class pyrf.devices.thinkrf.WSA(connector=None)

Interface for ThinkRF’s R5500, R5700, and WSA5000 (EOL).

Parameters:connector – Connector object to use for SCPI/VRT connections, defaults to a new PlainSocketConnector instance

connect() must be called before other methods are used.


The following methods will either block then return a result or if you passed a TwistedConnector instance to the constructor, they will immediately return a Twisted Deferred object.

The methods are grouped and listed by functionalities.

Connection Related Methods:


Connect to an RTSA (aka WSA).

Parameters:host (str) – the hostname or IP to connect to



Close a connection to an RTSA (aka WSA).


Return True if the connector being used is asynchronous


Set the asynchronous callback for a function when the device receives a VRT packet. Use with Twisted setup. :param callback: callback to set. Set to None to disable receiving packets.

Direct SCPI commands:


Send a SCPI query command and wait for the response.

This is the lowest-level interface provided. See the product’s Programmer’s Guide for the SCPI commands available.

Parameters:cmd (str) – the SCPI command to send
Returns:the response output from the box if any

Send a SCPI command of set type (i.e. not query command).

This is the lowest-level interface provided. See the product’s Programmer’s Guide for the SCPI commands available.

Parameters:cmd (str) – the command to send

Flush and return the list of errors from past commands sent to the RTSA. An empty list is returned when no errors are present.

Device System Related:


Returns the RTSA’s identification information string.

Returns:“<Manufacturer>,<Model>,<Serial number>,<Firmware version>”

Resets the RTSA to its default configuration. It does not affect the registers or queues associated with the IEEE mandated commands.


This command queries the lock status of the RF VCO (Voltage Control Oscillator) in the Radio Front End (RFE) or the lock status of the PLL reference clock in the digitizer card.

Parameters:modulestr (str) – ‘VCO’ for rf lock status, ‘CLKREF’ for ref clock lock status
Returns:True if locked

Data Acquisition Related Methods:

  • Get permission:

Check if there is VRT data to read.

Returns:True if there is a packet to read, False if not

Acquire exclusive permission to read data from the RTSA.

Returns:True if allowed to read, False if not

Check if we have permission to read data from the RTSA.

Returns:True if allowed to read, False if not
  • Set capture size for stream or block mode capture:

This command sets the number of IQ packets in a capture block

Parameters:packets (int) – the number of packets for a block of capture, or None to query
Returns:the current ppb value if the packets parameter is None

This command sets or queries the number of Samples Per [VRT] Packet (SPP).

The upper bound of the samples is limited by the VRT’s 16-bit packet size field. However, since the SPP must be a multiple of 32, the maximum is thus limited by (2**16 - 32) or 65504.

Parameters:samples (int) – the number of samples in a VRT packet (256 to 65504, a multiple of 32), or None to query
Returns:the current spp value if the samples parameter is None
  • Stream setup

This query returns the current running status of the stream capture mode.

Returns:‘RUNNING’ or ‘STOPPED’

This command begins the execution of the stream capture. It will also initiate data capturing. Data packets will be streamed (or pushed) from the RTSA whenever data is available.

Parameters:stream_id (int) – optional unsigned 32-bit stream identifier

This command stops the stream capture. After receiving the command, the RTSA system will stop when the current capturing VRT packet is completed. Recommend calling flush() after stopping.

  • Sweep setup:

Add a sweep entry to the sweep list

Parameters:entry (pyrf.sweepDevice.sweepSettings) – the sweep entry settings to add to the list

Remove all entries from the sweep list.


Set or query the number of iterations to loop through a sweep list.

Parameters:count (int) – the number of iterations, 0 for infinite, or None to query
Returns:the current number of iterations if count is None

Read a sweep entry at the given sweep index from the sweep list.

Parameters:index – the index of the entry to read
Returns:settings of that sweep entry
Return type:pyrf.config.SweepEntry

Start the sweep engine with an optional ID.

Parameters:start_id (int) – An optional 32-bit ID to identify the sweep

Stop the sweep engine. Recommend calling flush() after stopping.

