MATLAB Examples

Switching between Harness Configurations

Change test harness settings for different verification objectives.


This example shows how to change between various harness settings during incremental component development. The example model counts the number of ticks and outputs the count.

mdl = 'sltestSwitchHarnessConfigurationExample';

Open the test harness Counter_harness attached to the Counter subsystem. This test harness has been created for prototyping by setting the CreateWithoutCompile parameter to true and the SynchronizationMode parameter to Synchronize on harness open and close. The harness has been generated without compiling the model, and is configured to synchronize changes between the main model and harness during harness open and close. Open the test harness.[mdl '/Counter'],'Counter_harness');

The test harness Counter_harness is not configured for the correct datatypes used in the main model. This can cause simulation errors. Rebuild the test harness to ensure that the datatypes used in the test harness are the same as that used in the main model.

Click the test harness badge in the test harness window. This opens the test harness properties dialog. Set these properties:

  • Synchronization Mode: Synchronize on harness open

Click OK. The properties take effect the next time you open the test harness.

To manually rebuild the test harness select Analysis > Test Harness > Rebuild Harness from Main Model or enter:

sltest.harness.set([mdl '/Counter'],'Counter_harness','RebuildWithoutCompile',false);
sltest.harness.rebuild([mdl '/Counter'],'Counter_harness');

The test harness now simulates without errors. To rebuild each time you open the model, update the Rebuild harness on open setting in the dialog or enter:

sltest.harness.set([mdl '/Counter'],'Counter_harness','RebuildOnOpen',true);

Close the test harness.

sltest.harness.close([mdl '/Counter'],'Counter_harness');

The counter modeled in the component under test can be reset with an external signal. Enter the following commands to create reset logic in the model.

delete_line([mdl,'/Counter'],'Previous Output/1','Add/2');
h1 = add_block('simulink/Sources/In1',[mdl,'/Counter/reset']);
set_param(h1,'Position',[65   148    95   162]);
h2 = add_block('built-in/Constant',[mdl,'/Counter/C1']);
set_param(h2,'Position',[40    86   120   114]);
h3 = add_block('simulink/Signal Routing/Switch',[mdl,'/Counter/Switch']);
set_param(h3,'Position',[185    91   205   139]);
add_line([mdl,'/Counter'],'Previous Output/1','Switch/3','autorouting','on');
clear h1 h2 h3;

Enter the following commands to connect the inputs of the Counter subsystem to a root-level Inport.

h4 = add_block('simulink/Sources/In1',[mdl,'/reset']);
set_param(h4,'Position',[50   305    70   325]);
set_param([mdl,'/ticks_to_count'],'Position',[50   250    70   270]);
set_param([mdl,'/ticks_to_count'],'Position',[50   250    70   270]);
set_param([mdl,'/count'],'Position',[480   280   500   300]);
clear h4;

Load external data to the model with the following commands:

set_param(mdl,'ExternalInput','ticks_to_count, reset');

Open the test harness. Notice that the conversion subsystems are rebuilt.[mdl '/Counter'],'Counter_harness');

Add a Pulse Generator block to drive the Counter reset port.

h5 = add_block(sprintf('simulink/Sources/Repeating\nSequence Stair'),'Counter_harness/Reset');
set_param(h5,'Position',[230   240   260   270]);
set_param(h5,'OutValues','[1 0 1 0]');
clear h5;

The test harness simulates without any errors or warnings.



sltest.harness.close([mdl '/Counter'],'Counter_harness');
close_system(mdl, 0);
clear mdl logsOut;