Tektronix OM4006D, User Manual

Page: 161 / 205

Appendix E: Equivalent-Time (ET) oscilloscope operation
7. If the green trace in X-Constellation is elliptical:
Click Stop .
Type CorrectX in the separate Matlab Application Window.
Copy and paste the resulting pHyb statement before DispCalEllipses in
the Matlab Engine Window in the OUI as shown below.
8. Click Run . The green trace should now be circular. If it is not, repeat the
procedure one time.
Procedure to inspect and correct the Y-polarization calibration (ET).
1. Move the input fi ber to get most of the signal on RX channels Y-I and Y-Q.
Tape it down.
2. Click Single on the Oscilloscope.
3. Click Run on the OUI.
4. Observe that the ellipses are displayed on the Constellation plots. Right now
only the Y-constellation has signal. The green trace should line up with the
blue circle in the Y-constellation plot.
5. If the green trace in Y-Constellation is elliptical:
Click Stop .
Type CorrectY in the separate Matlab Engine window.
Copy and paste the resulting pHyb statement before DispCalEllipses,
replacing any other pHyb statement.
6. Click Run . The green trace should now be circular. If it is not, repeat this
procedure one time.
OM4000D Series Coherent Lightwave Signal Analyzer 137