Diffusion Instrument Control (TekRSA-Freq-vs-Time) Browse

MyZiRingdown.m
43180a46f866TekRSA-Freq-vs-Time

MyZiRingdown.m
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			% Class for performing ringdown measurements of mechanical oscillators
			% using Zurich Instruments UHF or MF lock-in.
			%
			% Operation: sweep the driving tone (drive_osc) using the sweep module
			% in LabOne web user interface, when the magnitude of the demodulator
			% signal exceeds trig_threshold the driving tone is switched off and
			% the recording of demodulated signal is started, the signal is recorded
			% for the duration of record_time.
			%
			% Features:
			%
			% Adaptive measurement oscillator frequency
			%
			% Averaging
			%
			% Auto saving
			%
			% Auxiliary output signal: If enable_aux_out=true
			% then after a ringdown is started a sequence of pulses is applied
			% to the output consisting of itermittent on and off periods
			% starting from on.

			classdef MyZiRingdown < MyZiLi & MyDataSource

			properties (Access=public)
			% Ringdown is recorded if the signal in the triggering demodulation
			% channel exceeds this value
			trig_threshold=1e-3 % V

			% Duration of the recorded ringdown
			record_time=1 % (s)

			% If enable_acq is true, then the drive is on and the acquisition
			% of record is triggered when signal exceeds trig_threshold
			enable_acq=false

			% Auxiliary output signal during ringdown.
			enable_aux_out=false % If auxiliary output is applied
			% time during which the output is in aux_out_on_lev state
			aux_out_on_t=1 % (s)
			% time during which the output is in aux_out_off_lev state
			aux_out_off_t=1 % (s)

			aux_out_on_lev=1 % (V), output trigger on level
			aux_out_off_lev=0 % (V), output trigger off level

			% Average the trace over n points to reduce amount of stored data
			% while keeping the demodulator bandwidth large
			downsample_n=1

			fft_length=128

			auto_save=false % if all ringdowns should be automatically saved

			% In adaptive measurement oscillator mode the oscillator frequency
			% is continuously changed to follow the signal frequency during
			% ringdown acquisition. This helps against the oscillator frequency
			% drift.
			adaptive_meas_osc=false
			end

			% The properties which are read or set only once during the class
			% initialization
			properties (GetAccess=public, SetAccess={?MyClassParser})
			% enumeration for demodulators, oscillators and output starts from 1
			demod=1 % demodulator used for both triggering and measurement

			% Enumeration in the node structure starts from 0, so, for example,
			% the default path to the trigger demodulator refers to the
			% demodulator #1
			demod_path='/dev4090/demods/0'

			drive_osc=1
			meas_osc=2

			% Signal input, integers above 1 correspond to main inputs, aux
			% input etc. (see the user interface for device-specific details)
			signal_in=1

			drive_out=1 % signal output used for driving

			% Number of an auxiliary channel used for the output of triggering
			% signal, primarily intended to switch the measurement apparatus
			% off during a part of the ringdown and thus allow for free
			% evolution of the oscillator during that period.
			aux_out=1

			% Poll duration of 1 ms practically means that ziDAQ('poll', ...
			% returns immediately with the data accumulated since the
			% previous function call.
			poll_duration=0.001 % s
			poll_timeout=50 % ms

			% Margin for adaptive oscillator frequency adjustment - oscillator
			% follows the signal if the dispersion of frequency in the
			% demodulator band is below ad_osc_margin times the demodulation
			% bandwidth (under the condition that adaptive_meas_osc=true)
			ad_osc_margin=0.1
			end

			% Internal variables
			properties (GetAccess=public, SetAccess=protected)
			recording=false % true if a ringdown is being recorded

			% true if adaptive measurement oscillator mode is on and if the
			% measurement oscillator is actually actively following.
			ad_osc_following=false

			% Reference timestamp at the beginning of measurement record.
			% Stored as uint64.
			t0

			elapsed_t=0 % Time elapsed since the last recording was started

			DemodSpectrum % MyTrace object to store FFT of the demodulator data
			end

			% Setting or reading the properties below automatically invokes
			% communication with the device
			properties (Dependent=true)
			drive_osc_freq
			meas_osc_freq
			drive_on % true when the dirive output is on

