EXTRACT_SPECTRUM_RSA500

Extracts and returns the spectrum trace from an Tektronix RSA. This block should also work with compatible Tektronix RSAXXX instruments. Tested with RSA507a. Params: center_freq : float, default=100e6 The center frequency, in Hz. ref_level : float, default=-30 The reference level (the maximum y axis value), in dBm. span : float, default=1e6 The width of the x axis, in Hz. bandwidth : float, default=10e3 Resolution bandwidth, in Hz. Returns: out : OrderedPair RF spectrum trace

Python Code

from flojoy import flojoy, DataContainer, OrderedPair
from typing import Optional, Literal
from flojoy.instruments.tektronix.RSA_API import *  # noqa: F403
from ctypes import cdll, c_int, c_bool, c_double, c_float
from os import path
import numpy as np


@flojoy()
def EXTRACT_SPECTRUM_RSA500(
    input: Optional[DataContainer] = None,
    center_freq: float = 100e6,
    ref_level: float = -30,
    span: float = 1e6,
    bandwidth: float = 10e3,
) -> OrderedPair:
    """Extracts and returns the spectrum trace from an Tektronix RSA.

    This block should also work with compatible Tektronix RSAXXX instruments.

    Tested with RSA507a.

    Parameters
    ----------
    center_freq : float, default=100e6
        The center frequency, in Hz.
    ref_level : float, default=-30
        The reference level (the maximum y axis value), in dBm.
    span : float, default=1e6
        The width of the x axis, in Hz.
    bandwidth : float, default=10e3
        Resolution bandwidth, in Hz.

    Returns
    -------
    OrderedPair
        RF spectrum trace
    """

    # Connect to RSA
    moved = "C:/Program Files/Tek/RSA_API/lib/x64/RSA_API.dll"
    defau = "C:/Tektronix/RSA_API/lib/x64/RSA_API.dll"
    if path.isfile(defau):
        rsa = cdll.LoadLibrary(defau)
    elif path.isfile(moved):
        rsa = cdll.LoadLibrary(moved)
    else:
        raise FileNotFoundError(
            "Cannot find RSA_API.dll. Download from: https://www.tek.com/en/products/spectrum-analyzers/rsa500"
        )

    numFound = c_int(0)
    intArray = c_int * DEVSRCH_MAX_NUM_DEVICES
    deviceIDs = intArray()
    deviceSerial = create_string_buffer(DEVSRCH_SERIAL_MAX_STRLEN)
    deviceType = create_string_buffer(DEVSRCH_TYPE_MAX_STRLEN)
    apiVersion = create_string_buffer(DEVINFO_MAX_STRLEN)

    rsa.DEVICE_GetAPIVersion(apiVersion)

    err_check(rsa.DEVICE_Search(byref(numFound), deviceIDs, deviceSerial, deviceType))

    # note: the API can only currently access one at a time
    # Connects to first available
    err_check(rsa.DEVICE_Connect(deviceIDs[0]))
    rsa.CONFIG_Preset()

    # Configure spectrum
    cf = center_freq
    refLevel = ref_level
    rbw = bandwidth

    rsa.SPECTRUM_SetEnable(c_bool(True))
    rsa.CONFIG_SetCenterFreq(c_double(cf))
    rsa.CONFIG_SetReferenceLevel(c_double(refLevel))

    rsa.SPECTRUM_SetDefault()
    specSet = Spectrum_Settings()
    rsa.SPECTRUM_GetSettings(byref(specSet))
    specSet.window = SpectrumWindows.SpectrumWindow_Kaiser
    specSet.verticalUnit = SpectrumVerticalUnits.SpectrumVerticalUnit_dBm
    specSet.span = span
    specSet.rbw = rbw
    rsa.SPECTRUM_SetSettings(specSet)
    rsa.SPECTRUM_GetSettings(byref(specSet))

    ready = c_bool(False)
    traceArray = c_float * specSet.traceLength
    traceData = traceArray()
    outTracePoints = c_int(0)
    traceSelector = SpectrumTraces.SpectrumTrace1

    # Retrieve spectrum
    rsa.DEVICE_Run()
    rsa.SPECTRUM_AcquireTrace()
    while not ready.value:
        rsa.SPECTRUM_WaitForDataReady(c_int(100), byref(ready))
    rsa.SPECTRUM_GetTrace(
        traceSelector, specSet.traceLength, byref(traceData), byref(outTracePoints)
    )
    rsa.DEVICE_Stop()
    trace = np.array(traceData)

    freq = np.arange(
        specSet.actualStartFreq,
        specSet.actualStartFreq + specSet.actualFreqStepSize * specSet.traceLength,
        specSet.actualFreqStepSize,
    )

    rsa.DEVICE_Disconnect()

    return OrderedPair(x=freq, y=trace)


def err_check(rs):
    if ReturnStatus(rs) != ReturnStatus.noError:
        raise RSAError(ReturnStatus(rs).name)

Find this Flojoy Block on GitHub

Example

Having problems with this example app? Join our Discord community and we will help you out!

Press enter or space to select a node.You can then use the arrow keys to move the node around. Press delete to remove it and escape to cancel.

Press enter or space to select an edge. You can then press delete to remove it or escape to cancel.

Download this Flojoy App

In this example, Flojoy was used to extract an RF spectrum from a Tektronix RSA500.

First the necessary blocks were added:

• EXTRACT_SPECTRUM_RSA500
• LINE

The default parameters are set to the FM radio frequencies (100 MHz). Set center_freq to your favourite station and see the resulting spectrum.