:MEASure:EYE:RN

Command Syntax

:MEASure:EYE:RN

Query Syntax

:MEASure:EYE:RN?

Description

Performs an Advanced Eye Random noise (RN) measurement in Eye/Mask mode on NRZ or PAM4 signals. RN is noise that is uncorrelated to the pattern and follows Gaussian statistics. Since the measurement is made on an eye diagram, the pattern itself can be of any type or length, such as PRBS31. (Jitter Mode is limited to making measurements on patterns up to PRBS16.) The corresponding jitter measurement is Random Jitter (RJ). Random noise is displayed in the current vertical channel units. If the measurement is already on, the measurement listing is moved to the top of the displayed results table.

If you experience difficulties measuring a PAM4 signal, confirm that the signal-type setting is set to PAM4 with the :CHANnel:SIGNal:TYPE command.

To increase measurement accuracy, use RN stabilization:

1. In Jitter Mode, measure Random Noise (RN) on the signal while using a short pattern.
2. Switch to Eye/Mask Mode
3. Use :MEASure:EYE:RN:RNSTabilize to turn on RN stabilization and :MEASure:EYE:RN:RNSValue commands to specify the short-pattern RJ result measured in step 1.
4. Switch to a long pattern.
5. Measure DI, RN, and TI.

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:RN:

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

Child commands for measurement identification:

• :MEASure:EYE:RN:SOURce
• :MEASure:EYE:RN:RNSTabilize
• :MEASure:EYE:RN:RNSValue:LEVel1
• :MEASure:EYE:RN:RNSValue:LEVel0

Common Measurement Queries

• :COUNt?, :LOCation?, :MAXimum?, :MINimum?, :MEAN?, and :SDEViation? common measurement queries.

Example Command Sequence

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