the attached picture is a waveform chart for ultrasonic data acquired on-line, the chart shows the period from 180 to 307 second,
Is there any way to view the history ? For example: after I finish the measurement I want to see the period from 0 to 127, what must I do to roll back
It depends what you mean by 'after you finish the measurement'
A few options:
1) Just type in zero on the x axis to make the graph rescale and show the data
2) Use the chart history property node to access the data programmatically
3) save the data to a file as it is acquired so that you can view the data whenever you want
1) and 2) might need you to tinker with the chart history length to make sure it is long enough. (Right click the chart, select chart history length). Once the chart history length is exceeded, I believe the data is lost so it needs to be long enough.
Right Click on the chart and select: Visible Items> X Scrollbar.
This will allow you to scroll through the chart history.
This assumes your chart history length is greater than the amount of data that is currently being displayed.