Teledyne LeCroy SDA II - Manual (Page 19)

Operator's Manual
Eye Measurements
Eye Measure Dialog
The Eye Measure dialog is the principal tool for setting up Eye diagrams. Click the Setup Eye Meas-
urements button on the Serial Data Analysis II dialog to access the Eye Measure dialog.
The Eye Modes section in the Eye Measure dialog lets you choose an eye mode, either Single Eye, Dual
Eye Trans/Non-trans, Dual Eye Gated, Dual Eye FSB.
The Masks section in the Eye Measure dialog lets you select different modes for the selected standard. A
standard may define different masks for different measurement types. The Mask Margin lets you define
how much to enlarge the mask, to make sure that your signal passes the mask plus margin.
Set Up Eye Diagram
Follow these steps to define the type, shape, and size of an Eye diagram.
1. Open the Eye Measurement dialog.
2. Place a checkmark in the Enable Eye Meas. checkbox to turn on eye measurements.
3. If you want to turn off the eye parameters display, touch the Turn Off Eye Params. button.
4. In the Eye Mode section, touch the Mode field and choose an eye mode from the pop-up menu.
5. Touch the Vertical Auto Fit checkbox if you want to scale the eye pattern. These controls are dis-
abled (grayed out) if the mask is specified in absolute units (volts and seconds); that is, if the stand-
ard does not allow auto fit.
The vertical auto fit function sets the scaling of the eye pattern so that the one level is at the second
vertical division above center, and the zero level is at the second division below center. The Vertical
Auto fit checkbox is automatically checked or unchecked depending on the selected Signal Type.
Example: When an absolute mask like XAUI is selected, the Vertical Auto fit checkbox is unchecked;
however, it is checked for a normalized mask like FC1063.
Scaling for absolute mask signals is accomplished by setting the vertical scale of the input signal.
6. In the Mask section, touch the Mask Type field and choose a mask type from the pop-up menu.
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