Plotting Data on a fixed time axis from left to right

[Stuart Wilson]

I am plotting data on a Historical Trend graph from the DSC palette. I receive the data from a plc throughout the course of a production shift. I would like to have the start time of the shift (07:00) on the far left of the x-axis and the end time of the shift on the far right (15:30). I would like to plot the data from left to right as the shift progresses. Is this possible? How do I format?

Many thanks for any input,

Stuart Wilson

[Mark Mutton]

I am not really sure if I know exactly what you are talking about, but if you simply format your graph to absolute time you can specify start data and end time. In your block diagram if you data is recorded every (1 min) then you can simply create a 2d array that has your data corresponding to the correct increment of time.

[PNHorn]

Hi Stuart,

All you need to do is place down a waveform chart and then modify the properties slightly in order to achieve this. If you right click and make sure autoscaling is turned off on the x-axis first of all, then go into the properties page and change the x-axis formatting to absolute time then you will be able to plot data with the actual time according to your system clock.

The only problem you have now is that there probably isn't enough room on the chart to plot data for the entire time between 09:00 and 15:30 depending on how often you want to sample. The default number of data points to keep in the chart is 1024. Therefore if you try and change the max and min values to 09:00 and 15:30 then it won't allow you to set that up as it doesn't think you have enough room there. Right click on the chart again and go down to Chart History Length. Increase this number to a large enough number and then you will be able to set the start time to 09:00 and the end time to 15:30 and as long as autoscaling is turned off this will not change.

Hope this helps, please find the attached example which will plot random numbers to a chart once a minute and the chart will plot data between these times.

Best regards,

Peter H.

Applications Engineer.
NIUK.

[flbai]

HI Peter

you are so great thank you!

That is helpful

[flbai]

Hi peter

I saw the time axle value is 08:00-14:30

can the axle value auto change to the real test time(computer time).

how to do it.

[flbai]

hi Peter H - NI

It seems difficult to change the time freely

my time axle begine at 08:00, i cann't change this time , but i can adjust the end test time.

why the begine time is 08:00. can i change it and how?