Use the Eye Contour Group Setup dialog to place eye-contour lines on NRZ eye diagrams. Eye contours provide additional insights into the quality of an eye diagram.

• More on eye contours

Click Measure > Eye/Mask > Adv Eye > Add Eye Contour… to open this dialog. Or, click the Add Eye Contour button in the Adv Eye toolbar.

To create a group of eye contour lines

In this dialog box:

1. In the Contour Lines field, select the lines that you want. When applied to a PAM4 waveform, the group's lines are displayed within each of the three eye openings.
2. Use the Contour Probability field to select that line values be interpreted as:
• Probability, or
• BER (BER Error Rate) for NRZ signals or SER (Symbol Error Ratio) for PAM4 signals.
3. Click Add Line to add a value for a new line. Your group can have up to 8 contour lines. Values can range from 1.0E-1 to 1.0E-18.
4. Click Close to create a group of eye-contour lines.

Up to 16 groups can be created with each group having a maximum of 8 contour lines. The Eye Contours panel that is shown in the following picture lists the eye contour groups with their source waveforms and any applied fixed RJ or RN.

To edit an existing eye contour group:

1. In the Eye Contours panel that is displayed below the waveforms, click in the list to select a group.

2. Click the panel's Setup button.

Fixed RJ and RN

Use the Random Jitter and Random Noise fields to enter fixed values of RJ and RN. To measure the RJ or RN, switch the DCA-X to Jitter Mode and perform the measurement while using a signal that has a short pattern. Or, perform the measurement using a separate instrument, such as a spectrum analyzer.

Values of RN can be entered for each eye level of an eye-contour group. PAM4 signals have four possible levels: 0, 1, 2, and 3. NRZ signals has two possible levels: 0 and 1.

Field	Description
RN 3 Value	Applies to level 3.
RN 2 Value	Applies to level 2.
RN 1 Value	Applies to level 1.
RN 0 Value	Applies to level 0.