Agilent Technologies J-BERT N4903B, Руководство пользователя, Страница: 483 / 572

Table 33
Input
Timing Errors Forward
distance
to ‘bad’
setting Backwar
d
distance
to ‘bad’
setting
1 0 3 1
2 0 2 2
3 0 1 3
4 50 0 0
5 1000 0 0
6 100 0 0
Case-2 (Calibration using an Oscilloscope)
– Connect Data Out of N4916B to the oscilloscope.
– Terminate Data Out of N4916B.
– Connect Trigger-Out of PG with Trigger-In of oscilloscope.
– Terminate Trigger Out of PG with 50 Ohm termination resistor.
– Select each of the 6 Input Timing Settings and measure the output of the
N4916B with the oscilloscope.
– Measurement has to be done checking for erroneous sampled bits, so the
oscilloscope has to be adjusted to measure at a xx0 to 111 transition of the
pattern.
– The oscilloscope has to be configured to display every measured sample
infinitely.
– Measurement time has to be at least long enough for the required target
BER (e.g. 1^-12 at a confidence level of 95%).
– A measurement is considered ‘error free’ when there are no samples taken
‘outside’ the regular signal trace.
– Selection of the optimum Input Timing setting is done as shown above for
the BER measurement.
4
Selection of the optimum Input Timing setting is done as shown above for the
BER measurement.
5
Optionally reload the previously stored instrument state
Solving Problems
9
Agilent J-BERT N4903B High-Performance Serial BERT 483