DOCSIS Fast Detection Macro (DOCSIS 4.0 Downstream )

(Only applies to DOCSIS 4.0 Downstream modulation analysis)

The DOCSIS Fast Detection macro (DocsisFastDetection) saves existing Center Frequency, Span, and Search Length settings, adjust settings for optimal PLC detection, capture and decode the signal’s PLC information, restore the saved settings, and restart the measurement using the correct PLC information. The macro progress is reported in the Output window.

The Docsis Fast Detection macro can be found in the following location:

%PROGRAMFILES%\Keysight\89600 Software <ReleaseVersion>\89600 VSA Software\Examples\Macros\DocsisFastDetection

The macro relies on a valid measurement configuration being specified. Make sure that the following measurement configuration parameters are correct before attempting to run this macro:

• General settings:

  • Center Frequency

  • Span

  • Demodulator (set to DOCSIS 4.0 Downstream)

• DOCSIS 4.0 Downstream Demodulation parameters:

  • Search Length

  • Search Length Auto
  • Result Length
  • Measurement Interval

To use the Preamble Index detection macro, perform the following procedure sequence:

1. Launch the VSA software.
2. Set up the DOCSIS 4.0 Upstream input signal.
3. Select the DOCSIS 4.0 Upstream measurement type.
4. Open the DOCSIS 4.0 Upstream Demod Properties dialog.
5. Open the Output window (Window > Output) to view macro status messages.
6. Open the Macros dialog (Utilities > Macros…).
7. If first time, Import the DocsisFastDetection macro (Import… > %PROGRAMFILES%\Keysight\89600 Software <ReleaseVersion>\89600 VSA Software\Examples\Macros\DocsisFastDetection).
8. Select DocsisFastDetection and click (Build and) Run.
9. In the PLC Detection dialog, click Detect.
10. The DocsisFastDetection macro will save existing Center Frequency, Span, and Search Length settings, adjust settings for optimal PLC detection, capture and decode the signal’s PLC information, restore the saved settings, and restart the measurement using the correct PLC information.
11. If the PLC Detection dialog’s Detection Information field reports “Basic settings not detected” or “PLC information not detected," the macro is aborted.
12. Click Exit in the PLC Detection dialog to close the macro (not the Stop button in the Macros dialog).