xPC Target

Parameter Tuning with MATLAB Commands

You use the MATLAB functions to change block parameters. With these functions you do not need to set Simulink in external mode, and you do not need to connect Simulink with the target application.

You can download parameters to the target application while it is running or between runs. This feature lets you change parameters in your application without rebuilding the Simulink model.

After you download a target application to the target PC, you can change block parameters using MATLAB functions. This procedure uses the Simulink model xpcosc.mdl as an example, and assumes you have created and downloaded the target application for that model.

1. In the MATLAB window, type either

+tg or tg.start or start(tg)

The target PC displays the following message.

System: execution started (sample time: 0.001000)

2. Display a list of parameters. Type either

set(tg,'ShowParameters','on') or tg.ShowParameters='on'

and then type

tg

The MATLAB window displays a list of the target objects properties.

ShowParameters = On
Parameters= PROP VALUE     PARAMETER NAME    BLOCK NAME
            P0   0.000000  InitialCondition  Integrator1
            P1   4.000000  Amplitude         Signal Generator
            P2   20.000000 Frequency         Signal Generator
            P3   1000000.0 Gain              Gain
            P4   0.000000  InitialCondition  Integrator
            P5   400.00000 GainGain1
            P6   1000000.0 GainGain2

The parameter names (P0, P1, . . .P6) are properties of the target object. and the signal names (S0,S1, . . .) are also properties of the target object.

3. Change the gain. For example, to change the Gain1 block, type either

tg.p5=800 or set(tg,'p5',800)

As soon as you change parameters, the changed parameters in the target object are downloaded to the target application. The target PC displays the following message.

Param: param 5 updated

And the plot frame updates the signals after running the simulation with the new parameters.

4. Stop the target application. In the MATLAB window, type either

-tg or tg.stope or stop(tg)

The target application on the target PC stops running, and the target PC displays the following messages.

System: execution stopped
minimal TET: 0.000023 at time 1313.789000
maximal TET: 0.000034 at time 407.956000

Parameter Tuning

Parameter Tuning with Simulink External Mode