Are extensible user-defined function blocks permitted?
IEC 61499 follows the usage of IEC 61131-3 and does not define a mechanism for specification of extensible inputs and outputs of user-defined function blocks. The use of the ellipsis (…) and accompanying textual descriptions is considered adequate for the specification of extensible inputs and outputs of standard function blocks in IEC 61499. • Can alternative graphical representations be used? Software tools can use alternative graphical, textual or tabular representations, so long as accompanying documentation specifies an unambiguous mapping to the graphical elements and associated textual syntax defined in IEC 61499-1. • How can a function block respond to faults and exceptions? In the IEC 61499 model, faults and exceptions are modeled as event outputs and associated data outputs of service interface function blocks. These outputs can be connected to appropriate event inputs and associated data inputs of any function blocks which must respond to the fault or exception, e.g., by c