			% demodulator sampling rate (as transferred to the computer)
			demod_rate

			% The properties below are only used within the program to display
			% the information about device state.
			drive_amp % (V), peak-to-peak amplitude of the driving tone
			lowpass_order % low-pass filter order
			lowpass_bw % low-pass filter bandwidth
			end

			% Other dependent variables that are dont device properties
			properties (Dependent=true)
			% Downsample the measurement record to reduce the amount of data
			% while keeping the large demodulation bandwidth.
			% (samples/s), sampling rate of the trace after avraging
			downsampled_rate

			% number of the oscillator presently in use with the demodulator
			current_osc

			% true/false, true if the signal output from aux out is in on state
			aux_out_on

			% Provides public access to properties of private AvgTrace
			n_avg % number of ringdowns to be averaged
			avg_count % the average counter

			fft_rbw % resolution bandwidth of fft
			end

			% Keeping handle objects fully private is the only way to restrict set
			% access to their properties
			properties (Access=private)
			PollTimer

			AuxOutOffTimer % Timer responsible for switching the aux out off
			AuxOutOnTimer % Timer responsible for switching the aux out on

			% Demodulator samples z(t) stored to continuously calculate
			% spectrum, values of z are complex here, z=x+iy.
			% osc_freq is the demodulation frequency
			DemodRecord=struct('t',[],'z',[],'osc_freq',[])

			AvgTrace % MyAvgTrace object used for averaging ringdowns
			end

			events
			NewDemodSample % New demodulator samples received
			RecordingStarted % Acquisition of a new trace triggered
			end

			methods (Access=public)

			%% Constructor and destructor
			function this = MyZiRingdown(dev_serial, varargin)
			this=this@MyZiLi(dev_serial);

			P=MyClassParser(this);
			addRequired(P, dev_serial, @ischar)
			% Poll timer period
			addParameter(P,'poll_period',0.042,@isnumeric);
			processInputs(P, this, dev_serial, varargin{:});

			% Create and configure trace objects
			% Trace is inherited from the superclass
			this.Trace=MyTrace(...
			'name_x','Time',...
			'unit_x','s',...
			'name_y','Magnitude r',...
			'unit_y','V');
			this.DemodSpectrum=MyTrace(...
			'name_x','Frequency',...
			'unit_x','Hz',...
			'name_y','PSD',...
			'unit_y','V^2/Hz');
			this.AvgTrace=MyAvgTrace();

			% Set up the poll timer. Using a timer for anyncronous
			% data readout allows to use the wait time for execution
			% of other programs.
			% Fixed spacing is preferred as it is the most robust mode of
			% operation when keeping the intervals between callbacks
			% precisely defined is not the biggest concern.
			this.PollTimer=timer(...
			'ExecutionMode','fixedSpacing',...
			'Period',P.Results.poll_period,...
			'TimerFcn',@(~,~)pollTimerCallback(this));

			% Aux out timers use fixedRate mode for more precise timing.
			% The two timers are executed periodically with a time lag.
			% The first timer switches the auxiliary output off
			this.AuxOutOffTimer=timer(...
			'ExecutionMode','fixedRate',...
			'TimerFcn',@(~,~)auxOutOffTimerCallback(this));
			% The second timer switches the auxiliary output on
			this.AuxOutOnTimer=timer(...
			'ExecutionMode','fixedRate',...
			'TimerFcn',@(~,~)auxOutOnTimerCallback(this));

			this.demod_path = sprintf('/%s/demods/%i', this.dev_id, ...
			this.demod-1);
			end

			function delete(this)
			% delete function should never throw errors, so protect
			% statements with try-catch
			try
			stopPoll(this)
			catch
			warning(['Could not usubscribe from the demodulator ', ...
			'or stop the poll timer.'])
			end
			% Delete timers to prevent them from running indefinitely in
			% the case of program crash
			try
			delete(this.PollTimer)
			catch
			warning('Could not delete the poll timer.')
			end
			try
			stop(this.AuxOutOffTimer);
			delete(this.AuxOutOffTimer);
			catch
			warning('Could not stop and delete AuxOutOff timer.')
			end
			try
			stop(this.AuxOutOnTimer);
			delete(this.AuxOutOnTimer);
			catch
			warning('Could not stop and delete AuxOutOn timer.')
			end
			end

