Eye Diagram on an Oscilloscope

Описание: How to capture an eye diagram on an oscilloscope using a function or waveform generator.

Steps:
1. Feed the baseband signal into channel 1 of the oscilloscope.
2. Set up the function generator to generate a square wave timing signal at some multiple of the baseband symbol rate.
3. Feed the timing signal into channel 2 of the oscilloscope.
4. Set up the scope to trigger on channel 2.
5. Fine tune the timing of the scope to show the eye at about two symbol widths.
6. Manually fine tune the frequency output of the function generator to match the transmitter baseband frequency. You typically need millihertz precision here. The timing is matched when the eye is steady on the screen.
7. Enable 1 second persistence on the scope to see more detail.