oscilloscope time/div volts/div

[ylazybug]

Hello, I/m building a virtual oscilloscope but I am currently unable to use the time/div, volts/div knobs like a real oscilloscope because the x scale and y scale changes for each point. To illustrate, if I were to change the value with the volts/div the vertical size(?) of the wave changes with the scale but when using my vi, the wave remains the same and only the scale changes which makes it slightly difficult to notice the change. Not sure if I made it clear, but I hope someone will get what I want ;(

[Bob_Schor]

You are changing the scale of the 'scope, but you are not changing the gains of the "horizontal" and "vertical" circuits.  I'm not sure what you mean by a "Division"  -- in most oscilloscopes, this corresponds to the thicker lines on the Graph, so I'd describe the Graph you drew as "5 V/div".  Suppose you have a sinusoid with an amplitude of 1 v.  At 5 V/div, it would go up one small line on your graph.  If you changed the V/div to 1 V/div, you would need to amplify the signal by a factor of 5 before plotting it -- I don't see this in your code.

I notice that you are checking (and setting) the graph properties with every pass through the While loop.  Most of the time, you don't change the Controls, so you don't need to change the gains (of the horizontal and vertical "amplifiers") or Graph scales.

Do you know about the LabVIEW Event Structure, usually used to "do something" when a Control's Value changes?

Bob Schor

[ylazybug]

I'm trying to use the event structure! I'll be right back thanks