			%% Other methods

			function startPoll(this)
			% Configure the oscillators, demodulator and driving output
			% -1 accounts for the difference in enumeration conventions
			% in the software names (starting from 1) and node numbers
			% (starting from 0).
			% First, update the demodulator path
			this.demod_path = sprintf('/%s/demods/%i', ...
			this.dev_id, this.demod-1);

			% Set the data transfer rate so that it satisfies the Nyquist
			% criterion (>x2 the bandwidth of interest)
			this.demod_rate=4*this.lowpass_bw;

			% Configure the demodulator. Signal input:
			ziDAQ('setInt', ...
			[this.demod_path,'/adcselect'], this.signal_in-1);
			% Oscillator:
			ziDAQ('setInt', ...
			[this.demod_path,'/oscselect'], this.drive_osc-1);
			% Enable data transfer from the demodulator to the computer
			ziDAQ('setInt', [this.demod_path,'/enable'], 1);

			% Configure the signal output - disable all the oscillator
			% contributions excluding the driving tone
			path = sprintf('/%s/sigouts/%i/enables/*', ...
			this.dev_id, this.drive_out-1);
			ziDAQ('setInt', path, 0);
			path = sprintf('/%s/sigouts/%i/enables/%i', ...
			this.dev_id, this.drive_out-1, this.drive_osc-1);
			ziDAQ('setInt', path, 1);

			% Enable output
			this.drive_on=true;

			% By convention, we start form 'enable_acq=false' state
			this.enable_acq=false;

			% Configure the auxiliary trigger output - put it in the manual
			% mode so it does not output demodulator readings
			path=sprintf('/%s/auxouts/%i/outputselect', ...
			this.dev_id, this.aux_out-1);
			ziDAQ('setInt', path, -1);
			% The convention is that aux out is on by default
			this.aux_out_on=true;

			% Subscribe to continuously receive samples from the
			% demodulator. Samples accumulated between timer callbacks
			% will be read out using ziDAQ('poll', ...
			ziDAQ('subscribe',[this.demod_path,'/sample']);

			% Start continuous polling
			start(this.PollTimer)
			end

			function stopPoll(this)
			stop(this.PollTimer)
			ziDAQ('unsubscribe',[this.demod_path,'/sample']);
			end

			% Main function that polls data from the device demodulator
			function pollTimerCallback(this)

			% ziDAQ('poll', ... with short poll_duration returns
			% immediately with the data accumulated since the last timer
			% callback
			Data = ziDAQ('poll', this.poll_duration, this.poll_timeout);

			if ziCheckPathInData(Data, [this.demod_path,'/sample'])
			% Demodulator returns data
			DemodSample= ...
			Data.(this.dev_id).demods(this.demod).sample;

			% Append new samples to the record and recalculate spectrum
			appendSamplesToBuff(this, DemodSample);
			calcfft(this);

			if this.recording
			% If the recording has just started, save the start
			% time
			if isempty(this.Trace)
			this.t0=DemodSample.timestamp(1);
			end

			% If recording is under way, append the new samples to
			% the trace
			rec_finished = appendSamplesToTrace(this, DemodSample);

			% Recording can be manually stopped by setting
			% enable_acq=false
			if ~this.enable_acq
			rec_finished=true;
			end

			% Update elapsed time
			this.elapsed_t=this.Trace.x(end);

			% If the adaptive measurement frequency mode is on,
			% update the measurement oscillator frequency.
			% Make sure that the demodulator record actually
			% contains signal by comparing the dispersion of
			% frequency to demodulator bandwidth.
			if this.adaptive_meas_osc
			[df_avg, df_dev]=calcfreq(this);
			if df_dev < this.ad_osc_margin*this.lowpass_bw
			this.meas_osc_freq=df_avg;
			% Change indicator
			this.ad_osc_following=true;
			else
			this.ad_osc_following=false;
			end
			else
			this.ad_osc_following=false;
			end
			else
			r=sqrt(DemodSample.x.^2+DemodSample.y.^2);
			if this.enable_acq && max(r)>this.trig_threshold
			% Start acquisition of a new trace if the maximum
			% of the signal exceeds threshold
			this.recording=true;
			this.elapsed_t=0;

			% Switch the drive off
			this.drive_on=false;

