Mulitple analog out tasks

[KinnaDaniel]

I have a question about analog output generation with DAQmx and LabView 7.0.

I have a NI PCI-6733 analog out card and I want to start multiple task on that card. For example I will begin with generating a continous sine signal on one or more physical channel and after a while output a finite noise signal on another physical channel, but when I try to start the second analog out tasks I get error message -50103 "The specified recource is reserved".

Is it not possible to start two separate analog out tasks the way I want? If so, what solution shall I use to handle this kind of application? I want to use the eight analog out channels separately and not depending on each other.

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Daniel Olsson
System Architect
Endevo
Sweden

[Tom_W_[DE]]

Hi Daniel-

As you have noticed there isn't a way to run seperate analog output tasks on your board concurrently.  All operations must be grouped into the same task, so you are left with a choice between two options.

First, you can simply write full buffers for all of the channels you will output.  This method works well if you know the amount of time or number of samples required for the continuous output at the beginning of operation.

If you would like to change the operation based on some user input or other condition then the alternative is to stop the overall task, add channel(s) to it, rewrite the output buffer data, and then restart the task.  I have attached one way to perform this second method to this message.

Hopefully this helps-