rameter of signal L_EstabReq (the number of the DLC to establish) to check that it is equal to the DLC number transmitted in L_EstabConf. /* Probe on block DLCa: */ probe DLC_ a v76test!DLCa; observer obs1 wait4conf it:= INPUT L_EstabReq TO DLC_a it:= OUTPUT L_EstabConf FROM DLC a We store the After the output, DLC_num:= it L_EstabReq ! p1 we check that parameter of it t!L EstabConf ! p1 __EstabReq the parameter into DLC_nur of L EstabConf ( DLC_num is the same as SUCCESS STATE ok; the parameter Now we wait ERROR STATE bad; wait4conf for L EstabConf of _EstabReq DLC_num Integer; Figure 5.3 Example of GOAL observer The observation principles described here are available in any simulation mode: interactive, random or exhaustive, plus their variants. In exhaustive simulation, the simulators provide a way to replay interactively the scenarios leading to the satisfaction or to the violation of a property. 5.1.2 Specificity of observation with MSCs in Tau SDL Suite In Tau SDL Suite Validator², the observation of properties using MSCs or HMSC is different compared to ObjectGeode. In Tau SDL Suite Validator: Only one MSC (or HMSC) at a time can be used as an observer (i.e. can be loaded by the command Load-MSC). To use several MSCs, they can be grouped into an HMSC. The MSC (or HMSC) does not have to be compiled with the SDL model. As explained in Section 5.2.5.1, Tau observes any signals, as opposed to ObjectGeode that observes only signals present in the observer MSC, by default. More important, the MSC (or HMSC) drives the exploration, as a TTCN test case when testing an IUT (Implementation Under Test): considering the MSC in Figure 5.4, Tau Validator will not transmit sigB before sigA to the SDL model. In ObjectGeode, the same MSC would generate two feed sigA and sigB, and sigB could be transmitted first to the SDL model (if ready to input it). This is why in general Tau Validator checks MSCs faster than ObjectGeode. To speed up the MSC verification in ObjectGeode, you must set the MSC Simulation Property 2 Note that