Almost there...but I have an error!

[Bethany]

I know I have posted similar programs before, but I took the while loop out of digital.vi and made a couple other changes. When I run voltagecontrol.vi, and press the stop button to move beyond the while loop, an erro pops up and it tells me that I need to either increase the amount of time before it times out or increase the sampling rate. The error occurs at the DAQmx Write.vi in digital.vi. I tried using the timing control in DAQmx, but it wasn't working (as well as trying a number of other things to fix the problem. After the error occurs, I press continue, and what I want to happen does. (as opposed to before! So it's a good start) But I would like to be able to press the "stop" button on voltage control.vi, and move right on to the next digital output, without that wait time involve. What do I need to fix in my program(s)??

Thanks for any help!

Bethany

[devchander]

Hi bethany,

Post ur VI as a development distribution, go to save with options and select development distribution to save as a library file.

all ur sub VI's are missing.

Its not clear if u are dong any data acquisition in ur sub VI's

[Dynamik]

Hi Bethany,

      The error you describe implies a multi-sample-write is being attempted in digital2.vi.  What's wired to DAQ mx Write\"data" in digital2.vi?

D. 

[Bethany]

It is the exact same thing as digital.vi that was attached - I just was trying to put it into a different vi earlier to see if that was the problem.  Can you see a problem with the wiring in digital.vi??

Thanks for your help!

Bethany

[Dynamik]

Hi Bethany,

      I don't see anything wrong, but I haven't used DAQmx much (yet. 🙂 )

The attached code implements the original "voltagecontrol" logic, but using a single reference to digital.vi. 

If this doesn't work, perhaps you can share the error code?

BTW, It uses an event-structure to trigger loop on control updates!

cheers

Message Edited by Dynamik on 11-12-2005 09:24 PM

[Bethany]

Thanks Dynamik,

It does work well (it does not pause as it did with my rendering, and it works well in all regards! Finally!), although it still shows error code -50103 at the end... (the same error that was showing up for me previously) Is that a problem?

Thanks,

Bethany

[Dynamik]

Hi Bethany,

      Sorry, I can't run your code to reproduce the error (no hardware.)  I do recommend you determine the source of the error, but I'm not a good resource for DAQmx.  I notice that DAQ Assistant returns a task ID.  Perhaps that task should "cleared" before a subsequent call to DAQ Assistant.

Wish I could be more help!    

Message Edited by Dynamik on 11-15-2005 03:19 PM

[e-Cash-Money]

Hello Bethany,

The 50103 Error indicates that you are trying to use a resource on the board that is already being used.  This article has a good description of what is going on.  This error is a problem because it means that your Task will not be able to be executed due to the reserved resources.

I hope this helps!

[jwhite]

There is one thing wrong with that article, however.  It assumes that when you run independent channels that you will be sampling each channel at the same rate.  I tried to incorporate several channels into the same task, but when I try to configure each channel it makes these changes to ALL of the channels in my task?  How do you get around this?  I need to sample each channel at different rates, plus on some channels I want to use triggering and on others I don't.  No what?

[jasonhill]

jwhite,

As explained in the article (and in another thread), you cannot sample different channels of the same multiplexed device at different rates.  This is not a limitation of LabView, but rather a limitation of the electronics.  Multiplexers are not bad things.  They allow us to sample dozens of channels using just one A/D device, thus saving us a lot of money.

Message Edited by jasonhill on 02-14-2006 03:21 PM