the more its off. but this happens in tension only, compression is fine.

[aNIta B · Accepted solution]

Hi Cotton,

       I'm curious, is there another load cell that you can try?  How are you saving your MAX configuration?  Are you calibrating for tension as well as compression?  Have you tried using a test panel in MAX to see if its just your LabVIEW program giving you bad readings?  Additionally, is this program that you're running an example program, or one that you've written? Thanks in advance for those answers!

[cottonpoo]

I am calibating in tension and compression, I am having this problem with a 5K load cell. I am also using a 15K load cell without any problems (different channel).

I also am measuring DC voltage (from a meter), DC current (from a meter) and a LRD (linear potentiometer).

I have moved to different channels with the problem moving also.

This is a written program that has been running for over a year on a different test stand.

I have just had a different test stand all of a sudden change its calibration contants for a LRD on its own.

I has taking me 4 hours to get it back.

I have had this happen on another stand @ a year ago. it runs LabView 8.2.0

But I have not had this happen with my test stands running LabView 6.1 or 7.1.1

[aNIta B]

Hi Cotton,

        So then, from what you've said- it sounds like an issue specific to your LRD (since the problem continues when you move to different channels).  It's odd to me that this hasn't been a problem with your test stands in LabVIEW 6.1 or 7.1.1- do you still have a setup where you can confirm that the current problems you are seeing are occuring as a result of LabVIEW 8.6.1?  How are you inputing your calibration constants?  I'm curious how they are changing, and if that could be caused programmatically.  Have a good one!

[cottonpoo]

Thank you for your response.

Since you have confirmed this is a problem with LabView Version 8.* I will be reverting this back to 7.1.1 and Max 3.1

I hope NI is able to get this fixed in Version 9

[aNIta B]

Hi Cotton,

       I have not confirmed that this is a problem with LabVIEW 8.x, but I would like to get some more information from you in case it is.  This way, we can make sure it is documented to be fixed in a later version.  Could you please let me know the answers to the questions in my last post?  Thanks!