Limits and troubleshooting¶

Not available yet¶

• Composite states (superstates holding a sub-machine) and transitions leaving a composite state.
• Parallel regions (orthogonal states), fork / join.
• History (H, H*), junction, entry / exit points.
• Internal events, send, internal transitions.
• Text on the links: OMEdit cannot show the parameters of a transition on a connection line; the transition is therefore a block placed on the arrow.
• Structure checks: nothing prevents placing two Initials, or connecting the same port twice.

Troubleshooting¶

"maximum number of event iterations" or simulation stuck at one instant. Transitions that can always fire form a loop: for instance a round trip off → on → off whose two transitions are completions with guards true at the same time. The machine fires endlessly at the same instant. Remedies: a Signal or When trigger (events, fired once), exclusive guards (hysteresis: T < 19 °C on one side, T > 21 °C on the other), or an after.

A transition never fires. Check that source is connected to the state it leaves and target to the state it enters (the arrowhead must point to the target); that no transition of higher priority fires instead; that a Signal or When event does occur while the source state is active and the guard is true at that instant.

Fewer equations than variables ("under-determined system"). A port of a state is not connected to any transition: nTop, nRight, nBottom or nLeft is larger than the number of transitions actually connected on that side (for instance after deleting a connection). Check Model then counts fewer equations than variables, and the simulation fails. Set the right number back in the Ports tab of the parameter dialog of the state.

Too many equations ("over-determined system"). Both ends of a transition (or two transitions) are connected to the same port element. Each end of a transition needs its own element: for a transition from a state to itself, use two ports, for instance bottom[1] and bottom[2].