nications Systems with SDL Loop: loop in the states graph. MaxQueueLength: the maximum number of signals allowed in a process input queue has been exceeded. MaxTransLen: infinite loop within a transition. MSCVerification: the MSC has been verified (the simulated behavior matches the MSC). MSCViolation: the MSC has been violated. Observer: an observer process has not been able to execute a transition. Operator: error in an SDL predefined operator. Optional: error in an ASN.1 optional field. Output: error in an output. PowerWalk: reports used for MSC and TTCN test cases generation (Autolink). RefError: concerns SDL models using pointers (an extension provided by Tau). Subrange: range overflow in a syntype value. TreeWalk: reports used for MSC and TTCN test cases generation (Autolink). UnionTag: error in an ASN.1 union. UserRule: a user-defined rule is satisfied. UserSpecified: not found in the Validator documentation. View: error in view-revealed. 8.1.9.10 MSC verification options Search depth: 1000: the maximum exploration depth (number of transitions) executed to verify an MSC. When the depth is reached, the Validator backtracks and explores other transitions, if any. Search mode: Violation: after trying this option, its effect has not been found. Algorithm: BitState: by default, a bit-state exploration is performed to try to verify the MSC. The other alternative is TreeSearch. Ignore parameters: Off: if set to On, MSC parameters are ignored. 8.1.9.11 Other options Report viewer autopopup: On: the Report Viewer will automatically appear after the end of the Validation. MSC trace autopopup: On: the MSC Editor will automatically appear. MSC trace states: On: the state of SDL processes is written in the MSC trace. Other Simulator Features 279 MSC trace actions: Off: the actions (tasks etc.) executed are written in the MSC trace. MSC trace channels: Off: the env instance is not split into one instance for each channel connected to env in the MSC trace. 8.2 OBJECTGEODE 8.2.1 Writing in the Simulator trace To write a m