Figure 7 shows an IO Data model to demonstrate the basic principle of the relationships of the Objects in the PROFINET Aspect with the Objects and Variables representing IO Data in the Functional Aspect of the Information Model.
Figure 7 – IO Data Organization
The “Submodule 1” Object in the PROFINET Aspect relates to the GsdGenSubmoduleApplicationType Object using a 0:RepresentsSameFunctionalityAs ReferenceType. The GsdGenIoDataItemVariableType Variables relate to the Signal Objects representing IO Data in the PROFINET Aspect using a 0:RepresentsSameEntityAs ReferenceType.
Figure 8 shows the XML schema of the “Input” XML elements in the GSDML. The “Output” element has the same layout. The optional “Channel” elements specify the partition of the IO Data into individual IO Channels, see 6.4 for details.
Figure 8 – XML Schema of Input and Output elements in GSDML
The IO Data is described using “DataItem” elements. In particular, the “DataItem” elements define the data types used and therefore together determine the size and layout of the memory allocated for IO Data (see [GSDML], 8.12 for a thorough description). Figure 9 shows the XML schema of the “DataItem” XML element.
Figure 9 – XML Schema of DataItem elements in GSDML
If the “DataType” attribute describes an unsigned numeric data type or an “OctetString”, the optional “UseAsBits” attribute may be present and set to “true” (see description of “UseAsBits” attribute in [GSDML], 8 ff.). The optional “BitDataItem” elements are present in this case and the definition of individual bits inside the DataItem data type.
If the “Subordinate” attribute is present (only allowed for “Input/DataItem” elements) and set to “true”, the IO Data of the Submodule must be organized according to rules defined by RIOforFA (see [RIO FA]).
Figure 10 – Mapping of XML elements describing IO Data
Figure 10 shows the mapping of the XML elements describing the IO Data to the representing Objects and Variables in the Information Model.
The GsdGenIoDataType represents the mapping of the content of the GSDML “Input” and “Output” child elements of the “IOData” element. For a detailed description see 7.2 and 9.1.