I have a stepper motor that is controlled by PWM. I am trying to analyze the signal coming out of the controller on an oscilloscope. Ideally, I would like to capture, maybe 2 seconds of wave form so that I can see the exact signal being used to control the signal. I am using a Rigol DS1102E oscilloscope but and I am able to capture screen shots of the waveform, but not enough for me determine exactly how the controller is operating over an entire cycle. Does anyone know of a way to capture several waveforms so that I can see the entire signal over when it runs the stepper motor?
I've got that 'scope. It sounds like you just need a bit more practice driving it. To capture a single frame set the 'scope up for "single" in the Trigger-> sweep menu.. right under "normal" and "auto". You'll then have to configure the trigger level and all such that you have a chance of triggering on what you want to see. (Sometimes you'll want to trigger on one signal and look at a different one.. or even two signals.. so you might have to use the external trigger input.) You may want to look at a lot of single shots to find the one that you want. Push the Run/Stop button to get another trace.
As far as getting waveforms into your computer. I usually just save a bitmap of the on screen picture. But you can also download a CVS file of the raw data, you've then got to have some other program to plot this data for you.
I hope that helps,