Table of Contents

• Table of Contents
• About
  • Documentation
  • Operating System Support
• Installation
• License
• Support and Feedback
• Example

About

The nirfmx-python repository generates Python bindings (Application Programming Interface) for interacting with the RFmx Products.

nirfmx-python follows Python Software Foundation support policy for different versions.

RFmx Instr Python API Status

RFmx SpecAn Python API Status

Documentation

You can find the latest API documentation for the nirfmx-python package on Read the Docs

Refer to the RFmx User Manual for an overview of RFmx, system requirements, troubleshooting, key concepts, etc.

Operating System Support

nirfmx-python supports Windows systems where the supported drivers are installed. Refer to NI Hardware and Operating System Compatibility for which versions of the driver support your hardware on a given operating system.

Installation

You can use pip to download nirfmxspecan and install it.

$ python -m pip install nirfmxspecan

To also install gRPC support for remote NI gRPC Device Server communication:

$ python -m pip install "nirfmxspecan[grpc]"

Upgrade

You can use pip to upgrade nirfmxspecan package using following command:

$ python -m pip install nirfmxspecan --upgrade

License

This project is licensed under the MIT License. While the source code is not publicly released, the license permits binary distribution with attribution.

Note: This Python driver depends on several third-party components that are subject to separate commercial licenses. Users are responsible for ensuring they have the appropriate rights and licenses to use those dependencies in their environments.

gRPC Features

For driver APIs that support it, passing a GrpcSessionOptions instance as a parameter to nirfmxinstr.Session.init() is subject to the NI General Purpose EULA.

SSL/TLS Support

The server supports both server-side TLS and mutual TLS. Security configuration is accomplished by setting the server_cert, server_key and root_cert values in the server's configuration file. The server expects the certificate files specified in the configuration file to exist in a certs folder that is located in the same directory as the configuration file being used by the server. For more detailed information on SSL/TLS support refer to the Server Security Support wiki page.

Support and Feedback

For support with Python API, hardware, the driver runtime or any other questions, please visit NI Community Forums.

RFmxSpecAn Example

import nirfmxinstr
import nirfmxspecan
import numpy

instr_session = None
specan = None

try:
    # Open a RFmx Session
    instr_session = nirfmxinstr.Session(resource_name="RFSA", option_string="")

    # Configure RFmx Session
    instr_session.configure_frequency_reference(
        selector_string="",
        frequency_reference_source="OnboardClock", 
        frequency_reference_frequency=10.0e+6
    )

    # Create SpecAn Signal
    specan = instr_session.get_specan_signal_configuration()

    # Configure SpecAn Signal
    specan.set_selected_ports(selector_string="", value="")
    specan.configure_frequency(selector_string="", center_frequency=1e+9)
    specan.configure_reference_level(selector_string="", reference_level=0.0)
    specan.configure_external_attenuation(selector_string="", external_attenuation=0.0)

    # Select Spectrum Measurement
    specan.select_measurements(
        selector_string="",
        measurements=nirfmxspecan.MeasurementTypes.SPECTRUM, 
        enable_all_traces=True
    )

    # Configure Spectrum Measurement
    specan.spectrum.configuration.configure_span(selector_string="", span=1.0e+6)
    specan.spectrum.configuration.configure_measurement_method(
        selector_string="",
        measurement_method=nirfmxspecan.SpectrumMeasurementMethod.NORMAL
    )

    error_code = specan.initiate(selector_string="", result_name="")

    # Retrieve Results
    # The numpy arrays are passed in pre-allocated. If the pre allocated array size does not match the
    # actual array size returned by the measurement, the array is automatically resized to fit the data,
    # which may invalidate the previously created view. Passing an empty array (size 0) is fine;
    # it will be resized as needed.
    spectrum = numpy.empty(0, dtype=numpy.float32)
    x0, dx, _ = specan.spectrum.results.fetch_spectrum(
        selector_string="", 
        timeout=10.0,
        spectrum=spectrum
    )
    peak_amplitude, peak_frequency, frequency_resolution, error_code = (
        specan.spectrum.results.fetch_measurement(selector_string="", timeout=10.0)
    )

    # Print Results
    print(f"Peak Amplitude (dBm)             {peak_amplitude}")
    print(f"Peak Frequency (Hz)              {peak_frequency}")

except Exception as e:
    print("ERROR: " + str(e))

finally:
    # Dispose Signal & Session
    if specan is not None:
        specan.dispose()
        specan = None
    if instr_session is not None:
        instr_session.close()
        instr_session = None

Numpy array size handling in RFmx APIs

The numpy arrays are passed in pre-allocated. If the pre allocated array size does not match the actual array size returned by the measurement, the array is automatically resized to fit the data, which may invalidate the previously created view. Passing an empty array (size 0) is fine; it will be resized as needed.