Hi all,
I am currently using a USB 6009 to control a stepper motor and acquire data from the photodiode at the same time. The USB provides the stepper motor with the signal to rotate to a particular angle as specified by the user (using an analog output) and in the process it collects data at every point from the photodiode using an analog input until the final angle is reached.
The photodiode separately was tested on the oscilloscope and produced a straight line on the screen that changed position up and down depending on the intensity of the light shining at it. The photodiode was then tested with the USB using MAX (Continuous, RSE mode with 1kHz sampling rate and 1000 samples) and an oscillatory behaviour was observed. The anolog input exhibted a wave oscillating between 1 and 1.8V. The wave again shifted up and down depending on the intensity. Should the photodiode oscillate like this and if not can someone explain to me why it is showing this characteristic when connected to the DAQ device?
Thank you
Myriam
