xPC Target

Signal Tracing with MATLAB

Creating a scope object allows you to select and view signals using the scope methods. This section describes how to signal trace using xPC Target functions instead of using the xPC Target graphical user interface.

After you create and download the target application, you can view output signals. This procedure uses the Simulink model xpcosc.mdl as an example, and assumes you have build the target application for this model.

1. Start running your target application. Type either

• +tg or tg.start or start(tg)
  

1. The target PC displays the following message.

   • System: execution started (sample time: 0.0000250)
     

2. To get a list of signals, type either

• set(tg, 'ShowSignals', 'on') 
  

1. or type

   • tg.ShowSignals='on'
     

   The MATLAB window displays a list of the target objects properties for the available signals. For example, the signals for the model xpcosc.mdl are shown below.

   • ShowSignals = On
        Signals = PROP.   VALUE             BLOCK NAME
                  S0      0.000000          Integrator1
                  S1      0.000000          Signal Generator
                  S2      0.000000          Gain      
                  S3      0.000000          Integrator
                  S4      0.000000          Gain1     
                  S5      0.000000          Gain2     
                  S6      0.000000          Sum       
     

   The signal names (S0, S1 . . .S6) are properties of the target object. For more information, see Signal Monitoring with MATLAB.

3. Create a scope to display on the target PC. For example, to create a scope with an identifier of 1 and a scope object name of sc1, type

• sc1=tg.addscope('target', 1) or sc1=addscope(tg, 'target', 1)
  

4. List the properties of the scope object. For example, to list the properties of the scope object sc1, type

• sc1
  

1. The MATLAB window displays a list of the scope object properties. Notice the scope properties StartTime, Time, and Data are not accessible with a scope of type target.

   • xPC Scope Object
        Application          = xpcosc
        ScopeId              = 1
        Status               = Interrupted
        Type                 = Target
        NumSamples           = 250
        Decimation           = 1
        TriggerMode          = FreeRun
        TriggerSignal        = -1
        TriggerSample        = -1
        TriggerLevel         = 0
        TriggerSlope         = Either
        TriggerScope         = 1
        Mode                 = Redraw (Graphical)
        YLimit               = Auto
        Grid                 = On
        StartTime            = Not accessible
        Data                 = Not accessible
        Time                 = Not accessible
        Signals              = no Signals defined
     

5. Add signals to the scope object. For example, to add Integrator1 and Signal Generator, type

• sc1.addsignal ([0,1]) or addsignal(sc1,[0,1])
  

1. The target PC displays the following messages.

   • Scope: 1, signal 0 added
     Scope: 1, signal 1 added
     

   After you add signals to a scope object, the signals are not shown on the target screen until you start the scope.

6. Start the scope. For example, to start the scope sc1, type either

• +sc1 or sc.start or start(sc1) 
  

1. The target screen plots the signals after collecting each data package. During this time you can observe the behavior of the signals while the scope is running.

7. Stop the scope. Type either

• sc1 or sc1.stop or stop(sc1)
  

1. The signals shown on the target PC stop updating while the target application continues running, and the target PC displays the following message.

   • Scope: 1, set to state 'interrupted'
     

Signal Tracing with xPC Target Remote Control Tool

Signal Tracing with xPC Target Scope Blocks