Waveform chart

[JDonne]

Hi all, I am a beginner when it comes to Labview so apologies if this question has been covered. I am using labview 8.5. I have been asked by the boss to build a labview which will take temperature measurements.  I am trying to acquire two samples at a specific times (every 10 second, 15 second depending on what is decided). This is required as we might need to take samples over 1-2 weeks

The vi program I have designed so far will take in the measurements thru' the DAQ, then average the sample out using the "Mean". It is then brought into a collector and displayed onto a graph. This is where I am having the problem.

In the DAQ properties when the samples to read and rate ( HZ) are equal the graph updates in real time, however when i change these setting the graph dsplays the results out of sync with real time.

What I am looking for is the Temperature graph to only display the result taken at a specific time (e.g. 10 sec, 15 sec) and not for the continuous time and also to keep it at real time.

Thanks and I hope somebody can help

Regards

JDonne 

[shjukheter]

I can only suggest you at the moment to look into the help of DAQ Assistance. Especially on stop option and then in timing palette to define stop time with some sort of logic. Also, put all the graphs and indicators that you want to display for only specified time into case structure and use the timing options to enable that case.

[Dennis_Knutson]

Specifically, what you need to do is change from continuous samples to N samples and place a wait function inside the loop. This wait will determine how often you do a read.

The chart does not reflect actual time because you are not providing it. You have stripped all time information from the signal by taking the mean. You can use a property node to set the offset and multiplier for start time and increment respectively. See the shipping example called Real-Time Chart.

[JDonne]

All, thanks for the information