:SPRocess:FFEQualizer:TAPS:AUTo

Instrument:
N1000A
N109x
Flex Apps:
FlexDCA
FlexRT
Meas. mode:
Scope
Eye
Jitter
TDR
Package License:
L-RND

To Install FFE Operator

Use this command:

:FUNCtion:FOPerator FFEQualizer

If secondary to Reference Rx operator:

:FUNCtion:SOP3 FFEQualizer

Linear Equalizer Commands

Command Syntax

:SPRocessN:FFEQualizer:TAPS:AUTo {OFF | ON}

Where N identifies one of up to 64 possible operators {1:64} that can be defined as part of a math function. The operators are numbered in the order that they were originally added to the function.

Query Syntax

:SPRocessN:FFEQualizer:TAPS:AUTo?

Description

Turns on and off automatic configuration of taps for a Linear Equalizer operator (LFE). By default, automatic configuration is on.

OFF
Disables automatic tap configuration to enable manual entry of tap values. Use the :SPRocess:FFEQualizer:TAPS command to enter the individual tap values. Use the :SPRocess:FFEQualizer:TAPS:NORMalize command to automatically adjust the tap values for a maximum equalizer gain of 0 dB (unity). The relative contributions of the tap values are maintained. Use the :SPRocess:FFEQualizer:TSPacing command to select tap spacing based on taps-per-bit or seconds.
ON
Enables automatic tap configuration. Use the :SPRocess:FFEQualizer:NPRecursors command to specify the precursors used for automatic configuration. To enter the number of taps, use the :SPRocess:FFEQualizer:TAPS:COUNt command. Automatic tap configuration sets the optimum tap values to open an eye diagram, but requires that you use a PRBS pattern that has a length that is listed in the following table. Inverted PRBS patterns are also supported. The table also lists the generating polynomials. Use the :SPRocess:FFEQualizer:TSPacing:TPBit command to enter the tap spacing in number of taps-per-bit. You cannot specify a tap spacing based on time in automatic tap configuration mode. Use the :SPRocess:FFEQualizer:TAPS:RECalculate command to automatically recalculate the tap values.
PRBS Patterns for Optimum Tap Values
PRBS Polynomial PRBS Polynomial
25−1 x5+x4+x2+x1+1 211−1 x11+x9+1
26−1 x6+x5+x3+x2+1 212−1 x12+x9+x8+x5+1
27−1 x7+x6+1 213−1 x13+x12+x10+x9+1
28−1 x8+x7+x3+x2+1 214−1 x14+x13+x10+x9+1
29−1 x9+x5+1 215−1 x15+x14+1
210−1 x10+x7+1

For Reference Rx operator, what function do I send this command to?

If the FFE (Linear Equalizer) equalizer is a secondary function to the Reference Rx operator, address the :SPRocess:FFEQualizer:TAPS:AUTo command to the Reference Rx function as identified in the following Reference Rx Setup dialog's operator diagram. In the following figure, this would be Function 2 and the command would be:

:SPRocess2:FFEQualizer:TAPS:AUTo

Beginning with FlexDCA revision A.05.60, use of an *OPC? query to pause program execution while waiting for this command to execute.

The Linear Feedforward Equalizer operator is provided with the N1010A-201 Advanced Waveform Analysis license.

Example Command Sequence

:FUNCtion2:FOPerator FFEQualizer
:SPRocess2:FFEQualizer:TAPS:AUTo ON;*OPC?
:SPRocess2:FFEQualizer:TAPS:COUNt 5;*OPC?
:SPRocess2:FFEQualizer:NPRecursors 3
:SPRocess2:FFEQualizer:TSPacing:TPBit 2
:SPRocess2:FFEQualizer:BANDwidth:AUTo OFF
:SPRocess2:FFEQualizer:BANDwidth 8.0E9
:FUNCtion2:COLor TCOLor4
:FUNCtion2:DISPlay ON
*OPC?
…  //  Your code to synchronize execution timing.