GSPN Templates and Interface Places Sample Clauses

GSPN Templates and Interface Places. Recall the idea of the translation as outlined in Fig. 2. We start by introducing the set IF of interface places: IF = {Failedv, Unavailv, Activev | v ∈ F} ∪ {Disabledv | v ∈ FBE} The places F manage the communication for the different mechanisms in a DFT. A token is placed in Failedv once the corresponding DFT gate v fails. On the failure of a gate, the tokens in the failed places of its children are not removed as a child may have multiple parents. Inhibitor arcs connected to Failedv prevent the repeated failure of an already failed gate. The Unavailv places are used for the claiming mechanism of SPAREs, Activev manages the activation of spare components, while Disabledv is used for SEQs. Every DFT node is translated into some auxiliary places, transitions, and arcs. The arcs either connect interface or auxiliary places with the transitions. For each node-type, we define a template that describes how a node of this type is translated into a GSPN (fragment). → { | ∈ F} To translate contextual behaviour of the node, we use priority variables π = πv v . Transition priorities are functions over the priority variables π, i.e., Π : T N[π]. These variables are instantiated with concrete values in Sect. 4, yielding priorities in N. This section does not exploit the partitioning of the immediate transitions; the usage of this GSPN ingredient is deferred to Sect. 4. Put differently, for the moment it suffices to let each immediate transition constitute its (xxxxxxxxx) partition.