How do I make a waveform chart track X-axis as relative time?

[Paul@BSH]

I want to start recording temperatures at time (x-axis) = 0. Then increment by taking readings once a minute and charting them. I want the x-axis to be user settable to display 1 min increments, or 5 min, or 10 min.... I have been playing with x-axis multiplier and offset property nodes, but it doesn't seem to work - I always end up with a large number(I guess stemming from Jan 1, 1904...). Any suggestions?

Thanks - Paul

PS - running LV8.2 on windows XP.

[Xaq]

Paul-

I was experimenting with the behavior you described, but doe to the nature of the Waveform chart, you cannot programmatically change the chart history length. My solution was to use a waveform graph and just display a subset of gathered data each iteration. the VI calculated teh number of samples/second and then finds the number of samples to display based on how many minutes worth of data you want to see.

Your idea of using the X-scale offset and multiplier will not work as it only scales and offsets the x scale, but will not influence the data being displayed.

Xaq

[james_p_martin]

Hello Paul,

Have a look at the Real time Chart in the NI examples folder, that may help.

Regards

James