:MEASure:EYE:JN

Meas. mode:
Eye
Package License:
L-RND
Compatible waveforms:
NRZ
PAM4
Flex Apps:
FlexDCA
FlexRT
Advanced Eye Jn Commands

Command Syntax

:MEASure:EYE:JN

Query Syntax

:MEASure:EYE:JN?

Description

Performs an Advanced Eye J2, J5, or J9 measurement, which measures the total jitter associated with a specific symbol error ratio (BER). To return a measurement for a PAM4 eye, first select the desired eye using the :MEASURE:EYE:JN:EYE command. The following table lists each measurement with the BER value at which the measurement is made. Use the :MEASure:EYE:JN:SJN command to select a J2, J5, or J9 measurement. Moves the measurement result to the top of the Results table, if it is already shown on the table. The query form of the command returns the measured value.

Measurement and Associated BER
Measurement BER
J2 2.5E-3 (2.5 x 10–3)
J5 2.5E-6 (2.5 x 10–6)
J9 2.5E-10 (2.5 x 10–10)

To increase measurement accuracy, use the following steps:

  1. In Jitter Mode, measure Random Jitter (RJ) on a shorter pattern.
  2. Switch to Eye/Mask Mode
  3. Use the :MEASure:EYE:JN:RJSTabilize and :MEASure:EYE:JN:RJSValue commands to specify the short-pattern RJ result to be used for the DJ, RJ, and TJ measurements.
  4. Switch to a long pattern.
  5. Measure JN.

This Eye mode measurement can be applied to both NRZ and PAM4 waveforms.

Requires FlexDCA revision A.02.50 and above.

Requires Option 401, Advanced Eye Analysis Software license.

Measurement Identification

Avoid subtle programming errors! To ensure that the correct measurement is installed or queried, always explicitly identify a measurement when installing a measurement or querying a measured value, status, or detail. To identify a measurement, specify the measurement's source waveform (:SOURce child command). With some measurements, you may also need to specify other identifying values. Generally, when selecting a measurement using FlexDCA's GUI, if a dialog appears prompting you to select values, you should explicitly specify these values when remotely identifying the measurement. More information.

For example, to return the status of the measurement, :MEASure:EYE:JN:

flex.write(':MEASure:EYE:JN:SOURce CHAN1A')
if flex.query(':MEASure:EYE:JN:STATus?') == 'CORR';
    measurement = flex.query(':MEASure:EYE:JN?')
else:
	details = flex.query(':MEASure:EYE:JN:STATus:DETails?')
	reason = flex.query(':MEASure:EYE:JN:STATus:REASon?')

Child commands for measurement identification:

  • :MEASure:EYE:JN:SOURce
  • :MEASure:EYE:JN:RJSTabilize
  • :MEASure:EYE:JN:SJN
  • :MEASure:EYE:JN:RJSValue:EYE

Example Command Sequence

:SYSTem:MODE EYE
:MEASure:EYE:RJ:SOURce CHAN1A
:MEASure:EYE:RJ?

See Also

Common Measurement Queries