			% Set the measurement oscillator frequency to be
			% the frequency at which triggering occurred
			this.meas_osc_freq=this.drive_osc_freq;

			% Switch the oscillator
			this.current_osc=this.meas_osc;

			% Clear the buffer on ZI data server from existing
			% demodulator samples, as these samples were
			% recorded with drive on
			ziDAQ('poll',this.poll_duration,this.poll_timeout);

			% Optionally start the auxiliary output timers
			if this.enable_aux_out
			% Configure measurement periods and delays
			T=this.aux_out_on_t+this.aux_out_off_t;
			this.AuxOutOffTimer.Period=T;
			this.AuxOutOnTimer.Period=T;

			this.AuxOutOffTimer.startDelay=...
			this.aux_out_on_t;
			this.AuxOutOnTimer.startDelay=T;

			% Start timers
			start(this.AuxOutOffTimer)
			start(this.AuxOutOnTimer)
			end

			% Clear trace
			clearData(this.Trace);

			notify(this, 'RecordingStarted');
			end

			rec_finished=false;

			% Indicator for adaptive measurement is off, since
			% recording is not under way
			this.ad_osc_following=false;
			end

			notify(this,'NewDemodSample');

			% Stop recording if a record was completed
			if rec_finished
			% stop recording
			this.recording=false;
			this.ad_osc_following=false;

			% Stop auxiliary timers
			stop(this.AuxOutOffTimer);
			stop(this.AuxOutOnTimer);

			% Return the drive and aux out to the default state
			this.aux_out_on=true;
			this.current_osc=this.drive_osc;
			this.drive_on=true;

			% Downsample the trace to reduce the amount of data
			downsample(this.Trace, this.downsample_n, 'avg');

			% Do trace averaging. If the new data length is not of
			% the same size as the length of the existing data
			% (which should happen only when the record period was
			% changed during recording or when recording was
			% manually stopped), truncate to the minimum length
			if ~isempty(this.AvgTrace) && ...
			(length(this.AvgTrace.y)~=length(this.Trace.y))
			l=min(length(this.AvgTrace.y),length(this.Trace.y));
			this.AvgTrace.y=this.AvgTrace.y(1:l);
			this.AvgTrace.x=this.AvgTrace.x(1:l);
			this.Trace.y=this.Trace.y(1:l);
			this.Trace.x=this.Trace.x(1:l);
			disp('Ringdown record was truncated')
			end
			avg_compl=addAverage(this.AvgTrace, this.Trace);

			% Trigger NewData
			if this.n_avg>1
			end_str=sprintf('_%i', this.AvgTrace.avg_count);
			else
			end_str='';
			end
			triggerNewData(this, 'save', this.auto_save, ...
			'filename_ending', end_str);

			% If the ringdown averaging is complete, disable
			% further triggering to exclude data overwriting
			if avg_compl
			this.enable_acq=false;

			if this.n_avg>1
			end_str='_avg';
			% Trigger one more time to transfer the average
			% trace.
			% A new measurement header is not necessary
			% as the delay since the last triggering is
			% minimum.
			triggerNewData(this, ...
			'Trace', copy(this.AvgTrace), ...
			'save', this.auto_save, ...
			'filename_ending', end_str);
			end
			end
			end
			end
			end

			% Append timestamps vs r=sqrt(x^2+y^2) to the measurement record.
			% Starting index can be supplied as varargin.
			% The output variable tells if the record is finished.
			function isfin = appendSamplesToTrace(this, DemodSample)

			r=sqrt(DemodSample.x.^2 + DemodSample.y.^2);
			% Subtract the reference time, convert timestamps to seconds
			ts=double(DemodSample.timestamp - this.t0)/this.clockbase;

			% Check if recording should be stopped
			isfin=(ts(end)>=this.record_time);
			if isfin
			% Remove excess data points from the new data
			ind=(ts<this.record_time);
			ts=ts(ind);
			r=r(ind);
			end

			% Append the new data in column format to the trace
			this.Trace.x=[this.Trace.x; ts(:)];
			this.Trace.y=[this.Trace.y; r(:)];
			end

			% Append timestamps vs z=x+iy to the shift register for fft
			% calculation
			function appendSamplesToBuff(this, DemodSample)
			z=complex(DemodSample.x, DemodSample.y);
			t=double(DemodSample.timestamp)/this.clockbase;

			% Convert the new data to column format and append
			this.DemodRecord.t=[this.DemodRecord.t; t(:)];
			this.DemodRecord.z=[this.DemodRecord.z; z(:)];
			this.DemodRecord.osc_freq=[this.DemodRecord.osc_freq; ...
			DemodSample.frequency(:)];

			assert(length(this.DemodRecord.t)==length(this.DemodRecord.z), ...
			't and z=x+iy array lengths of DemodRecord are not equal.')

