How to clear a waveform?

[Cutter]

I am using Labview 6.1 and am using a DAQ Board to collect data.  I am plotting the data by sampling one data point on each loop iteration.  Each time the data is plotted on a waveform graph.  When I stop the program the waveform stops moving, when I start the program it appends the waveform on the screen.

How can I erase, or visually clear, the data on the waveform when the program first starts?  It would also be nice to reset the time on the x-axis of the plot.

[Will.D]

If you create a property node for the waveform, then select "History Data", and then wire an empty constant to it, that will clear your graph - including resetting the x-axis.

[Cutter]

Okay, so I right-clicked on my Waveform Chart in the block diagram and I selected Create > Property Node.  I then right-clicked on the Property Node and selected Properties > History Data.  I then right-clicked on "History" on the Property Node and selected Create > Constant.  I left the constant as zero and placed the property node and constant outside the loop.

It doesn't clear the chart or reset the axis.  Did I do something wrong?

[Will.D]

The only thing I can think is if you had the history clear executing after your loop... Just to be sure, it should look like the image.


Wire the error out of the property node to the wall of your loop to make sure it is executed before your loop starts.

Message Edited by Novatron on 08-03-2005 03:42 PM

[Deepak Arora]

How do we do this for Lab View 2010 SP1?

Thanks,
Deepak Arora

[RavensFan]

The same way.

Have you tried it?

[satish_21]

Cutter,

I guess, you haven't changed the property node for write. Right click on property node and select Change to write. Refer the screenshot. Once you do that, wire the

constant to the input. And call this property node at the begining/end, based on when you want to clear the data.

Satish