B&K Precision 2552-2559 - Manual - Manual (Page 139)

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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 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.
To activate the differential signals connected to channel 1 and channel 2,
follow these steps:
1. Press the CH 1 button and set the Probe option attenuation to 10X.
2. Press the CH 2 button and set the Probe option attenuation to 10X.
3. Set the switches to 10X on the probes.
4. Press the AUTO button.
5. Press the “MATH” button to see the Math Menu.