			% Only store the latest data points required to calculate fft
			flen=this.fft_length;
			if length(this.DemodRecord.t)>flen
			this.DemodRecord.t = this.DemodRecord.t(end-flen+1:end);
			this.DemodRecord.z = this.DemodRecord.z(end-flen+1:end);
			this.DemodRecord.osc_freq = ...
			this.DemodRecord.osc_freq(end-flen+1:end);
			end
			end

			function calcfft(this)
			flen=min(this.fft_length, length(this.DemodRecord.t));
			[freq, spectr]=xyFourier( ...
			this.DemodRecord.t(end-flen+1:end), ...
			this.DemodRecord.z(end-flen+1:end));
			this.DemodSpectrum.x=freq;
			this.DemodSpectrum.y=abs(spectr).^2;
			end

			% Calculate the average frequency and dispersion of the demodulator
			% signal
			function [f_avg, f_dev]=calcfreq(this)
			if ~isempty(this.DemodSpectrum)
			norm=sum(this.DemodSpectrum.y);

			% Calculate the center frequency of the spectrum
			f_avg=dot(this.DemodSpectrum.x, this.DemodSpectrum.y)/norm;

			f_dev=sqrt(dot(this.DemodSpectrum.x.^2, ...
			this.DemodSpectrum.y)/norm-f_avg^2);

			% Shift the FFT center by the demodulation frequency to
			% output absolute value
			f_avg=f_avg+mean(this.DemodRecord.osc_freq);
			else
			f_avg=[];
			f_dev=[];
			end
			end

			% Provide restricted access to private AvgTrace
			function resetAveraging(this)
			% Clear data and reset counter
			clearData(this.AvgTrace);
			notify(this,'NewSetting');
			end

			function auxOutOffTimerCallback(this)
			this.aux_out_on=false;
			end

			function auxOutOnTimerCallback(this)
			this.aux_out_on=true;
			end

			%% measurement header functionality

			function Hdr=readHeader(this)
			Hdr=readHeader@MyZiLi(this);

			% Demodulator parameters
			addObjProp(Hdr, this, 'demod', 'comment', ...
			'Number of the demodulator in use (starting from 1)');
			addObjProp(Hdr, this, 'demod_rate', 'comment', ...
			'(samples/s), demodulator data transfer rate');
			addObjProp(Hdr, this, 'lowpass_order', 'comment', ...
			'Order of the demodulator low-pass filter');
			addObjProp(Hdr, this, 'lowpass_bw', 'comment', ...
			['(Hz), 3 dB bandwidth of the demodulator low-pass ', ...
			'filter']);
			addObjProp(Hdr, this, 'meas_osc', 'comment', ...
			'Measurement oscillator number');
			addObjProp(Hdr, this, 'meas_osc_freq', 'comment', '(Hz)');

			% Signal input
			addObjProp(Hdr, this, 'signal_in', 'comment', ...
			'Singnal input number');

			% Drive parameters
			addObjProp(Hdr, this, 'drive_out', 'comment', ...
			'Driving output number');
			addObjProp(Hdr, this, 'drive_osc', 'comment', ...
			'Swept oscillator number');
			addObjProp(Hdr, this, 'drive_amp', 'comment', ...
			'(V) peak to peak');

			% Parameters of the auxiliary output
			addObjProp(Hdr, this, 'aux_out', 'comment', ...
			'Auxiliary output number');
			addObjProp(Hdr, this, 'enable_aux_out', 'comment', ...
			'Auxiliary output is applied during ringdown');
			addObjProp(Hdr, this, 'aux_out_on_lev', 'comment', '(V)');
			addObjProp(Hdr, this, 'aux_out_off_lev', 'comment', '(V)');
			addObjProp(Hdr, this, 'aux_out_on_t', 'comment', '(s)');
			addObjProp(Hdr, this, 'aux_out_off_t', 'comment', '(s)');

