HP 54750A, User Manual, Page: 131 / 478

Eye , Mask and Eyeline Mode Measurement T utorials
Making Eyeline Measurements
(HP 83480A Option 001 only)
N O T E
When the e yeline software rst boots up , the program instructs you to adjust for a valid trigger . Once
you proceed past this point in the program, you must not adjust the trigger level outside the valid
range . If you do , the instrument will lock up . T o resume operation:
c ycle power o and on, or
readjust the trigger level to within the range established earlier
Eyeline mode is not compatible with
N NNNNNNNNNNNNNNNNNNNNNNNNN
2-12 GHz or
N NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
2-12 GHz Gate triggering bandwidth.
The software provides two modes .
1. The eye mode displays a standard eye diagram and gives the user
complete control of the pattern generator .
2. The eyeline mode puts the pattern generator in remote and executes the
line mode operation.
N O T E
Measurement rate is strongly inuenced b y data pattern type and length.
Instrument throughput in eyeline mode is dominated by the rate at which
valid triggers are generated by the pattern generator . This is a function of
the data rate , pattern length, and pattern type . The highest throughput is
achieved with a zero substitution 2
7
or mark density 2
7
pattern. Longer
pattern lengths are acceptable , but will reduce throughput because only one
data point is measured per an entire pattern. Long PRBS patterns are not
recommended because they result in the lowest throughput.
P attern generator settings can be adjusted prior to running the eyeline
program or by halting remote control of the pattern generator by pressing:
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