Originally Posted by professor

Absolutely! The CIS computer will generate a nice steady square wave if you just turn the ignition on without the engine on. That signal will stay steady as it is a reference signal. Once you turn the engine on, you will have to wait for operating temperature so that your reading is reflective of what the O2 sensor is detecting. At this time you will see the signal drift a little, the top of the signal gets wider when there is a rich mixture being called for and the bottom gets fatter when a leaner mixture is called for ( you can see these on the scope of course, otherwise use a voltmeter and watch the voltage increase for a richer mixture and decrease for a leaner one). The ratio between the upper side and lower side of the signal is your duty cycle. Basically how much of the whole cycle was dedicated to the upper side. If the signal is exactly the same at the top and bottom then you have a 50% duty cycle for example. With a voltmeter you should get half of what your battery is generating if you are at 50% duty cycle.
Does that help?