pecial parameters 5.3.4.4 Observer MSCs generate feed commands When an MSC is compiled with an SDL model, the inputs coming from the environment in the MSC are automatically translated into feed commands in the simulation. For example, in Figure 5.67, if the MSC test4 is compiled with the SDL model test2, after launching the Simulator you will see the following feed already set: > list feed feed chl sig2 ( -8, true) feed chl sig2 ( 45, false) This feature saves time when using MSCs to test an SDL model. Automatic Observation of Simulations 155 system test2 test4 my_BTS sig2(45, False) NEWTYPE colors LITERALS cyan, magenta, yellow, black ; sig2( -8, True) ENDNEWTYPE; SIGNAL sig( 4.. .16, cyan, False) sig (Integer, colors, Boolean) , sig2 (Integer, Boolean) ; Figure 5.67 MSC test4 observing the SDL model test2 5.3.4.5 The MSC attributes search and verify According to the kind of properties you want to check and the kind of SDL model you use, you can select one of the following MSC attributes for the simulation (which are an MSC extension specific to ObjectGeode): search: detects behaviors conforming to the MSC verify16: like search, plus detects behaviors nonconforming to the MSC. Generally, it is better to use verify because the Simulator will not only detect if your model conforms to the MSC but will also indicate when it encounters errors17. However, there are some subtle differences that we will illustrate in the following lines. To change the attributes of an MSC, load it into the Editor, select it and do Edit > MSC Simulation Properties: the window shown in Figure 5.68 appears. The last three choices in the Goal part (Complete test purpose.. ) are reserved for Test Composer, the test case generator. Figure 5.69 shows the simulation results with the basic observer MSC test_seq. It expects output of signals sA, sB and sC. If we set the simulation attribute of the MSC observer to search: the first occurrence sequence of sA, sB, sC is detected as a success; the two consecutive sA, sA do not provoke any error; the