Kiethley 6487 pAmmeter LabVIEW real-time Current vs Time graph

[lee3ma]

Hi I am new to LabVIEW and I am trying to have the program generate real-time graph of the measured current, reading directly from the Kiethley 6487 pAmmeter. I am using the LabVIEW Kiethley 648x series instrument driver. The driver currently collects the data and displays it on the XY graph after all the data has been collected. I have read that I need to have the data plot point by point in a "greedy" loop but I am not sure how to modify the driver code in order to do that. Thank you!

[cbutcher]

Your loop doesn't necessarily have to be "greedy" (a term usually applied to a loop with no waiting functions or functions taking a specific time - like DAQmx Read, for example) but if you want to update an indicator (graph) during acquisition, it must be inside the loop.

Depending on your existing code structure, that might be very easy or more difficult.

If you're able to use a Chart (instead of a Graph) it might be easier (charts store history).

Otherwise, look at using a Shift Register to store your history and something like Build Array set to Concatenate mode (right click to change).

If you share your code, we can give an example of the change you probably need.