grapghing Long-term Graphing

[Jeyjey]

Hello,

I am about to start a project where I need to be able to view a force-displacement, force-time and displacement-time graph on the DAQfactory software. I will have 3 x Labjack T7 to set up 9 stations. So I will be looking at 3 graphs per station which mean I will have a maximum of 27 graphs running in the software. I need to be able to test up to 28 days (data-logging and graphing) and it could sometimes be with multiple stations simultaneously. I primarily want to press a button and start the testing, then all the graphing from the start till the end (up to 28 days) needs to be viewable on the page. Do you see this as a limitation in the software?

Look forward to hearing from you.

Thank you!

[AzeoTech]

DAQFactory should not have an issue with this.  At what interval will you be acquiring the data?

[Jeyjey]

Each graph will be updating at an interval of 1 data-point per second. So I pretty much want the X-axis (time) to be increasing until it shows the whole 28 days worth of data-points. I believe this won't be an issue?

[AzeoTech]

So you want the bottom axis graph to be zoomed initially, then expand to 28 days as new data comes in?  This is not an issue, but does require you to change the X axis scaling parameters accordingly and not use the Time Width feature

Also note that 1 second data over 28 days is a lot of data, 2.4 million data points in fact.  Because of memory limitations, you will need to use the Persist feature of the channels to offload some of the data.  Accordingly, you will need to set the Y Expression of the graph to subset so that persist data is accessed.  For example:

myChannel[bottomaxis.currentScaleFrom, bottomAxis.currentScaleTo]

Change "myChannel" to the name of your channel.

The "bottomAxis.currentScaleFrom" and To are variables of the graph that return the current scale from / scale to values used in generating the graph.

[Jeyjey]

Hi Guru,

That is exactly what I want to do. Thank you for the advice.

I will have a go at doing this.