:MEASure:AMPLitude:RINoise

Meas. mode:
Jitter
Package License:
L-RND
Waveform type:
NRZ
PAM4
Flex Apps:
FlexDCA
RIN Commands

Command Syntax

:MEASure:AMPLitude:RINoise

Query Syntax

:MEASure:AMPLitude:RINoise?

Description

Moves the Relative Intensity Noise (RIN) measurement of optical signals to the top of the Amplitude table. Displays the measurement if it is not already shown on the table. The query form of the command returns the measured value. RIN is a measure of the noise-to-signal ratio of an optical source. Because this is a measurement specific to an optical signal, the Jitter Mode's Amplitude panel only lists the RIN measurement when the channel units are set to Watts.

PAM4 Waveform?

For PAM4 waveforms, use this recommended (identical algorithm) command instead:

Use the :MEASure:AMPLitude:DEFine:RINoise:TYPe command to configure the measurement to be based on the one level or based on Optical Modulation Amplitude (OMA) measurement.

Use the :MEASure:AMPLitude:DEFine:RINoise:UNITs command, if the input channel has an optical reference filter, to normalize the RIN value to the equivalent noise bandwidth of the sampling channel.

Use the :MEASure:AMPLitude:DEFine:RINoise:DEFinition command select if the results are based either on FlexDCA's Legacy algorithm or the IEEE 802.3. Click here for the RIN equations. The result of the IEEE based measurement is approximately 6 dB greater than FlexDCA's legacy measurement. Legacy is the default selection.

This measurement can be made on PAM4 waveforms. See the sidebar in this topic. The measurement results are moved to the top of the Level table.

You can perform a RIN measurement on an optical signal that is input to an electrical channel by using an external O/E transducer. For this to work, you must setup the transducer with these steps. The RIN measurement will then be available and, if desired, you can also perform a dark calibration on the electrical channel.

To configure an external transducer

  1. Click the External HW button in the electrical channel's Channel setup dialog.
  2. In the Channel External Hardware Setup dialog, select An External Transducer is Connected.
  3. Click Setup.
  4. In the Transducer Conversion Factors dialog, select WATT for the units. Enter the transduce's gain and offset.

To configure an external transducer with SCPI commands

  1. Use the :CHANnel:TRANsducer:STATe command to specify that an external transducer is connected.
  2. Use the :CHANnel:TRANsducer:UNITs command to select WATT as the measurement units.
  3. Use the :CHANnel:TRANsducer:GAIN and :CHANnel:TRANsducer:OFFSet commands to specify the transduce's gain and offset.

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:AMPLitude:RINoise:

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

Child commands for measurement identification:

  • :MEASure:AMPLitude:RINoise:SOURce

Amplitude analysis must be turned on before the first interference measurement can be made. Use the :MEASure:AMPLitude:DEFine:ANALysis command.

Example Command Sequence

:MEASure:AMPLitude:DEFine:ANALysis ON
:MEASure:AMPLitude:RINoise:SOURce CHAN2A
:MEASure:AMPLitude:DEFine:RINoise:TYPe OMA
:MEASure:AMPLitude:DEFine:RINoise:UNITs DECibel
:MEASure:AMPLitude:RINoise
:MEASure:AMPLitude:RINoise?

Measurement Ready?

To confirm that the measurement is ready to read, you can query the measurement's status:

if ('CORR' in Flex.query(':MEASure:AMPLitude:RINoise:STATus?')):
	measurement = Flex.query(':MEASure:AMPLitude:RINoise?')

If averaging is turned on (:ACQuire:AVERaging), you can also confirm if the measurement result is ready by comparing the number of specified averages (:ACQuire:ECOunt?) versus the number of measurement sweeps that have occurred (:MEASure:AMPLitude:RINoise:COUNt?). The technique uses the :COUNt? common measurement query. For example,

if (Flex.query(':MEASure:AMPLitude:RINoise:COUNt?') >= Flex.query(':ACQuire:ECOUNt?')):
	measurement = Flex.query(':MEASure:AMPLitude:RINoise?')

You can also use an acquisition limit lest to test that a number of waveform samples, or pattern acquisitions have completed before returning a measurement. Refer to the :LTESt:ACQuire:CTYPe command.

Common Measurement Child Queries

This command supports the use of the following common measurement queries: :LOCation?, :COUNt?, :MAXimum?, :MINimum?, :MEAN?, and :SDEViation?.