Modified DAQmx scales do not apply until LV app is restarted

[Dr_M]

I have an application that changes several DAQmx scales during online calibration of sensors.  The new scale ranges are correctly written back to MAX but they only apply once the LV application has been closed down and restarted.  Why allow scales to be programmatically modified if you then can't use the modifications immediately - this seems like a bug, an oversight, or there is actually a method to do this - but I can't find it.

Is there any way to programmatically get DAQmx to start using modified scales as soon as they are changed, while the LV app that modified them is still running?

My only alternative is to avoid DAQmx scales all together and create and apply my own from a lookup file.  This adds a lot of extra programmming which is a real nuisance that I am trying to avoid.

[Hillman]

Hi Dr Spock,

Good Morning and I hope your well today.

I have noticed that you have recieved any support for your issue and I can see that you re-visited the forum recently since your post. I am sorry you haven't received any support thus far, so I would like to help. Firstly, are you still having problems?

If so, I will do my best to replicate the issue. I have so far, not found any issues - but I would like to replicate this first.

1. Is it possible for you to send me some example code which reproduces this issue?

2. What version of LabVIEW and DAQmx are you using?

3. I have found two examples - are these similar to your code, do these show the issue?

Change DAQmx scales in LabVIEW and save the changed scales to MAX

http://sine.ni.com/devzone/cda/epd/p/id/1625

NI-DAQmx: Using Multiple Scales with NI-DAQmx

http://sine.ni.com/devzone/cda/epd/p/id/896

4. To understand correctly, the modifications you've made are updated in MAX but when you setup the DAQmx task its using the previous settings? If so, is the DAQmx task running? I imagin the DAQmx must be stopped or even not created before applying a new DAQmx Scale.

I look forward to hear from you soon, and with working with you on this issue if you are still having problems! 

[Dr_M]

Hi James,

It is correct that I am not stopping the task.  I can imagine that will help and I will try that next time.  I have changed the application to get around this problem since the first posting, so I will try your suggestion the next time I do a similar application.  Do you think just a stop and restart of the task will apply the new scales?

Thanks,
Mike

[Hillman]

Hi Mike,

Thanks for the prompt reply and I hope your well today.

I believe you will need to stop, and destory the task. And then create a new DAQmx task using the new scale. This is because the scale input is for the DAQmx Create Channe.vi which can only be called once the task as been completed and removed. 

I hope that makes sense, and please let me know how you get on when you can next try it out!