2 ratings:

4.5 out of 5

Rate this Document

How Can I Control Which DAQmx Task is Running?

Primary Software: LabVIEW Development Systems>>Full Development System
Primary Software Version: 8.5.1
Primary Software Fixed Version: 8.0
Secondary Software: N/A

Problem:
I have an application where I would like to continuously obtain data from 2, or more, Data Acquisition (DAQ) channels, and each channel at different sampling rate. To acquire each channel at a different rate, I know I need to put each channel in a separate task. How can I switch between the tasks to gather data on each of my channels?

For example, let's say I have two tasks, Task 1: reading data during 1 second at 20 kHz and Task 2: reading data during 0.5 second at 10 kHz. How can I manage to start Task 2 when Task 1 is finished?

Solution:
It is possible using DAQmx Control Task VI. This lets you manually change the driver state without having to fully traverse the state model as would be required if you used a combination of Start Task VI/Stop Task VI. Basically, this way is the only one to control which task is active and control in which state is the task.

 

To illustrate this solution, please find in attachment an example VI.