Add ExtendedCall to PLCObject as a replacement of RemoteExec and reflect it in eRPC interface.
ExtendedCall is a generic remote procedure call that runtime code can register to and that IDE extensions can call.
For example a fieldbus extension can use ExtendedCall to browse the fieldbus devices connected to the runtime.
Widget syntax
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.. highlight:: text
HMI elements are SVG elements whose labels start with ``HMI:``::
HMI:WidgetType[|freq][[:param]...][[@a=path[,min][,max]]...][#expression]
Widget Type
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Update Frequency
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Parameters
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Variable bindings
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Enable expression
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