PicoVNA-106-MATLAB-Library/README.md

PicoVNA106 — MATLAB Instrument Driver

A MATLAB class for controlling the PicoVNA 106 vector network analyzer over a TCP/IP connection. Provides methods for triggering sweeps, acquiring S-parameters in polar form, querying frequency axes, and packaging results into an SPARAMS object.

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Requirements

• MATLAB with the Instrument Control Toolbox
• The PicoVNA software must be running on the host machine with its SCPI server active on localhost:5025
• The companion SPARAMS class (required by readToSparamsObject, available at https://github.com/njchorda/MATLAB-Touchstone-Reader)

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Installation

1. Clone or download this repository.
2. Add the folder to your MATLAB path:

   addpath('/path/to/PicoVNA106');
   

3. Ensure the PicoVNA application is open and its SCPI server is enabled before instantiating the class.

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Quick Start

% Connect to the VNA
vna = PicoVNA106();

% Trigger a single sweep and wait for completion
vna.sweep();

% Read all four S-parameters as complex polar data
[S11, S12, S21, S22] = vna.getSParams();

% Get the corresponding frequency axis in Hz
f = vna.getFreqAxis();

% Or read everything into a single SPARAMS object
S = vna.readToSparamsObject();

% Clean up
vna.deInit();

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API Reference

Constructor

obj = PicoVNA106()

Opens a TCP connection to localhost:5025 with a default timeout of 10 seconds. The PicoVNA 5 software must already be running.

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Sweep Control

vna.sweep()

Triggers a single sweep (INIT) and waits for the instrument to acknowledge completion.

vna.setContinuousSweep()

Puts the instrument into continuous sweep mode (INIT:CONT:ALL).

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S-Parameter Acquisition

[S11, S12, S21, S22] = vna.getSParams()

Reads all four S-parameters from the instrument buffer as complex polar vectors. Each value is returned as a column vector of complex doubles. Does not trigger a new sweep — call sweep() first if fresh data is needed.

S = vna.readToSparamsObject()

Combines getSParams() and getFreqAxis() into a single SPARAMS object. Sets the reference impedance to 50 Ω and the port count to 2. The S-parameter and frequency vectors are column-oriented.

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Frequency Axis

f = vna.getFreqAxis()

Queries the start frequency, stop frequency, and number of sweep points from the instrument and returns a linearly spaced frequency vector in Hz. Handles kHz, MHz, and GHz unit strings automatically.

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Power Level

p = vna.getPowerLevel()

Returns the current stimulus power level in dBm.

vna.setPowerLevel(p)

Sets the stimulus power level in dBm.

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Instrument Utilities

id = vna.getID()

Queries the instrument identification string (*IDN?).

vna.reset()

Sends *RST to reset the instrument to its default state.

vna.selfTest()

Runs the built-in self-test (*TST?) and prints the result to the console.

vna.setLocal()

Returns front-panel control to the user (SYST:LOC).

vna.clearBuffer()

Flushes any pending data in the TCP receive buffer by reading until empty. Temporarily reduces the timeout to 0.2 s during the flush.

retVal = vna.sendCommand(cmd)

Sends an arbitrary SCPI command. If the command contains ?, it reads and returns the response string; otherwise returns 0.

vna.deInit()

Releases the TCP connection. Returns 1 on success, 0 if the connection was already invalid.

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Notes

• S-parameters are returned in polar (real/imaginary) format — the instrument sends interleaved real and imaginary doubles which the driver recombines into complex MATLAB arrays.
• getSParams() does not trigger a sweep. Always call sweep() before reading data if you need up-to-date measurements.
• The frequency string parser handles kHz, MHz, and GHz unit suffixes from the instrument response. Responses in plain Hz are not currently handled — extend freqStrConvert if needed.
• The default TCP timeout is 10 seconds, which may need increasing for slow sweeps (e.g. high point counts or narrow IF bandwidths).

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License

MIT License — see LICENSE for details.