No data points in xy graph

[SBTF]

Hi everyone,

I'm relatively new to LabView, so please don't shoot me.

I have created a VI to plot and log a weight, a RTD, and a humidity signal (SBTF_v6.vi).

This VI works fine (if there are possibilities to make the VI more efficient, feel free to give tips).

Now I'm trying to add more RTD temperature signals in the 'Temperature measurement' while loop.

After reading several messages on the forum and going through the examples, I'm trying to create an XY graph without the Express VI Build XY graph (see RTD temperature.VI).

This would allow me to plot all temperature signals on one XY graph.

In the RTD temperature.VI I can create the graph for a single RTD signal, however I can not see the data points in the graph. 

By contrast, the X and Y axis do change their scales (autoscale option on) when the temperature raises or drops. 

Apparently I am missing something fundamental (e.g. LabView knowledge, but I am going through the LabView Basics I: Introduction course manual at the moment).

What am I forgetting in the RTD temperature.VI?

Thanks a lot!

Carlo 

[Greg_S.]

Hi,

You can use Express XY graph and have all your signals in one graph if u use before entry of Express function, the function 'Signals Bundle' not sur in english version ? from express palette.

Second why in your other VI with simple XY graph you don't have a signal is because XY graph doesn't keep in memory your points so you have to code by yourself using shift register.

You graph only plot one point at time.

You should take a look at Graph example, and some tutorials on this website.

[MK_MTEngineer]

Hello!

You are plotting only one datapoint a time and your XY-Graph only shows you connected datalines (you can change this in the "Plot" property of the graph). A XY-graph stores NO history, so you have to connect it with the whole history within an array. Look at the random.vi. Hope i could help you so far!

Best regards,

Michael

...mhh was a littlte to late

[aeastet]

Here is how you would do the same thing for multipule xy pairs. You need to  bundle them in a cluster and then add them to an array. I made a few slight adjustments to MK-MTEngineer's vi.

[Nico_support]

Hello SBTF,

Have you been able to fix your problem?

Nico Lammens

Applications Engineering

NI Support