xy graph with double (or more) y scales

[California_J]

Deaar all, graph made on 128x64 GLCD is attached to show-describe what I would like to do in LabView with your help ofcouse.

It shows air pressure and air humidity for 96 hours back and I would like to have something simmilar in LV if posible.

GLCD is driven by PIC18F4685, where for pressure, humidity and for hours care three diferent software buffers, each with 96 memory places.

Any idea or example how to do it would be very appreciated.

Regards, Vlado

[natasftw]

Do you need the XY graph?  It looks like that's measuring something at a constant interval.  If so, you should be looking at the graph or chart instead.  The purpose of the XY graph is to allow you uneven spacing between points.

If the XY graph is really what you need, open up LabVIEW and go to Help -> Find Examples.  Search for XY graph and you'll see "XY Graph Data Types"

Run this VI.  The first graph will show a single plot.  The second will show two plots.  From there, you should be able to understand how to make two plots.

[California_J]

Well if I am honest, I don't know what to use. X scale should looks the same, becouse I don't need there all 96 numbers for hours, also there should be some space between two points on the graph area. I was checking LV forum many times, but with no luck to find something desired.

[RavensFan]

You can right click the Y-scale and pick Duplicate Scale.  You can do that multiple times.

You can put the Y-scale on the right hand side if you right click on it and pick swap sides.

The only thing left is that you'll have to assign which plots go to which scale.  You do that withing the chart's/graph's property dialog box.

[California_J]

Thanks for suggestions. What about buffer for each plot and specially about space between points in graph/chart area?

Vlado

[RavensFan]

Buffer each plot:

You can buffer the data for XY graphs yourself.  As natastfw had mentioned, look at teh XY Graph example for the different ways of combining the data for multiple plots.  You would just need to maintain shift registers that keep the history buffer of the points you wnat to plot.

Space between points in graph/chart area:

I'm not sure what you mean by that.

[California_J]

Thanks. Space between points: Buffer has in this case 96 memory places for one variable (each meassuring result-point takes one place in buffer), if for example x scale is 190 mm long we will have between two points 2mm space in x direction. So How to get for example curve of the air pressure over complete x area (190 mm or even more).

Vlado

[RavensFan]

Build arrays that contain 96 elements before you plot those points on the graph.

You can plot data as points of various styles or not use any points at all.  You can join points with various types of lines or no lines at all.

If this doesn't answer your questions, you'll have to ask in a different way.  I have a feeling you are asking questions using a terminology that doesn't apply to LabVIEW graphs.

[California_J]

Thanks, a lot of tests with graph examples are waiting for me. Give me some time.

Vlado

[California_J]

Back again. I managed to put together temperature diagram made with chart (4 diferent temperatures). The problem is X scale, I would like to have actual time in X scale, but I am not able to do it. Below is a picture with diagram, where actual time is marked with red colour.

The question is of couse, could you help me to fix this issue?

Thanks in advance.

Vlado