State Machine Specifications(2 Can easily define time constraints on transitions e.g. telephone switch, must dial 4 digits (internal call) within 10 seconds P offhook Start Timer T(10) Idle Dialtone Await first digit P depress hookswitch 1 thru 8/ Start Timer T(10) Alarm/ Reordertone/Await second digit Alarm T Dia Reordertone o thru 9/- Again Alarm T Await third Reordertone digit Conversing Alarm T o thru 9/- Reordertone Await fourth y o thru 9/ digit Connectc Copyright Nancy Leveson, Sept. 1999 State Machine Specifications (2) Can easily define time constraints on transitions: e.g. telephone switch, must dial 4 digits (internal call) within 10 seconds P offhook / Start Timer T (10), Dialtone Alarm T / Reordertone Alarm T / Reordertone Alarm T / Reordertone Alarm T / Reordertone Start Timer T (10) P depress hookswitch / Idle Again Dial Await first digit Await second digit Await fourth digit Await third digit Conversing 0 thru 9 / Connect 0 thru 9 / - 0 thru 9 / - 1 thru 8 / - ✁