RFmx VNA Python API Documentation

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.

Operating System Support

nirfmxvna 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 nirfmxvna and install it.

$ python -m pip install nirfmxvna

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

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

Upgrade

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

$ python -m pip install nirfmxvna --upgrade

Support and Feedback

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

Documentation:

• Attributes
• Enums
• Errors
• gRPC Support
• IntegratedPower
• IntegratedPowerConfiguration
• IntegratedPowerResults
• IQ
• IQConfiguration
• IQResults
• Marker
• MarkerConfiguration
• MarkerResults
• SParams
• SParamsConfiguration
• SParamsResults
• VNA
• Waves
• WavesConfiguration
• WavesResults

Example:

import nirfmxinstr
import nirfmxvna
import numpy

instr_session = None
vna_signal = None

try:
  # Create a new RFmx Session
  instr_session = nirfmxinstr.Session(resource_name="VNA", option_string="")

  # Get VNA signal configuration
  vna_signal = instr_session.get_vna_signal_configuration()

  instr_session.configure_frequency_reference(
    selector_string="",
    frequency_reference_source="OnboardClock",
    frequency_reference_frequency=10e6
  )

  vna_signal.set_sweep_type(selector_string="", value=nirfmxvna.SweepType.LINEAR)
  vna_signal.set_start_frequency(selector_string="", value=1e9)
  vna_signal.set_stop_frequency(selector_string="", value=2e9)
  vna_signal.set_number_of_points(selector_string="", value=101)
  vna_signal.set_if_bandwidth(selector_string="", value=10e3)

  port_selector_string = nirfmxvna.Vna.build_port_string(selector_string="", port_string="port1")
  vna_signal.set_power_level(selector_string=port_selector_string, value=-10.0)
  vna_signal.set_test_receiver_attenuation(
    selector_string=port_selector_string,
    value=0.0
  )

  port_selector_string = nirfmxvna.Vna.build_port_string(selector_string="", port_string="port2")
  vna_signal.set_power_level(selector_string=port_selector_string, value=-10.0)
  vna_signal.set_test_receiver_attenuation(
    selector_string=port_selector_string,
    value=0.0
  )

  vna_signal.set_averaging_enabled(
    selector_string="",
    value=nirfmxvna.AveragingEnabled.FALSE
  )
  vna_signal.set_averaging_count(selector_string="", value=10)

  vna_signal.select_measurements(
    selector_string="",
    measurements=nirfmxvna.MeasurementTypes.WAVES,
    enable_all_traces=True
  )

  vna_signal.waves.configuration.set_number_of_waves(selector_string="", value=2)

  for i in range(2):
    wave_selector_string = nirfmxvna.Vna.build_wave_string(selector_string="", wave_index=i)
    vna_signal.waves.configuration.configure_wave(
      selector_string=wave_selector_string,
      receiver=nirfmxvna.WavesReceiver.TEST,
      source_port="port1",
      measurement_port="port1"
    )
    vna_signal.waves.configuration.set_format(
      selector_string=wave_selector_string,
      value=nirfmxvna.WavesFormat.MAGNITUDE
    )

  vna_signal.waves.configuration.set_magnitude_units(
    selector_string="",
    value=nirfmxvna.WavesMagnitudeUnits.DBM
  )
  vna_signal.waves.configuration.set_phase_trace_type(
    selector_string="",
    value=nirfmxvna.WavesPhaseTraceType.WRAPPED
  )

  vna_signal.initiate(selector_string="", result_name="")

  # Retrieve results
  number_of_waves_result, error_code = vna_signal.waves.configuration.get_number_of_waves(
    selector_string=""
  )

  # 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.
  waves_x_data_result = numpy.empty(0, dtype=numpy.float64)
  waves_x_data_result = vna_signal.waves.results.fetch_x_data(
    selector_string="",
    timeout=10.0
  )

  waves_y1_data_result = []
  waves_y2_data_result = []

  for i in range(number_of_waves_result):
    wave_selector_string = nirfmxvna.Vna.build_wave_string(selector_string="", wave_index=i)

    y1_data, y2_data, error_code = vna_signal.waves.results.fetch_y_data(
      selector_string=wave_selector_string,
      timeout=10.0
    )

    waves_y1_data_result.append(y1_data)
    waves_y2_data_result.append(y2_data)

except Exception as e:
  print(f"Error occurred: {e}")
  sys.exit(1)

finally:
  if vna_signal is not None:
    vna_signal.dispose()
    vna_signal = 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.

Additional Documentation

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

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](https://github.com/ni/grpc-device/wiki/Server-Security-Support).

Indices and Tables

• Index

• Module Index