:MEASure:AMPLitude:DEPCie

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

Command Syntax

:MEASure:AMPLitude:DEPCie

Query Syntax

:MEASure:AMPLitude:DEPCie?

Description

Moves the De-emphasis (PCIe) measurement 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. PCIe is a deliberatly introduced distortion on the preceding edge of a waveform transition. De-emphasis is often used to counter the effects of reduced transmission bandwidth, which tend to close eye-diagrams. This de-emphasis measurement is based on the PCI Express Gen 3 definition.

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:DEPCie:

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

Child commands for measurement identification:

  • :MEASure:AMPLitude:DEPCie: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:DEPCie:SOURce CHAN1A
:MEASure:AMPLitude:DEPCie
:MEASure:AMPLitude:DEPCie?

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:DEPCie:STATus?')):
	measurement = Flex.query(':MEASure:AMPLitude:DEPCie?')

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:DEPCie:COUNt?). The technique uses the :COUNt? common measurement query. For example,

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

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?.