B&K Precision 2532B - Manual - Manual (Page 170)

170
D
C
A B
Sin
θ=A/B or C/D where θ=phase shift (in degrees) between the
two signals from the formula above, you could get:
θ=±arcsine (A/B) or ±arcsine (C/D)
If the main axis of the ellipse is at II and IV quadrant,
θ must be
in the range of (0-
π/2) or (3π/2-2π). If the main axis is at I and III
quadrant, θ must be in the range of (π/2-π) or (π-3π/2).
Analyzing a Differential Communication
Signal
You are having intermittent problems with a serial data communication
link, and you suspect poor signal quality. Set up the oscilloscope to show
you a snapshot of the serial data stream so you can verify the signal levels
and transition times.
Because this is a differential signal, you use the math function of the
oscilloscope to view a better representation of the waveform.