# :FUNCtion:SNDRatio:STANdard

:FUNCtion SNDR Setup Commands

- :FUNCtion:SNDRatio:FILE:NAME
- :FUNCtion:SNDRatio:FILE:RELoad
- :FUNCtion:SNDRatio:LFPDelay
- :FUNCtion:SNDRatio:LFPLength
- :FUNCtion:SNDRatio:NAVerages
- :FUNCtion:SNDRatio:PUINterval
- :FUNCtion:SNDRatio:RLMStandard
- :FUNCtion:SNDRatio:RNComp
- :FUNCtion:SNDRatio:RNCValue:LEVel
- :FUNCtion:SNDRatio:SAVE
- :FUNCtion:SNDRatio:SAVE:FILE
- :FUNCtion:SNDRatio:STANdard

## Command Syntax

    :FUNCtionN:SNDRatio:STANdard {ASA13 | AUTomatic | PCIe | IDJ | IEEe | ASA45 | USB4 | FILE}

Where N identifies one of sixty four {1:64} math functions that you can create. For example, `:FUNCtion2`.

## Query Syntax

    :FUNCtionN:SNDRatio:STANdard?

## Description

Select the technology standard you want to use for SNDR measurement definitions:

SNDR Standards
Signal Type | Standard | Notes
--- | --- | ---
NRZ | ASA13 | ASA SG1-3 (Speed Grade SG1, SG2, or SG3) — This selection uses the technique outlined in the ASA (Automotive SerDes Alliance) Transceiver specification version 1.1 section 4.4.1.1.2.
NRZ, PAM3, PAM4 | AUTomatic | Based on the input pattern, the algorithm looks for ideal points that can be used to calculate Sigma-n. Any pattern that contains every signal level is supported. Then, the Sigma-e and Pmax measurements are calculated using the same method as IEEe (without requiring the PRBS13Q pattern).
PAM4 | PCIe | PCIe 6.0 — This selection, available with PAM4 signal types, uses a process described in the PCIe 6.0 standard.
PAM4 | IDJ | IEEE 802.3 dj — This is the same as the IEEe option except it uses PCIe Sum of Squares of LFPR for "Pmax" instead of just maximum.
PAM4 | IEEe | IEEE (PRBS13Q) — This selection uses the technique outlined in the IEEE 802.3 specification clause 120D.3.1.6. The algorithm looks for six or more consecutive identical symbols and places the voltage measurement at the center of the 3rd UI. The variance of all those measurements is taken and then the standard deviations are averaged to get σn. The PRBS13Q pattern provides runs of at least six consecutive identical PAM4 symbols at each of the PAM4 levels.
PAM4 | ASA45 | ASA SG4, 5 (Speed Grade SG4 or SG5) — This selection uses the technique outlined in the ASA (Automotive SerDes Alliance) Transceiver specification version 1.1 section 4.4.1.1.2.
PAM3 | USB4 | This selection uses the technique outlined in the USB4 specification version 2.0 section 3.2.3.4.
NRZ, PAM3, PAM4 | FILE | This selection allows for custom measurement parameters loaded from a file. The format of this file is proprietary. For help developing custom files, contact Keysight Technical Support and ask for an Application Engineer.

The options available depend on the signal type selection (see `:FUNCtion:SIGNal:TYPE`).

When `FILE` is selected as the SNDR standard, use the `:FUNCtion:SNDRatio:FILE:NAME` command to specify the name of the SNDR standard definition file, and use the `:FUNCtion:SNDRatio:FILE:RELoad` command to reload the SNDR standard definition file, for example, after loading a setup file.