			% Software parameters
			addObjProp(Hdr, this, 'trig_threshold', 'comment', ...
			'(V), threshold for starting a ringdown record');
			addObjProp(Hdr, this, 'record_time', 'comment', '(s)');
			addObjProp(Hdr, this, 'n_avg', 'comment', ...
			'Number of ringdowns to be averaged');
			addObjProp(Hdr, this, 'downsampled_rate', 'comment', ...
			['(samples/s), rate to which a ringown trace is ', ...
			'downsampled with averaging after acquisition']);
			addObjProp(Hdr, this, 'auto_save', 'comment', '(s)');

			% Adaptive measurement oscillator
			addObjProp(Hdr, this, 'adaptive_meas_osc', 'comment', ...
			['If true the measurement oscillator frequency is ', ...
			'adjusted during ringdown']);
			addObjProp(Hdr, this, 'ad_osc_margin');
			addObjProp(Hdr, this, 'fft_length', 'comment', '(points)');

			% Timer poll parameters
			addParam(Hdr, this.name, 'poll_period', ...
			this.PollTimer.Period, 'comment', '(s)');
			addObjProp(Hdr, this, 'poll_duration', 'comment', '(s)');
			addObjProp(Hdr, this, 'poll_timeout', 'comment', '(ms)');
			end
			end

			%% Set and get methods.
			methods

			function freq=get.drive_osc_freq(this)
			path=sprintf('/%s/oscs/%i/freq', this.dev_id, this.drive_osc-1);
			freq=ziDAQ('getDouble', path);
			end

			function set.drive_osc_freq(this, val)
			assert(isfloat(val), ...
			'Oscillator frequency must be a floating point number')
			path=sprintf('/%s/oscs/%i/freq', this.dev_id, this.drive_osc-1);
			ziDAQ('setDouble', path, val);
			notify(this,'NewSetting');
			end

			function freq=get.meas_osc_freq(this)
			path=sprintf('/%s/oscs/%i/freq', this.dev_id, this.meas_osc-1);
			freq=ziDAQ('getDouble', path);
			end

			function set.meas_osc_freq(this, val)
			assert(isfloat(val), ...
			'Oscillator frequency must be a floating point number')
			path=sprintf('/%s/oscs/%i/freq', this.dev_id, this.meas_osc-1);
			ziDAQ('setDouble', path, val);
			notify(this,'NewSetting');
			end

			function set.drive_on(this, val)
			path=sprintf('/%s/sigouts/%i/on',this.dev_id,this.drive_out-1);
			% Use double() to convert from logical type
			ziDAQ('setInt', path, double(val));
			notify(this,'NewSetting');
			end

			function bool=get.drive_on(this)
			path=sprintf('/%s/sigouts/%i/on',this.dev_id,this.drive_out-1);
			bool=logical(ziDAQ('getInt', path));
			end

			function set.current_osc(this, val)
			assert((val==this.drive_osc) \|\| (val==this.meas_osc), ...
			['The number of current oscillator must be that of ', ...
			'the drive or measurement oscillator, not ', num2str(val)])
			ziDAQ('setInt', [this.demod_path,'/oscselect'], val-1);
			notify(this,'NewSetting')
			end

			function osc_num=get.current_osc(this)
			osc_num=double(ziDAQ('getInt', ...
			[this.demod_path,'/oscselect']))+1;
			end

			function amp=get.drive_amp(this)
			path=sprintf('/%s/sigouts/%i/amplitudes/%i', ...
			this.dev_id, this.drive_out-1, this.drive_osc-1);
			amp=ziDAQ('getDouble', path);
			end

			function set.drive_amp(this, val)
			path=sprintf('/%s/sigouts/%i/amplitudes/%i', ...
			this.dev_id, this.drive_out-1, this.drive_osc-1);
			ziDAQ('setDouble', path, val);
			notify(this,'NewSetting');
			end

			function set.lowpass_order(this, val)
			assert(any(val==[1,2,3,4,5,6,7,8]), ['Low-pass filter ', ...
			'order must be an integer between 1 and 8'])
			ziDAQ('setInt', [this.demod_path,'/order'], val);
			notify(this,'NewSetting');
			end