  • VRT data acquisition related methods:
capture(spp, ppb)

This command will start the single block capture of ppb packets of spp samples in each packet. The data within a single block capture trace is continuous from one packet to the other, but not necessary between successive block capture commands issued. Used for stream or block capture mode. To read data back, use read() method. See as an example.

  • spp (int) – the number of samples in a VRT packet
  • ppb (int) – the number of packets in a block of capture

This command queries the current capture mode

Returns:the current capture mode

Raw read of VRT socket data of num bytes from the RTSA.

Parameters:num (int) – the number of bytes to read

Read and return a single parsed VRT packet from the RTSA, either context or data.


Read and return a data packet, as well as computed power spectral density data, of spp (samples per packet) size, the associated context info and the computed power spetral data. If a block of data is requested (such as ppb is more than 1), loop through this function to retreive all data. See also data other capture functions: pyrf.util.capture_spectrum(), pyrf.capture_device.capture_time_domain()

Parameters:spp (int) – the number of samples in a VRT packet (256 to 65504) in a multiple of 32
Returns:data, context dictionary, and power spectral data array

This command will cause the RTSA to stop the data capturing, whether in the manual trace block capture, triggering or sweeping mode. The RTSA will be put into the manual mode; in other words, process such as streaming, trigger and sweep will be stopped. The capturing process does not wait until the end of a packet to stop, it will stop immediately upon receiving the command.


This command clears the RTSA’s internal data storage buffer of any data that is waiting to be sent. Thus, it is recommended that the flush command should be used when switching between different capture modes to clear up the remnants of captured packets.


Check if the VRT stream has closed.

Returns:True if no more data, False if more data

Device Configuration Methods for Non-Sweep Setup:


This command enables, disables or queries the RTSA’s RFE attenuation.

Parameters:atten_val – see Programmer’s Guide for the attenuation value to use for your product; None to query
Returns:the current attenuation value if None is used

This command sets or queries the rate of decimation of samples in a trace capture. The supported rate is 4 - 1024. When the rate is set to 1, no decimation is performed on the trace capture.

Parameters:value (int) – new decimation value (1 or 4 - 1024); None to query
Returns:the decimation value if None is used

This command sets or queries the tuned center frequency of the RTSA.

Parameters:freq (int) – the center frequency in Hz (range vary depnding on the product model); None to query
Returns:the frequency in Hz if None is used

This command sets or queries the frequency shift value.

Parameters:freq (int) – the frequency shift in Hz (0 - 125 MHz); None to query
Returns:the amount of frequency shift if None is used

This command sets or queries the HDR gain of the receiver. The gain has a range of -10 to 30 dB.

Parameters:gain (int) – float between -10 and 30 to set; None to query
Returns:the hdr gain in dB if None is used

This command sets or queries the RTSA’s current IQ path. It is not applicable to R5700.

Parameters:path (str) – ‘DIGITIZER’, ‘CONNECTOR’, ‘HIF’, or None to query
Returns:the current IQ output path type if None is used

This command sets or queries the RTSA’s PLL reference source

Parameters:src (str) – ‘INT’, ‘EXT’, ‘GPS’ (when available with the model) or None to query
Returns:the current PLL reference source if None is used

This command sets or queries one of the Pre-Select Filter Modules’s (PSFM) gain stages.

Parameters:gain (str) – sets the gain value to ‘high’, ‘medium’, ‘low’, or None to query
Returns:the RF gain value if None is used



This command sets or queries the RTSA’s Receiver Front End (RFE) mode of operation.

Parameters:mode (str) – ‘ZIF’, ‘DD’, ‘HDR’, ‘SHN’, ‘SH’, or None to query
Returns:the current RFE mode if None is used

This command sets or queries the type of trigger event. Setting the trigger type to “NONE” is equivalent to disabling the trigger execution; setting to any other type will enable the trigger engine.

