HP 37717C Calibration Manual page 196

Figure 3-35
Figure 3-36
Performance Tests
STM-1 Transmitter Output Waveshape (Options US1, [US5], A1T, [A1U],
A3R [A3S], 120)
STM-1 All Ones Pattern
STM-1 All Ones Mask
CMI All Zeros Waveshape
7. Select PATTERN [ALL ZEROS] on the OTHER DEBUG FUNCTION display.
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