:MEASure:EYE:PAM:VECLosure
Command Syntax
:MEASure:EYE:PAM:VECLosure
Query Syntax
:MEASure:EYE:PAM:VECLosure?
Returns the measurment for the eye specified with :MEASure:EYE:PAM:VECLosure:EYE.
Description
Returns the PAM4 Vertical Eye Closure measurements (VEC) located in the Eye Mode Results measurement results. Displays the measurement if it is not already shown on the table. The query form of the command returns the measured value. Select the eye measurement to be returned using the :MEASure:EYE:PAM:VEClosure:EYE command.
The Eye mode's Vertical Eye Closure (VEC) PAM4 measurement is a measure of the ratio of the ideal eye opening (separation between the average levels surrounding the eye) to the measured eye height of that eye reported in dB. This measurement can also be used for NRZ coded signals. VEC is measured for each of the three PAM4 eyes. The higher the result (decibels) the more the eye is closed. This measurement is IEEE 802.3ck compliant.
Eye Height is measured with the same algorithm as is used for the PAM Eye Heights measurement (:MEASure:EYE:PAM:EHEight).
Use the :MEASure:EYE:PAM:VEClosure:REFerence command to select the reference for the VEC measurement: Optical Modulation Amplitude (OMA) or Eye Opening.
Use the :MEASure:EYE:PAM:VEClosure:DEFine:EOPening command to define the eye opening: zero hits or at probability.
The IEEE method of measuring VEC in Eye mode would be to select the Reference to Eye Opening and the Eye Opening Definition to At Probability with a probability of 1.0E–5,Keysight recommends using Jitter Mode's PAM VEC measurement (:MEASure:PEYE:VECLosure) whenever possible.
Requires FlexDCA revision A.06.60 and above.
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, :
flex.write(':SOURce CHAN1A')
if flex.query(':STATus?') == 'CORR';
measurement = flex.query('?')
else:
details = flex.query(':STATus:DETails?')
reason = flex.query(':STATus:REASon?')
Child commands for measurement identification:
:MEASure:EYE:PAM:VECLosure:SOURce:MEASure:EYE:PAM:VECLosure:REFerence:MEASure:EYE:PAM:VECLosure:DEFine:EOPening:MEASure:EYE:PAM:VECLosure:DEFine:EOPening:RJSTabilize:MEASure:EYE:PAM:VECLosure:DEFine:EOPening:RJSValue:EYE:MEASure:EYE:PAM:VECLosure:DEFine:EOPening:RNSTabilize:MEASure:EYE:PAM:VECLosure:DEFine:EOPening:RNSValue:LEVel1:MEASure:EYE:PAM:VECLosure:DEFine:EOPening:RNSValue:LEVel0:MEASure:EYE:PAM:VECLosure:SOURce:MEASure:EYE:PAM:VECLosure:SOURce