			function n=get.lowpass_order(this)
			n=ziDAQ('getInt', [this.demod_path,'/order']);
			end

			function bw=get.lowpass_bw(this)
			tc=ziDAQ('getDouble', [this.demod_path,'/timeconstant']);
			bw=ziBW2TC(tc, this.lowpass_order);
			end

			function set.lowpass_bw(this, val)
			tc=ziBW2TC(val, this.lowpass_order);
			ziDAQ('setDouble', [this.demod_path,'/timeconstant'], tc);
			notify(this,'NewSetting');
			end

			function rate=get.demod_rate(this)
			rate=ziDAQ('getDouble', [this.demod_path,'/rate']);
			end

			function set.demod_rate(this, val)
			ziDAQ('setDouble', [this.demod_path,'/rate'], val);
			notify(this,'NewSetting');
			end

			function set.downsample_n(this, val)
			n=round(val);
			assert(n>=1, ['Number of points for trace averaging must ', ...
			'be greater than 1'])
			this.downsample_n=n;
			notify(this,'NewSetting');
			end

			function set.aux_out_on(this, bool)
			path=sprintf('/%s/auxouts/%i/offset', ...
			this.dev_id, this.aux_out-1);
			if bool
			out_offset=this.aux_out_on_lev;
			else
			out_offset=this.aux_out_off_lev;
			end
			ziDAQ('setDouble', path, out_offset);
			notify(this,'NewSetting');
			end

			function bool=get.aux_out_on(this)
			path=sprintf('/%s/auxouts/%i/offset', ...
			this.dev_id, this.aux_out-1);
			val=ziDAQ('getDouble', path);
			% Signal from the auxiliary output is continuous, we make the
			% binary decision about the output state depending on if
			% the signal is closer to the ON or OFF level
			bool=(abs(val-this.aux_out_on_lev) < ...
			abs(val-this.aux_out_off_lev));
			end

			function set.downsampled_rate(this, val)
			dr=this.demod_rate;
			if val>dr
			% Downsampled rate should not exceed the data transfer rate
			val=dr;
			end
			% Round so that the averaging is done over an integer number of
			% points
			this.downsample_n=round(dr/val);
			notify(this,'NewSetting');
			end

			function val=get.downsampled_rate(this)
			val=this.demod_rate/this.downsample_n;
			end

			function set.fft_length(this, val)
			if val<1
			val=1;
			end
			% Round val to the nearest 2^n to make the calculation of
			% Fourier transform efficient
			n=round(log2(val));
			this.fft_length=2^n;
			notify(this,'NewSetting');
			end

			function val=get.fft_rbw(this)
			val=this.demod_rate/this.fft_length;
			end

			function set.fft_rbw(this, val)
			assert(val>0,'FFT resolution bandwidth must be greater than 0')
			% Rounding of fft_length to the nearest integer is handled by
			% its own set method
			this.fft_length=this.demod_rate/val;
			notify(this,'NewSetting');
			end

			function set.n_avg(this, val)
			this.AvgTrace.n_avg=val;
			notify(this,'NewSetting');
			end

			function val=get.n_avg(this)
			val=this.AvgTrace.n_avg;
			end

			function val=get.avg_count(this)
			val=this.AvgTrace.avg_count;
			end

			function set.aux_out_on_t(this, val)
			assert(val>0.001, ...
			'Aux out on time must be greater than 0.001 s.')
			this.aux_out_on_t=val;
			notify(this,'NewSetting');
			end

			function set.aux_out_off_t(this, val)
			assert(val>0.001, ...
			'Aux out off time must be greater than 0.001 s.')
			this.aux_out_off_t=val;
			notify(this,'NewSetting');
			end

			function set.enable_acq(this, val)
			this.enable_acq=logical(val);
			notify(this,'NewSetting');
			end
			end
			end

rINSTCONTROL/@MyZiRingdown/MyZiRingdown.m43180a46f866TekRSA-Freq-vs-Time

MyZiRingdown.mView Options

rINSTCONTROL/@MyZiRingdown/MyZiRingdown.m
43180a46f866TekRSA-Freq-vs-Time

MyZiRingdown.m
View Options