Frequency Counters

Devices

Device	Tested	Connection
Agilent 53181A	01/2021	GPIB (linux-gpib), RS-232
Agilent 53131A / 53132A	01/2021	GPIB (linux-gpib), RS-232
Agilent 5343A	02/2023	GPIB
Keysight 53230A / 53220A	Untested	GPIB (linux-gpib), RS-232, Ethernet

Functions

freq_counter_name()

freq_counter_name()    # -> str; device name

This function returns device name.

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freq_counter_frequency(channel)

freq_counter_frequency('CH1')    # -> str; measured frequency from channel 1

This function returns a value with the measured frequency from the specified channel. Refer to the device manual for the frequency range of different channels. Agilent 53181a has two channels; Agielnt 53131a, Keysight 53230a - three. Agielnt 5343a has only one channel.

Allowed channels: 'CH1', 'CH2', 'CH3'

Output format: 'number' + 'Hz' | 'kHz' | 'MHz' | 'GHz'

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freq_counter_impedance(*impedance)

freq_counter_impedance('CH1', '1 M')    # set channel 1 impedance to 1 MOhm
freq_counter_impedance('CH2')           # -> str; current impedance of channel 2

This function queries (if called with one argument) or sets (if called with two arguments) the impedance of one of the channels of the frequency counter. If there is a second argument it will be set as a new impedance. If there is no second argument the current impedance for the specified channel is returned.

For Agilent 53181a impedance can be changed only for the first channel; for Agielnt 53131a, Keysight 53230a for channel 1 and 2.

Allowed channels: 'CH1', 'CH2', 'CH3'

Allowed impedances: '1 M', '50'

Note

This function is not available for Agielnt 5343a.

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freq_counter_coupling(*coupling)

freq_counter_coupling('CH1', 'AC')    # set channel 1 coupling to AC
freq_counter_coupling('CH2')          # -> str; current coupling of channel 2

This function queries (if called with one argument) or sets (if called with two arguments) the coupling of one of the channels of the frequency counter. If there is a second argument it will be set as a new coupling. If there is no second argument the current coupling for the specified channel is returned.

For Agilent 53181a coupling can be changed only for the first channel; for Agielnt 53131a, Keysight 53230a for channel 1 and 2.

Allowed channels: 'CH1', 'CH2', 'CH3'

Allowed couplings: 'AC', 'DC'

Note

This function is not available for Agielnt 5343a.

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freq_counter_stop_mode(*mode)

freq_counter_stop_mode()           # -> str (query)
freq_counter_stop_mode('Timer')    # set the gate time mode

This function queries or sets the stop arm for frequency, frequency ratio, and period measurements.

In automatic ('Immediate') mode the device does the fastest possible acquisistion, in gate time mode it measures for the specified gate time, and in digits mode the time required for a measurement depends on the number of digits requested. This setting influences the resolution of the results. Use automatic mode for fast measurements or choose a desired resolution by using freq_counter_gate_time() to set the gate time for gate time ('Timer') mode or freq_counter_digits() for digits ('Digits') mode.

Allowed (Agilent 53181a, 53131a): 'Immediate', 'External', 'Timer', 'Digits'

Allowed (Keysight 53230a): 'Immediate', 'Timer', 'Events'

Note

This function is not available for Agielnt 5343a.

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freq_counter_start_mode(*mode)

freq_counter_start_mode()               # -> str (query)
freq_counter_start_mode('Immediate')    # set automatic mode

This function queries or sets the start arm for frequency, frequency ratio, and period measurements.

Allowed: 'Immediate', 'External'

Note

This function is not available for Agielnt 5343a.

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freq_counter_gate_mode(*mode)

freq_counter_gate_mode()           # -> str (query)
freq_counter_gate_mode('Timer')    # set 'Timer' mode

This function queries or sets the gate source for frequency, frequency ratio measurements. 'Timer' coresponds to starting the measurement immediately after a trigger and trigger delay; 'External' configures the instrument to gate the measurement using the Gate In/Out BNC after a trigger and trigger delay.

Allowed: 'Timer', 'External'

Note

This function is available only for Keysight 53230a.

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freq_counter_digits(*digits)

freq_counter_digits()     # -> int (query)
freq_counter_digits(5)    # set resolution to 5 digits

This function queries or sets the resolution in terms of digits used in arming frequency, period, and ratio measurements. To set this mode use freq_counter_stop_mode() function. To query the number of digits call the function with no argument. A query is possible only if freq_counter_stop_mode('Digits') was called before.

Range (Agilent 53181a, 53131a): 3 – 15

Range (Agilent 5343a): 3 – 9

Note

This function is available for Agilent 53181a, 53131a, and 5343a.

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freq_counter_gate_time(*time)

freq_counter_gate_time()            # -> float (query)
freq_counter_gate_time('100 ms')    # set gate time to 100 ms

This function queries or sets the gate time used in arming frequency, period, and ratio measurements. To set this mode use freq_counter_stop_mode() function. To query the gate call the function with no argument. A query is possible only if freq_counter_stop_mode('Timer') was called before.

Output format: 'number' + 'ks' | 's' | 'ms' | 'us' | 'ns'

Range (Agilent 53181a, 53131a): 1 ms – 1000 s

Range (Keysight 53230a): 10 ns – 10 s

Note

This function is not available for Agielnt 5343a.

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freq_counter_expected_freq(*frequency)

freq_counter_expected_freq('CH3', '10 GHz')    # set approximate signal frequency to 10 GHz
freq_counter_expected_freq('CH3')              # -> str; query approximate frequency

This function queries (if called with one argument) or sets (if called with two arguments) the approximate frequency of a signal you expect to measure. Providing this value enables the device to eliminate a pre-measurement step, saving measurement time and enabling more accurate arming. Note that the actual frequency of the input signal must be within 10% of the expected frequency value you entered. Refer to the device manual for the frequency range of different channels.

If there is a second argument it will be set as a new approximate frequency of a signal. If there is no second argument the current approximate frequency of a signal for specified the channel is returned. For Agilent 53181a the approximate frequency can be set for channels 1 and 2; for Agielnt 53131a for channels 1, 2, and 3.

Allowed channels: 'CH1', 'CH2', 'CH3'

Output format: 'number' + 'Hz' | 'kHz' | 'MHz' | 'GHz'

Note

This function is available only for Agilent 53181a and 53131a.

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freq_counter_period(channel)

freq_counter_period('CH2')    # -> str; measured period from channel 2

This function returns a floating point value with the measured period from the specified channel. Refer to the device manual for the frequency range of different channels.

Allowed channels: 'CH1', 'CH2', 'CH3'

Output format: 'number' + 's' | 'ms' | 'us' | 'ns'

Note

This function is available only for Agilent 53181a and 53131a.

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freq_counter_command(command)

# Set which edge of the input signal will be considered an event for frequency,
# period, frequency ratio, time interval, totalize, and phase measurements.
freq_counter_command(':EVENt1:SLOPe POSitive')

This function sends an arbitrary command from a programming guide to the device in a string format. No output is expected.

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freq_counter_query(command)

# Query a measurement of the phase between channel 1 and 2.
freq_counter_query(':MEASure:PHASe? (@1),(@2)')

This function sends an arbitrary command from a programming guide to the device in a string format. An output in a string format is expected.