Parameters:settings (dictionary) – the new trigger settings; None to query
Returns:the trigger settings if None is used
apply_device_settings(settings, force_change=False)

This command takes a dict of device settings, and applies them to the RTSA

  • settings (dict) – dict containing device’s settings such as attenuation, decimation, etc
  • force_change (bool) – to force the change update or not

DSP and Data Processing Related Methods:

measure_noisefloor(rbw=None, average=1)

Returns a power level that represents the top edge of the noisefloor

  • rbw (int) – rbw of spectral capture (Hz) (will round to nearest native RBW) or None
  • average (int) – number of capture iterations


peakfind(n=1, rbw=None, average=1)

Returns frequency and the power level of the maximum spectral point computed using the current settings, Note this function disables

  • n (int) – determine the number of peaks to return
  • rbw (int) – rbw of spectral capture (Hz) (will round to nearest native RBW) or None
  • average (int) – number of capture iterations

[(peak_freq1, peak_power1), (peak_freq2, peak_power2) , …, (peak_freqn, peak_powern)]

Data Recording Related Methods:


Inject the current RTSA state into the recording stream when the next capture is received. Replaces previous data if not yet sent.


Dump a recording of all the received packets to output_file

Device Discovery Functions:


This function parses the RTSA’s raw discovery response

Parameters:response – The RTSA’s raw response to a discovery query
Returns:Return (model, serial, firmware version) based on a discovery response message



class pyrf.connectors.blocking.PlainSocketConnector

This connector makes SCPI/VRT socket connections using plain sockets, of blocking type.

pyrf.connectors.blocking.socketread(socket, count, flags=None)

Retry socket read until count amount of data received, like reading from a file.

  • count (int) – the amount of data received
  • flags – socket.recv() related flags


class pyrf.connectors.twisted_async.TwistedConnector(reactor, vrt_callback=None)

A connector that makes SCPI/VRT connections asynchronously using Twisted method.

  • reactor – a twisted reactor, (ex: “from twisted.internet import reactor”)
  • vrt_callback (callback) – A callback may be assigned to vrt_callback that will be called with VRT packets as they arrive. When vrt_callback is None (the default), arriving packets will be ignored.
exception pyrf.connectors.twisted_async.TwistedConnectorError
class pyrf.connectors.twisted_async.VRTClient(receive_callback)

A Twisted protocol for the VRT connection.

Parameters:receive_callback – a function that will be passed a vrt DataPacket or ContextPacket when it is received


class pyrf.capture_device.CaptureDevice(real_device, async_callback=None, device_settings=None)

Virtual device that returns power levels generated from a single data packet

  • real_device – the device that will be used for capturing data, typically a pyrf.thinkrf.WSA instance.
  • async_callback – callback to use for async operation (not used if real_device is using a blocking PlainSocketConnector)
  • device_settings – initial device settings to use, passed to pyrf.capture_dvice.CaptureDevice.configure_device() if given
capture_time_domain(rfe_mode, freq, rbw, device_settings=None, min_points=256, force_change=False)

Initiate a capture of raw time domain IQ or I-only data

  • rfe_mode (str) – radio front end mode, e.g. ‘ZIF’, ‘SH’, …
  • freq (int) – center frequency in Hz to set
  • rbw (float) – the resolution bandwidth (RBW) in Hz of the data to be captured (output RBW may be smaller than requested)
  • device_settings (dict or None) – rfe_mode, freq, decimation, fshift and other device settings
  • min_points (int) – smallest number of data points per capture from the device
  • force_change (bool) – force the configuration to apply device_settings changes or not

(fstart, fstop, data) where fstart & fstop are frequencies in Hz & data is a list

configure_device(device_settings, force_change=False)

Configure the device settings on the next capture

  • device_settings (dict) – rfe mode, attenuation, decimation and other device settings
  • force_change (bool) – force the configuration to apply device_settings changes or not
exception pyrf.capture_device.CaptureDeviceError


class pyrf.sweep_device.SweepDevice(real_device, async_callback=None)

Virtual device that generates power spectrum from a given frequency range by sweeping the frequencies with a real device and piecing together the FFT results.

  • real_device – the RF device that will be used for capturing data, typically a pyrf.devices.thinkrf.WSA instance.
  • async_callback – a callback to use for async operation (not used if real_device is using a blocking PlainSocketConnector)
capture_power_spectrum(fstart, fstop, rbw, device_settings=None, mode='SH', continuous=False)

Initiate a data capture from the real_device by setting up a sweep list and starting a single sweep, and then return power spectral density data along with the actual sweep start and stop frequencies set (which might not be exactly the same as the requested fstart and fstop).


This function does not pipeline, and if the last sweep isn’t received before starting a new one, it will generate a failure.

  • fstart (int) – sweep starting frequency in Hz
  • fstop (int) – sweep ending frequency in Hz
  • rbw (float) – the resolution bandwidth (RBW) in Hz of the data to be captured (output RBW may be smaller than requested)
  • device_settings (dict) – attenuation and other device settings
  • mode (str) – sweep mode, ‘ZIF’, ‘SH’, or ‘SHN’
  • continuous (bool) – set sweep to be continuously or not (once only)

fstart, fstop, power_data

exception pyrf.sweep_device.SweepDeviceError

Exception for the sweep device to state an error() has occured

class pyrf.sweep_device.SweepPlanner(dev_prop)

An object that plans a sweep based on given paramaters.

Parameters:dev_prop (dict) – the sweep device properties
class pyrf.sweep_device.SweepSettings

An object used to keep track of the sweep settings


class pyrf.config.SweepEntry(fstart=2400000000, fstop=2400000000, fstep=100000000, fshift=0, decimation=0, gain='vlow', ifgain=0, hdr_gain=-10, spp=1024, ppb=1, trigtype='none', dwell_s=0, dwell_us=0, level_fstart=50000000, level_fstop=10000000000, level_amplitude=-100, attenuator=30, rfe_mode='SH')

Sweep entry setup for pyrf.devices.thinkrf.WSA.sweep_add()

  • fstart (int) – starting frequency in Hz
  • fstop (int) – ending frequency in Hz
  • fstep (int) – frequency step in Hz
  • fshift (int) – the frequency shift in Hz
  • decimation (int) – the decimation value (0 or 4 - 1023)
  • gain (str) – the RF gain value (‘high’, ‘medium’, ‘low’ or ‘vlow’)
  • ifgain (int) –

    the IF gain in dB (-10 - 34)


    parameter is deprecated, kept for a legacy device

  • hdr_gain (int) – the HDR gain in dB (-10 - 30)
  • spp (int) – samples per packet (256 - max, a multiple of 32) that fit in one VRT packet
  • ppb (int) – data packets per block
  • dwell_s (int) – dwell time seconds
  • dwell_us (int) – dwell time microseconds
  • trigtype (str) – trigger type (‘none’, ‘pulse’ or ‘level’)
  • level_fstart (int) – level trigger starting frequency in Hz
  • level_fstop (int) – level trigger ending frequency in Hz
  • level_amplitude (float) – level trigger minimum in dBm
  • attenuator – vary depending on the product
  • rfe_mode (str) – RFE mode to be used, such as ‘SH’, ‘SHN’, ‘DD’, etc.

a string list of the sweep entry’s settings

class pyrf.config.TriggerSettings(trigtype='NONE', fstart=None, fstop=None, amplitude=None)

Trigger settings for pyrf.devices.thinkrf.WSA.trigger().

  • trigtype (str) – “LEVEL”, “PULSE”, or “NONE” to disable
  • fstart (int) – trigger starting frequency in Hz
  • fstop (int) – trigger ending frequency in Hz
  • amplitude (float) – minimum level for trigger in dBm

a string in the format: TriggerSettings(trigger type, fstart, fstop, amplitude)

exception pyrf.config.TriggerSettingsError

Exception for the trigger settings to state an error() has occured



Return a dBm value representing the channel power of the input power spectrum.

Parameters:power_spectrum (list) – an array containing the power spectrum to be used for the channel power calculation
Returns:the channel power result
pyrf.numpy_util.calculate_occupied_bw(pow_data, span, occupied_perc)

Return the occupied bandwidth of a given spectrum, and occupied percentage

  • pow_data (list) – spectral data to be analyzed
  • span (int) – span of the given spectrum, in Hz
  • occupied_perc (float) – Percentage of the power to be measured

float value of the occupied bandwidth

pyrf.numpy_util.calibrate_time_domain(power_spectrum, data_pkt)

Return a list of the calibrated time domain data

  • power_spectrum (list) – spectral data of the time domain data
  • data_pkt (pyrf.vrt.DataPacket) – a RTSA VRT data packet

a list containing the calibrated time domain data

pyrf.numpy_util.compute_fft(dut, data_pkt, context, correct_phase=True, iq_correction_wideband=True, hide_differential_dc_offset=True, convert_to_dbm=True, apply_window=True, apply_spec_inv=True, apply_reference=True, ref=None, decimation=1)

Return an array of dBm values by computing the FFT of the passed data and reference level.

  • dut (pyrf.devices.thinkrf.WSA) – WSA device
  • data_pkt (pyrf.vrt.DataPacket) – packet containing samples
  • context (dict) – context values, such as ‘bandwidth’, ‘reflevel’, etc.
  • correct_phase (bool) – apply phase correction for captures with IQ data or not
  • iq_correction_wideband (bool) – apply wideband IQ correction or not
  • hide_differential_dc_offset (bool) – mask the differential DC offset present in captures with IQ data or not
  • convert_to_dbm (bool) – convert the output values to dBm or not
  • apply_window (bool) – apply windowing to FFT function or not
  • apply_spec_inv (bool) – apply spectral inversion to the FFT bin or not. Recommend to leave as default
  • apply_reference (bool) – apply reference level correction or not
  • ref (float) – a reference value to apply to the noise level
  • decimation (int) – the decimation value (1, 4 - 1024)

numpy array of spectral data in dBm, as floats


pyrf.util.capture_spectrum(dut, rbw=None, average=1, dec=1, fshift=0)

Returns the spectral data, and the usable start and stop frequencies corresponding to the RTSA’s current configuration

  • rbw (int) – rbw of spectral capture (Hz) (will round to nearest native RBW)
  • average (int) – number of capture iterations
  • dec (int) – decimation factor applied
  • fshift (int) – the fshift applied, in Hz

(fstart, fstop, pow_data) where pow_data is a list

pyrf.util.read_data_and_context(dut, points=1024)

Initiate capture of one VRT data packet, wait for and return data packet and collect preceeding context packets.

Parameters:points (int) – Number of data points to capture
Returns:(data_pkt, context_values)

Where context_values is a dict of {field_name: value} items from all the context packets received.


class pyrf.vrt.ContextPacket(packet_type, count, size, tmpstr, has_timestamp)

A Context Packet received from See VRT section of the product’s Programmer’s Guide for more information.

  • packet_type – VRT packet type
  • count – VRT packet counter (see VRT protocol)
  • size (int) – The VRT packet size, less headers and trailer words
  • tmpstr – hold the raw data for parsing
  • has_timestamp (bool) – to indicate timestamp is available with the packet

a dict containing field names and values from the packet

Parameters:ptype (str) – “Receiver”, “Digitizer” or None for any packet type
Returns:True if this packet matches the ptype passed

To indicate this VRT packet is not of data type as it’s a ContextPacket

class pyrf.vrt.DataPacket(count, size, stream_id, tsi, tsf, payload, trailer)

A Data Packet received from


a pyrf.vrt.IQData object containing the packet data

class pyrf.vrt.IQData(binary_data)

Data Packet values as a lazy collection of (I, Q) tuples read from binary_data.

This object behaves as an immutable python sequence, e.g. you may do any of the following:

points = len(iq_data)

i_and_q = iq_data[5]

for i, q in iq_data:
    print i, q

Return a numpy array of I, Q values for this data

exception pyrf.vrt.InvalidDataReceived

Read a VRT packet, parse it and return an object with its data.

Implemented as a generator that yields the result of the passed raw_read function and accepts the value sent as its data.

Parameters:raw_read (list) – VRT packet of raw data (bytes)