I have some custom models in my simulation. When I run simulation I get the following error message: No true transitions from state (<state_name>), T (<time>), EV (<event_id>), MOD (module_name), PROC (sim_pro_err_transit). What can I do?

I have some custom models in my simulation. When I run simulation I get the following error message: No true transitions from state (<state_name>), T (<time>), EV (<event_id>), MOD (module_name), PROC (sim_pro_err_transit). What can I do?

In a process model (or any Finite State Machine) a transition is made from one state to other based on an event. So it is necessary that, when an event happens, the current state of the process model has one and only one true (or valid) transition. This particular error suggests that a process model housed in module module_name is recieving an interrupt when the process is in the state_name state, that is not handled by that state. As a result it cannot transit from that state to any other state, causing the simulation to terminate.To debug this issue OPNET debugger (odb) will have to used. This will help determining the which event is the source of this interrupt and what kind of interrupt it is. For starters, use the 'evstop' command in ODB to stop at the event where this problem occurs, then use 'fulltrace' and 'cont' to follow the flow of what happens. Following are good references on how to use odb for for details on how to use odb for debugging such problems,a. FAQ#500b. Online Documentation (Chapter Simulation Execution under External Interfaces menu)c. OPNETWORK Presentations (Sessions 1502 and 1503)Once the source of this event and type of this interrupt is known, it needs to be determined whether or not this is something expected or not, meaning is it right behavior that needs to be modeled or not. Depending on the cause following actions needs to be taken:1. This is intended interrupt and which is not handled till yet.Action: Support for handling the interrupt needs to be introduced in the process model recieving this interrupt.2. This is intented interrupt, but needs to be ignored.Action: Add a default transition to the state back to itself. This is not the best modeling practice, since the process model is getting interrupts which it does not really care about, but may be inevitable interfacing with other models.3. This is unintended interrupt.Action: Change the behavior of the source of the source of this event. This condition is similar to #2 but here you have control over (for modification) the source of the interrupt and it is incorrect modeling at the source which is causing this interrupt and hence this error.

DES Kernel->Error Messages/Logs,DES Kernel->Process Modeling/Coding