Figure 11 shows the “IO Data” Sub-Aspect in the Functional Aspect of the Information Model.


Figure 11 – IO Channel Organization

The GsdGenIoDataType Objects relate to the associated GsdGenIoChannelType Objects using the 0:HasComponent ReferenceType. The “Data” components of the GsdGenIoChannelType Objects relate to the data item elements representing the channel data using 0:AssociatedWith ReferenceTypes. The optional “Quality” component relates to the data item representing the part of the IO Data which contains the qualifier information of the respective channel. The “Data” components of the “OutputChannel1” and “OutputChannel2” Objects refer to the same data item (“Data Item 1”).

image016.jpgFigure 12 shows the “Channel” elements schema organization in the GSDML.

Figure 12 – XML Schema of Channel elements in GSDML

Each channel specified has a unique channel number defined by the “Number” attribute. The mandatory “Data” element’s attribute “BitOffset” (not shown in the figure) specifies an offset into the “DataItem” / “BitDataItem” elements and points to the start of the channel data. The channel data may be defined by a single “DataItem” element or by a sequence of consecutive “DataItem” elements. The BitOffset may point into a data item also (see channel “Data” element specification in [GSDML], 8 ff.). The mandatory “BitLength” attribute specifies the length of the channel data.

Figure 13 shows the mapping of the “Channel” elements and its child elements to Objects in the Information Model.


Figure 13 – Mapping of XML elements describing Channel Data

The BitOffset Property of the optional “Quality” Object points to the start of the channel quality data. This offset into the data may point into a data item also (no separate data item for quality information, see channel “Quality” element specification in [GSDML] chapter 8 ff.). The “Data” and the “Quality” components of the GsdGenIoChannelType Object are associated with the same data item using 0:AssociatedWith ReferenceTypes in this case.

The ”Format” Property defines the size and layout of the quality information (see “Quality” element specification in [GSDML], 8 ff.).