Teledyne LeCroy WaveExpert 100H Operators Manual - Manual (Page 71)

Wave Expert
WE-OM-E Rev A
69
Eye Mode
Eye Mode is selected by touching the Eye button in the "Horizontal" menu, or by pressing the Eye
button on the instrument front panel in the Quick Setup group. When in Eye mode, all channels in
the instrument are set to display the eye pattern of their respective signals. Up to four eye patterns
sharing the same timebase can be displayed. The horizontal menu changes to reflect the unique
functions in the eye mode:
The sample mode control can be set to SEQ or CIS if option WE-HCIS is installed. The controls in
the horizontal have the following functions in the eye mode.
1. Set the horizontal scale by entering the value in the Time/Division field. The up and down
arrows increment or decrement the number of UI in steps as fine as 0.5 ps. Note that in the
CIS mode, when installed, the maximum horizontal scale is limited to 10 UI.
2. Position the eye pattern in the screen by setting the Delay value. A positive setting for the
delay moves the eye diagram to the left on the screen and a negative value moves the eye
pattern to the right. The eye pattern is centered on the screen both vertically and
horizontally using the “autosetup” function. Once the auto setup is executed, the eye
should be displayed with the crossing points at divisions 2 and 8 and the logical high and
low levels at vertical divisions 2.5 and – 2.5.
3. The Max Samples control, in general, has no impact on the acquisition in eye mode with
the sequential timebase. The value in this control should be set higher than the number of
of samples in the horizontal descriptor box, however. When the CIS timebase is being used,
the Max Samples control is unavailable.
4. Select Time or Bits by touching the appropriate button in the menu. The selected scale
factor is applied to all measurements on the eye patterns (i.e., UI for Bits and ps for Time).
5. Select the signal standard being measured in the Signal Standard field. The signal
standard sets the value in the Bit Rate field and loads any eye pattern masks associated
with the standard. The specific mask is selected and enabled in the vertical menu for the
selected channel. Note that autosetup is required to configure the instrument for eye
pattern measurements on the specific signal being tested.