waveform chart

[shaunmarsh123]

hi,

i want to make a chart recorder which  display incoming data with a speed of 125 mm/s and 25 mm/s .. so how can i achieve this ?

[GerdW]

Hi shaun,

do you really want to make your chart update dependend from your screen resolution and screen size???

What if your user replaces a small 15" screen by a huge 30" screen? Should the chart change its update speed then???

Or do you want to control some "real hardware" chart printer?

[Ben]

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@shaunmarsh123 wrote:

hi,

i want to make a chart recorder which  display incoming data with a speed of 125 mm/s and 25 mm/s .. so how can i achieve this ?

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Oddly, I was asked to do something similar being presented with an industry standard test that relied on an old chart recorder. In my case I studied the plots for the faster rates and guesstimated the pen speed, then fudge the number up a bit to choose an interface that was fast enough. Then I exposed the sample rate for the scientist to judge for themselves what was  fast enough sample rate to trust the new hardware to do what the old chart recorder did. 

But that was jus the start!

Spoiler

The old spec that relied on the chart recorder, had instructions to watch for reading that were negative and if found, the curves were to be examined using a magnifying glass. If "area" could be seen between the plot and the zero point, the device failed. Go ahead and translate that part of the spec!

Spoiler

I wrote code to calculate the integral off all portions that were negative and compared that with a limit specified by the scientists. It took them months to come up with a number!

Ben 

[mjrivera]

Hello,

What acquisition devices are you using? I am asking you this because this has to do with the sample rate and the amount of samples that you are acquiring.

[mjrivera]

Hello,

What acquisition devices are you using? I am asking you this because this has to do with the sample rate and the number of samples that you are acquiring.