User:Steven J. Koch/Notebook/Kochlab/2009/07/28/Feedback tweaking

Steve Koch 16:02, 28 July 2009 (EDT): Figured out (or remembered from before I left) that PhreshPhotonics math needs to have a negative scale factor (using -65535 now) in order for the detector signal to be the "same" as it was before, relative to the piezo translation. This could be because the detector is oriented differently, or because the piezo is oriented differently. It doesn't really matter, but now the old feedback settings (positive setpoint, "reverse acting=T" for force clamp) are working.

I have a new project, titled "Tweaking PID"

• Data file 0. Seemed to work well for 4000 setpoint. However, on the oscilloscope, was not at 4000, but rather was at 2500. Looking at the data file, though, X is kept at 4000, with the noise going between 3000 and 5000-ish.
• Data file 001. Higher voltage. Noise is less (maybe 3500 to 4500). Again, data file shows 4000 setpoint achieved, but oscilloscope computer was showing only 2500.
• Data file 002. Changed the gain settings on the oscilloscope (to match feedbackDAQ), but it still read 2500 during acquisition, while the saved data file says 4000 (same as file 001)

Using NI-MAX on both machines, it looks like X and Sum are reading the same on both computers, even though daq2 is using RSE and steveoffice is using DIFF. This would seem to indicate that it's a stupid programming hiccup?

• The oscilloscope program reads the same on both computers. Even more evidence of some kind of programming snafu.