Why an event-driven model?
Any execution control strategy (cyclic, time scheduled, etc.) can be represented in terms of an event-driven model, but the converse is not necessarily true. IEC 61499 opts for the more general model in order to provide maximum flexibility and descriptive power to compliant standards and systems. • How can a change in a data value generate an event? E_R_TRIG and E_F_TRIG function block types are defined in Annex A of IEC 61499-1 which propagate an input event when the value of a Boolean input rises or falls, respectively, between successive occurrences of the input event. Instances of this type may be combined with with other function blocks to produce rising- and falling-edge triggers, threshold detection events, etc. • What are event types? What are they used for? An event type is an identifier associated with an event input or an event output of a function block type, assigned as part of the event input or output declaration, as described in IEC 61499-1-2.2.1.1. It can be used by so
