How do I get a chart to show the actual time with blocked data??

[vincent.deeney 768]

I am currently working on a program that reads the voltage off of a system with a pulsitile quality. The hardware is not national instruments (I know, not smart, but) so I am taking all info in blocks that cover 3 seconds so I can preform some averaging and frequency checks on it. I want to graph the information over a given period of time but can not get it to go under the proper time. Property Nodes have not worked correctly as I have followed the example in Fund>Charts>Realtime chart. Even with a max of 30 and a min of 0, the chart is ranging 30707 seconds and increasing exponentally. Per Scan I am taking 600 samples and running at 200Hz. Any ideas on how to fix this problem?

[Rob Cole]

You might try using an XY Chart. The input to this chart is an array of clusters. Each cluster contains an X value and the associated Y value. In this way, you can control the X axis completely - it only shows the values that you input.

Rob

[Lab Viewer]

I don't know exactly how long does it takes, but you can reset the chart after each scan (to do this, you have to give it an empty array as input)

[Greg_McKaskle2]

> I am currently working on a program that reads the voltage off of a
> system with a pulsitile quality. The hardware is not national
> instruments (I know, not smart, but) so I am taking all info in blocks
> that cover 3 seconds so I can preform some averaging and frequency
> checks on it. I want to graph the information over a given period of
> time but can not get it to go under the proper time. Property Nodes
> have not worked correctly as I have followed the example in
> Fund>Charts>Realtime chart. Even with a max of 30 and a min of 0, the
> chart is ranging 30707 seconds and increasing exponentally. Per Scan
> I am taking 600 samples and running at 200Hz. Any ideas on how to fix
> this problem?

The easiest way to fix this, if you are using LV6, is to us
e waveform
charts. This way you are wiring timestamp and dt to each waveform
chunk. The chart will automatically start showing date and time and
can be customized in the X Scale>>Formatting dialog.

If you are not using LV6 or do not want to use the waveform datatype,
you can open the formatting dialog and set the dt to match the timing
between adjacent points. You can also set the t0 to the initial point
time. The same points can also be set using a property node.

Greg McKaskle