This example shows how to trace a signal using a software triggered xPC Target™ host scope. After the script builds and downloads the oscillator model, xpcosc, to the target computer, it adds a scope of type 'host' to the target application and the signals 'Integrator1' and 'Signal Generator' to the scope. The scope is then configured in the software trigger mode.
Once the trigger is initiated, the scope is monitored to determine when its data acquisition is complete. Next, the scope data is uploaded to the host computer and plotted. This process repeats 25 times. The software trigger is re-enabled each run after a random pause (between 0 and 4 seconds). After every fifth run, the damping gain 'Gain1/Gain' is set to a new random value (between 0 and 2000).
Use 'xpctargetping' to test for a proper host-target connection.
if ~strcmp(xpctargetping, 'success') error(message('xPCTarget:examples:Connection')); end
Open the oscillator model, xpcosc. Under the model's configuration parameter xPC Target option settings, the system target file has been set to xpctarget.tlc. Hence, building the model will create an executable image, xpcosc.dlm, that can be run on a PC booted with the xPC Target kernel.
Build the model and download the image, xpcosc.dlm, to the target computer.
set_param('xpcosc','RTWVerbose','off'); % Configure for a non-Verbose build. rtwbuild('xpcosc'); % Build and download application.
### Starting xPC Target build procedure for model: xpcosc ### Generated code for 'xpcosc' is up to date because no structural, parameter or code replacement library changes were found. ### Successful completion of build procedure for model: xpcosc ### Looking for target: TargetPC1 ### Download model onto target: TargetPC1
Create the MATLAB variable, tg, containing the xPC Target Object. This object contains all information needed to communicate with and control the target computer.
tg = xpc; % Create an xPC Target Object tg.SampleTime = 0.000250; % Set sample time to 250us tg.StopTime = 10000; % Set stop time to a high value (10000s) start(tg); % Start model execution
Create, configure, and plot to the host scope during each run.
tPar = getparamid(tg, 'Gain1', 'Gain'); % Get indx of parameter 'Gain1/Gain' signals(1) = getsignalid(tg, 'Integrator1'); % Get indx of signal 'Integrator1' signals(2) = getsignalid(tg, 'Signal Generator'); % Get indx of signal 'Signal Generator' sc = addscope(tg, 'host'); % Define (add) a host scope object addsignal(sc, signals); % Add signals to signal list of scope object sc.NumSamples = 200; % Set number of samples sc.Decimation = 4; % Set decimation factor sc.TriggerMode ='Software'; % Set trigger mode figh = findobj('Name', 'scsoftwaredemo');% Does the plot figure exist? if isempty(figh) figh = figure; % No: Create figure set(figh, 'Name', 'scsoftwaredemo', 'NumberTitle', 'off'); else figure(figh); % Yes: Make it the current figure end % Loop to acquire 25 data packages from the scope object. m = 1; flag = 0; for n = 1 : 25 if isempty(find(get(0, 'Children') == figh, 1)), flag = 1; break; end % Change parameter Gain1/Gain every fifth acquisition loop % to a random value between 0 and 2000. if ~m setparam(tg, tPar, 2*1000*rand); end m = rem(m + 1, 5); start(sc); % Start scope object % Wait until scope object has 'ready' state. while ~strcmp(sc.Status, 'Ready for being Triggered'), end % Randomize the amount of wait time before triggering scope. % Wait a random period (0..4s). ttrigger = rand * 4; title(['scsoftwaredemo: ', num2str(n), ... ' of 25 data packages, will be triggered in ', ... num2str(ttrigger), 's']); pause(ttrigger); if isempty(find(get(0, 'Children') == figh, 1)), flag = 1; break; end % Software trigger the scope object. trigger(sc); % Wait until scope-object has 'finished' state. while ~strcmpi(sc.Status,'finished'); end % Create time vector, upload scope data and display it. t = sc.Time; % Upload time vector plot(t, sc.Data); % Upload acquired data and plot set(gca, 'XLim', [t(1), t(end)], 'YLim', [-10, 10]); drawnow; end if ~flag, title('scsoftwaredemo: finished'); end
When done, stop the application and close the model.
stop(tg); % Stop model close_system('xpcosc',0); % Close model % EOF scsoftwaredemo.m