:MEASure:DATA:DEEMphasis

Deemphasis Commands

Command Syntax

:MEASure:DATA:DEEMphasis

Query Syntax

:MEASure:DATA:DEEMphasis?

Description

This command moves the Deemphasis measurement to the top of the Results table and displays the measurement if it is not already shown on the table.

The query form of the command returns the measured value.

To measure Deemphasis, :CRECovery:MODE must be performed to recover a clock for each bit in the data waveform.

For every Deemphasis bit in the waveform, a value is computed using:

20 * log10(deemphasis voltage / transition voltage)

Where:

  • Transition voltage is the voltage at the clock location of the preceding transition bit.
  • Deemphasis voltage is the voltage at the clock location of deemphasis bits following a transition bit.

Due to random noise, many bits need to be averaged together to average out the noise. Therefore, the current value has little importance and the mean should be used.

Use :MEASure:DATA:DEEMphasis:REGion to specify the waveform data region over which the measurement is made.

Sources can be any displayed waveform, waveform memory, or function. For example, CHAN1_1, WMEMory1, or FUNCtion1.

Use :MEASure:TBASe:GENeral:METHod to change the definition of the waveform's top/base. Use :<waveform>:THReshold:GENeral:METHod to change the definition of the waveform's threshold.

Example Command Sequence

:MEASure:DATA:DEEMphasis:SOURce CHAN1_1
:MEASure:DATA:DEEMphasis:REGion DISPlay
:MEASure:DATA:DEEMphasis
:MEASure:DATA:DEEMphasis?

Measurement Ready?

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

if ('CORR' in Infiniium.query(':MEASure:DATA:DEEMphasis:STATus?')):
	measurement = Infiniium.query(':MEASure:DATA:DEEMphasis?')

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

if (Infiniium.query(':MEASure:DATA:DEEMphasis:COUNt?') >= Infiniium.query(':ACQuire:COUNt?')):
	measurement = Infiniium.query(':MEASure:DATA:DEEMphasis?')

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

Querying Measurement Results and Statistics

You can query measurement results using the :MEASure:DATA:DEEMphasis? query after making the proper instance settings.

If a measurement is installed into Results table (using the :MEASure:DATA:DEEMphasis command) and you have made the proper instance settings, you can query statistics using common child queries.

Also, you can query measurement results and statistics directly from the Results table (without having to make the proper instance settings beforehand). See Querying Measurement Results and Statistics.