Technical data

32 4000 X-Series Oscilloscopes Service Guide
2 Testing Performance
digital high levels. Record the oscilloscope calibrator
voltage in the Performance Test Record (see page 61).
Before proceeding to the next step, make sure that you
have recorded the oscilloscope calibrator voltage levels for
each of the threshold settings shown in Table 5.
9 When testing 4000 X-Series MSOs, use the 8- by- 2 test
connector to connect digital channels D15- D8 to the
output of the oscilloscope calibrator. Then connect the
D15-D8 ground lead to the ground side of the 8-by-2
connector.
10 Repeat this procedure (steps 6 through 8) for digital
channels D15- D8 to verify threshold accuracy and record
the threshold levels in the Performance Test Record (see
page 61). Be sure to set the thresholds with the User
softkey for the appropriate set of channels.