Produce XY graph of pressure for each turn of crankshaft

[zvarurban]

Hello,

I would like to produce XY graph of pressure for each turn of crankshaft. There are two different analog pressure signals that are measured and two digital signals that are acquired from crank angle encoder (TRIG and CAM). Output of FPGA Vi are both pressures and angle. Host VI, running on PC transforms fixed point signal of pressures to double, divides angle by factor 10, applies formulas to pressure signals and shows the graph. 

The question is why it does not show the pressure for each turn? On a chart pressure/angle I set fixed boundaries for angle (0-360°).

Thank you very much for your help.

Used equipment and software:

- cRIO 9024

- Analog module: NI 9223

- Digital module: NI 9411

- LabView 12

[Dennis_Knutson]

Double click the express XY Graph and see if you've got it set to Clear data on each call.

[ValkoA]

Hi and welcome to NI forums!

for this purpose allow me to recommend the Polar Plot fuction in the picture library. This will let you easily create a polar plot based on magnitude and phase. This code:

will create this plot image:

Let me know what you think of this.

Kind regards: