ObwResults

Provides methods to fetch and read the Obw measurement results.

class nirfmxspecan.obw_results.ObwResults(signal_obj)

Bases: object

Provides methods to fetch and read the Obw measurement results.

fetch_measurement(selector_string, timeout)

Returns the occupied bandwidth (OBW) measurement.

Parameters:

• selector_string (string) –

  This parameter specifies a Selector String comprising of result name.

  Example:

  ””

  ”result::r1”

  You can use the build_result_string() method to build the selector string.

• timeout (float) – This parameter specifies the timeout, in seconds, for fetching the specified measurement. Set this value to an appropriate time, longer than expected for fetching the measurement. A value of -1 specifies that the method waits until the measurement is complete. The default value is 10.

Returns:

occupied_bandwidth (float):

This parameter returns the occupied bandwidth, in Hz.

average_power (float):

This parameter returns the total integrated power of the averaged spectrum acquired by the OBW measurement when you set the POWER_UNITS attribute to dBm. This method returns the power spectral density when you set the OBW Power Units attribute to dBm/Hz.

frequency_resolution (float):

This parameter returns the frequency bin spacing, in Hz, of the spectrum acquired by the measurement.

start_frequency (float):

This parameter returns the start frequency, in Hz, of the OBW. The OBW is calculated using the following formula: OBW = stop frequency - start frequency

stop_frequency (float):

This parameter returns the stop frequency, in Hz, of the OBW.

error_code (int):

Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

Tuple (occupied_bandwidth, average_power, frequency_resolution, start_frequency, stop_frequency, error_code)

fetch_spectrum_trace(selector_string, timeout, spectrum)

Fetches the spectrum trace used for the OBW measurement.

Parameters:

• selector_string (string) –

  This parameter specifies a Selector String comprising of result name.

  Example:

  ””

  ”result::r1”

  You can use the build_result_string() method to build the selector string.

• timeout (float) – This parameter specifies the timeout, in seconds, for fetching the specified measurement. Set this value to an appropriate time, longer than expected for fetching the measurement. A value of -1 specifies that the method waits until the measurement is complete. The default value is 10.

• spectrum (numpy.float32) – This parameter returns the array of averaged powers measured at each frequency bin. This value is expressed in dBm.

Returns:

x0 (float):

This parameter returns the start frequency. This value is expressed in Hz.

dx (float):

This parameter returns the frequency bin spacing. This value is expressed in Hz.

error_code (int):

Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

Tuple (x0, dx, error_code)

get_average_power(selector_string)

Gets the total integrated power, in dBm, of the averaged spectrum acquired by the OBW measurement when you set the POWER_UNITS attribute to dBm. The OBW Results Avg Pwr attribute returns the power spectral density, in dBm/Hz, when you set the OBW Power Units attribute to dBm/Hz.

You do not need to use a selector string to read this result for default signal and result instance. Refer to the Selector String topic for information about the string syntax for named signals and results.

Parameters:

selector_string (string) – Pass an empty string.

Returns:

attr_val (float):

Returns the total integrated power, in dBm, of the averaged spectrum acquired by the OBW measurement when you set the POWER_UNITS attribute to dBm. The OBW Results Avg Pwr attribute returns the power spectral density, in dBm/Hz, when you set the OBW Power Units attribute to dBm/Hz.

error_code (int):

Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

Tuple (attr_val, error_code)

get_frequency_resolution(selector_string)

Gets the frequency bin spacing of the spectrum acquired by the OBW measurement. This value is expressed in Hz.

You do not need to use a selector string to read this result for default signal and result instance. Refer to the Selector String topic for information about the string syntax for named signals and results.

Parameters:

selector_string (string) – Pass an empty string.

Returns:

attr_val (float):

Returns the frequency bin spacing of the spectrum acquired by the OBW measurement. This value is expressed in Hz.

error_code (int):

Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

Tuple (attr_val, error_code)

get_occupied_bandwidth(selector_string)

Gets the bandwidth that occupies the percentage of the total power of the signal that you specify in the BANDWIDTH_PERCENTAGE attribute. This value is expressed in Hz.

You do not need to use a selector string to read this result for default signal and result instance. Refer to the Selector String topic for information about the string syntax for named signals and results.

Parameters:

selector_string (string) – Pass an empty string.

Returns:

attr_val (float):

Returns the bandwidth that occupies the percentage of the total power of the signal that you specify in the BANDWIDTH_PERCENTAGE attribute. This value is expressed in Hz.

error_code (int):

Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

Tuple (attr_val, error_code)

get_start_frequency(selector_string)

Gets the start frequency of the OBW. This value is expressed in Hz.

The OBW is calculated using the following formula: OBW = stop frequency - start frequency

You do not need to use a selector string to read this result for default signal and result instance. Refer to the Selector String topic for information about the string syntax for named signals and results.

Parameters:

selector_string (string) – Pass an empty string.

Returns:

attr_val (float):

Returns the start frequency of the OBW. This value is expressed in Hz.

error_code (int):

Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

Tuple (attr_val, error_code)

get_stop_frequency(selector_string)

Gets the stop frequency of the OBW. This value is expressed in Hz.

The OBW is calculated using the following formula: OBW = stop frequency - start frequency

You do not need to use a selector string to read this result for default signal and result instance. Refer to the Selector String topic for information about the string syntax for named signals and results.

Parameters:

selector_string (string) – Pass an empty string.

Returns:

attr_val (float):

Returns the stop frequency of the OBW. This value is expressed in Hz.

error_code (int):

Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

Tuple (attr_val, error_code)

read(selector_string, timeout)

Configures hardware for acquisition, performs measurement on acquired data, and returns occupied bandwidth (OBW) measurement results.

Parameters:

• selector_string (string) – Pass an empty string. The signal name that is passed when creating the signal configuration is used.

• timeout (float) – This parameter specifies the timeout, in seconds, for fetching the specified measurement. Set this value to an appropriate time, longer than expected for fetching the measurement. The default value is 10.

Returns:

occupied_bandwidth (float):

This parameter returns the occupied bandwidth, in Hz.

average_power (float):

This parameter returns the total integrated power of the averaged spectrum acquired by the OBW measurement when you set the POWER_UNITS attribute to dBm. This method returns the power spectral density when you set the OBW Power Units attribute to dBm/Hz.

frequency_resolution (float):

This parameter returns the frequency bin spacing, in Hz, of the spectrum acquired by the OBW measurement.

start_frequency (float):

This parameter returns the start frequency, in Hz, of the OBW. The OBW is calculated using the following formula: OBW = stop frequency - start frequency

stop_frequency (float):

This parameter returns the stop frequency, in Hz, of the OBW.

error_code (int):

Returns the status code of this method. The status code either indicates success or describes a warning condition.

Return type:

Tuple (occupied_bandwidth, average_power, frequency_resolution, start_frequency, stop_frequency, error_code)