DAQmx custom scale

[Akiel]

A quick background, we are using create custome scale to convert bar to volts for the AO channel on a 6723 card. Which is working fine, we are able to set m and c values that convert nicely. An added 'feature' we are using is to be able to compensate for inaccuracies in the system (tolerences on transducers,wire resistences etc...) and hence claibrate the system by using a accurate sources/DVMS and again this is working well apart from one channel.

Due to the way the tolerences have worked out and the ranges are slightly different. i have 0-10bar and 0-10v, which in a perfect world would mean m=1 and c=0. using these values gives us ok (ish) readings. To bring the readings in I need m to be nearer 0.98 and the FSD to still be 10. If I set m to this value the FSD becomes 9.8. The post scaled min and max is calculated from m and c by using the pre scaled range.

this is giving a problem that once m<1 the daqmx scale becomes invalid and hence the channel is effectivly disabled. Any suggestions would be much appreciated

Sorry if the explaination is a bit vague ive only just got it straight in my head what is happening

Thanks in advance for any suggestions

[Clad19]

Hello Akiel,

I have been looking at your problem and just want to clarify a couple of points.

From what you have said, I think you are using the DAQmx Create Scale VI in LabVIEW.

I believe you are using the linear scaling option. Is that right?

When you say it becomes invalid and hence the channel disabled, do you get a specific error message pop up? It seems strange to me that you are not able to use a value of m < 1 as an input to the function.

Thanks

[Clad19]

Hi Akiel,

I just wanted to check if you had managed to sort out your problem?

If so, would you be able to post your solution so that the community can benefit.

I hope your application is going well!

Regards,