:MEASure:EYE:APOWer
Command Syntax
:MEASure:EYE:APOWer
Query Syntax
:MEASure:EYE:APOWer?
Description
Moves the Average Power measurement to the top of the Results table. Displays the measurement if it is not already shown on the table. The query form of the command returns the measured value. Average Power is the true average component of an optical signal. A waveform annotation label is placed on the average power result. Since the average power is calculated over the entire display graticule, this label tracks the average power result across the graticule. This measurement is commonly used when identifying the fundamental parameters of a lightwave transmitter. However, it differs from other measurements because it does not rely on the waveform display in order to determine the measurement. You can measure the average power of an eye diagram. Average power is a measure of the true average component of an optical signal.
The average power measurement is only available when using the modules with integrated optical detectors (optical/electrical modules). Average power measurements cannot be made on simulated channels.
This Eye mode measurement can be applied to NRZ waveforms but not PAM4 waveforms.
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:APOWer:
flex.write(':MEASure:EYE:APOWer:SOURce CHAN1A')
if flex.query(':MEASure:EYE:APOWer:STATus?') == 'CORR';
measurement = flex.query(':MEASure:EYE:APOWer?')
else:
details = flex.query(':MEASure:EYE:APOWer:STATus:DETails?')
reason = flex.query(':MEASure:EYE:APOWer:STATus:REASon?')
Child commands for measurement identification:
:MEASure:EYE:APOWer:SOURce:MEASure:EYE:APOWer:UNITs
Example Command Sequence
:MEASure:EYE:APOWer:SOURce CHAN2B :MEASure:EYE:APOWer:UNITs :MEASure:EYE:APOWer :MEASure:EYE:APOWer?
Measurement Ready?
To confirm that the measurement is ready to read, you can query the measurement's status:
if ('CORR' in Flex.query(':MEASure:EYE:APOWer:STATus?')):
measurement = Flex.query(':MEASure:EYE:APOWer?')
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:EYE:APOWer:COUNt?). The technique uses the :COUNt? common measurement query. For example,
if (Flex.query(':MEASure:EYE:APOWer:COUNt?') >= Flex.query(':ACQuire:ECOUNt?')):
measurement = Flex.query(':MEASure:EYE:APOWer?')
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?.