Agilent Technologies Infiniium 90000 Q-Series, Programmer'S Manual

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520 Agilent Infiniium 90000 Series Oscilloscopes Programmer's Reference
25
Measure Commands
:MEASure:DEEMphasis
Command
:MEASure:DEEMphasis [<source>]
When the EZJIT Complete application is licensed, the Deemphasis serial
data measurement becomes available.
The :MEASure:DEEMphasis command adds the deemphasis measurement.
The de- emphasis measurement relies on the clock recovery to recover a
clock for each bit in the data waveform. You need to configure clock
recovery appropriately for your signal.
Sources are specified with the :MEASure:SOURce command or with the
optional parameter following the :MEASure:DEEMphasis command.
<source>
{CHANnel<N> | FUNCtion<F> | WMEMory<N> | CLOCk | MTRend |
MSPectrum | EQUalized}
MTRend and MSPectrum sources are only available if the oscilloscope has
the EZJIT option installed and the feature is enabled.
The CLOCk source is only available if the oscilloscope has the High Speed
Serial option installed and the feature is enabled.
The EQUalized source is only available if the oscilloscope has the High
Speed Serial option and the Serial Data Equalization option installed and
the features are enabled. This command uses the Feed- Forward Equalized
(FFE) signal as the source.
<N>
CHANnel<N> is an integer, 1- 4.
WMEMory<N> is an integer, 1- 4.
<F>
FUNCtion<F> is an integer, 1- 16.
Example This example adds the deemphasis measurement on the channel 1 source.
myScope.WriteString ":MEASure:DEEMphasis CHANnel1"
Query
:MEASure:DEEMphasis? [<source>]
The :MEASure:DEEMphasis? query returns the measured deemphasis value
of the specified source.
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. See
":MEASure:STATistics" on page 643.
Returned Format
[:MEASure:DEEMphasis] <value>[,<result_state>]<NL>
<value>
For every de- emphasis bit in the waveform, a value is computed using:
20 * log
10
(de- emphasis voltage / transition voltage)