Structure Compose

Operator Menu Location: Structures

Operator Bitmap:

Functional Description:
A structure groups data for sharing with other schema layers or modules. The Compose operator creates a package of data based on the structure definitions in a Fairmount Automation xml extension, which must be linked to a Logical Network, Schema, Hardware Interface File or Workspace. The pin determines when the Structure inputs are read. If it is not present, the inputs are read on each execution cycle. The Structure Compose operator stores a group of signal values input on the boolean, float or structure pins that can change during schema execution. For instance, it may store a system set-point tuning parameter and the resulting output that a plant operator or design engineer may wish to modify and monitor at runtime. The pins which appear on a Structure Variable operator depend upon which structure definition the operator is linked to in its Structure property. In the example XML file below, the set point and temperature fields are part of the Controller_Struct structure.

The designer next does one of three things to link this definition to a Structure Compose operator :
Right click on the Workspace name and select Link Structure Libraries..., navigating to the XML file defining the desired structure(s) to be throughout all the HWIs in the Workspace. Use the dialog to Add and Apply the link. Multiple libraries may be linked for use by the Workspace, HWI or Schema, OR

Right Click on a module in the single HWI file within the workspace which will use the Library and select Link Structure Libraries... Follow the same navigation and Application procedure to link the library for the node's use, OR

Right Click on a schema, which will share structure library definition use only with its subschemas, and select Link Structure Libraries... Follow the same navigation and Application procedure to link the library for the schema's use.

Now use the Structure Compose operator's Structure Name property to associate the structure previously defined in a linked xml file with the operator.

Once associated with the xml file, the Structure Compose operator provides a pin for each input to the package. The inputs may be of analog, digital or another structure type. The output is of structure type, which usually is input to a module or global scope structure variable. The schema segment below shows the variables input to a compose operator and the output structure assigned to a global structure variable, sCntrl_g.

User-Defined Properties:
Object Name. A string label that identifies the operator

Structure Name: The structure previously defined in a linked xml file with which the operator shall be associated
Display Enable Input: Adds a pin to the operator which allows for optionally accepting the input. This property determines if input pin is visible in the schema diagram. Design Pad issues a warning upon processing the schema when the pin is visible but not connected. The warning message is not issued when the pin is not visible (when this property is not checked).

Enable On: If enable is optional, specifies on what event input becomes enabled

Comments: None.

See Also: Structure Decompose, Structure Variable, Ethernet/IP Assembly