how to read from DAQ in different time intervals

[fyork1978]

Hello,

I am currently using LabVIEW 2010. I am new to LabView.

I have 9 thermocouples I want to record the temperature from and create a graph.

For one graph I want to graph the data every second for the duration of about 1.25 hours. For the other I want to record and graph the data every 2 minutes for a duration of 30 minutes. The temperature then would be ramped up in an oven and set to a higher temperature. When it is stabilized, recording of the data again will begin again at intervals of 2 minutes for the duration of 30 minutes.

The first is only to see the real time temperature variation while the program is recording and running. The second graph and data is what I will use to analyze.

What I need help in is finding out how you can read from the DAQmx at two different time intervals. I tried two parallel loops with each one graphing the two separate graphs I need with a delay time. Those two parallel loops where then surrounded by another while loop. The result is that the outside loop waits until both loops are finished so I do not get the correct results for the real time data graph.

Is there a way to call on the DAQ data you need at the time interval you desire? Any suggestions to solve this problem? Thank you for your time and help.

[_Bryan]

You are on the right track.  Sample the data at the fastest rate and send it to the 1st graph.  For the slower graph, take a sample from the faster data at your desired time interval.  You could use a timer and a case structure for something quick and easy and still have everything run in the same loop.  You could use two loops running at different speeds, it is just a little more involved and a few other things to consider. 

[Karl-G]

I would agree with Bryan. Your DAQ will need to sample at the fastest desired rate and then the slower update will have to be achieved through software.