Definition of NSA-DEVS
- Basic ideas of NSA-DEVS:
- based on RPDEVS, i.e.
- only one transition function δ(s, x)
- only one output function λ(s, x)
- state transition times always >
0, may be infinitesimal
- each component has an input delay τ > 0, generally
infinitesimal
- behaviour
- external event at t → call of λ and δ at t + τ
- internal event at t → call of λ and δ at t
- strict Mealy-type behaviour impossible
- Delay times:
- lots of additional parameters
- τ = ε should work almost always (hopefully)
- "transient states" have delay ε mostly (hopefully)
- finetuning of infinitesimal delays
- sometimes necessary (e.g. for singleserver)
- can be used to order "concurrent" events
explicitely
- NSA-DEVS simulator:
- uses defaults value τ = ε
- standard behaviour
- shows state change and output values only at the
end of an infinitesimal episode
- debugging behaviour
- user supplies a finite value for ε
- behaviour at infinitesimal scale
becomes visible