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MDVolle

L O N G graph displays?

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This may be a really rookie error or oversight but I did have it working once and can't seem to do it again...

I have data coming in from a Labjack U12 at 20/sec times four channels - I have history set to 72000 and persistence set to 3800000 - This should, in theory be about two days?

I have several short time frame graphs using the same data and they all work fine - up to a time length of 600

My graph that is intended to show a full two days doesn't work - I can't get a display longer than a time length of about 3600 - 

This makes me think I am missing something completely - if I set the time length to 200000 I get a display with two + days and dates shown in the graph window - at this sampling rate, I thought that the window (time) length would also be 3800000?

Is time window length independent of sampling rate? 

I am clearly missing something about the process and previously (on a com-user where I was lucky to sample at 1/sec) got everything to work

What Have I failed to understand?

 

Thanks

Mark

 

 

 

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3600 at 20/sec is 72000, so basically you are just seeing the history.  To access persist data you must subset.  This is to prevent you from accidentally pulling a huge chunk of data into RAM.  For a graph, the best way to subset is to use the bottom axis scaling, which is available as a variable.  So if your Y axis expression is "MyChannel", you would change it to:

MyChannel[bottomAxis.currentScaleFrom, bottomAxis.currentScaleTo]

 

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