Custom drawing over a waveform chart

[EFFE-GI]

Hi all,

I want to visually show the upper/lower limits in a chart, keeping its original scale. For instance, I've a time/pression plot (0-10 bar) and I want to show the valid pressure is between 8-9 bar.

Is there a way to show two lines (at 2 specified Y values) or change the background or, more generally, to access the chart canvas and operate over it?

Thank you

--

Nicola

[lraynal]

QUOTE(EFFE-GI @ Feb 28 2008, 10:25 AM)

Hi all,

I want to visually show the upper/lower limits in a chart, keeping its original scale. For instance, I've a time/pression plot (0-10 bar) and I want to show the valid pressure is between 8-9 bar.

Is there a way to show two lines (at 2 specified Y values) or change the background or, more generally, to access the chart canvas and operate over it?

Thank you

--

Nicola

Perhaps you should think about using a Graph XY !

It's a bit less easy to use, but you control it much better.

And if you want to stay with a Chart for the "chart history" facility, you can use it to store the values, and then use a Graph XY to show the values in you front panel !

Laurent

[EFFE-GI]

QUOTE(lraynal @ Feb 28 2008, 01:31 PM)

Perhaps you should think about using a Graph XY !

...

Laurent

Thank you for your answer, Laurent. I'll give your option a try...

--

Nicola

[torekp]

What I usually do is just add two more plots to the graph, set their plot names to "Min P" and "Max P", and use distinctive line-and-point-style combinations. For example, use lines without points for the min and max, and a line with points (or just points) for the latest reading from the sensor.

There may be a smarter way. But I don't know it.

[LAVA 1.0 Content]

QUOTE(torekp @ Mar 4 2008, 11:39 AM)

What I usually do is just add two more plots to the graph, set their plot names to "Min P" and "Max P", and use distinctive line-and-point-style combinations. For example, use lines without points for the min and max, and a line with points (or just points) for the latest reading from the sensor.

There may be a smarter way. But I don't know it.

I use the approach outlined by Pual as well. This lets me illustrate when changes to the limits occur and allows zooming etc without having to account for scale and range changes.

Ben