Just finished some recent engine testing. Here's a screenshot of the short run so people can see more clearly than on the video perhaps.
After the run is done, you can drag a vertical cursor across the lower horizontal axis which is time. In the lower left of the screen, you'll get a numerical readout of the selected parameters at that time in the run.
The color key up top shows what each parameter is.
RPM is displayed on the left vertical axis (red trace), AFR on the right vertical (green trace).
You can turn off any parameter to de-clutter the screen if desired.
You use the Fetch Values button to pull the values out of the ECU which you can review or print in a compact format.
You can also log in text instead of this graphical format to see every single data piece in great detail.
This run shows a slow opening of the throttle to WOT with the engine under propeller load. It reached approximately 2400 rpm here. Notice the AFR got quite rich above about 2100 rpm. We'd then go in with the programmer and reduce the rpm fuel values there to lean the engine back towards best power (about 12 to 1 AFR).
The lean spike when the throttle is closed is due to a fuel cut being set at fully closed throttle, just done here to check the wideband O2 sensor calibration.
You can see where the data logging can be highly useful for tweaking the values or spotting an issue with the programmed values.