Parameter connection guidelines

Use the
parameterConnection
keyword to announce a connection.
A parameter connection is a relationship between two parameters. Changing a tag’s connection does not modify the file the tag resides in.
Connections to parameter bit, array, and structure members are allowed.
InOut parameters allow only a single connection to the whole tag. Connections to InOut members are not allowed. You can connect the InOut to a member of an Input parameter or controller tag. InOut parameters that are arrays cannot connect to members of an Input or controller tag. InOut parameters can only connect to the whole tag.
InOut connection validation
Unconnected InOut parameters in a Smart Object base instance cause a validation error, and unconnected InOut parameters in a Smart Object definition do not cause a verification error. Optionally, you can choose to connect the InOut parameter in the Smart Object definition and it will be inherited in all instances.
A Smart Object instance that contains an unconnected InOut parameter causes a validation error in both the Library view and the System View. However, any Smart Objects that inherit from that Smart Object will not show a validation error for the unconnected InOut parameter, because there is already a validation error in the base instance.
Keep these guidelines in mind concerning InOut connection validation:
Unconnected InOut parameters in a Smart Object definition do not cause a validation error because each related Smart Object instance might require its own unique connections.
Unconnected InOut parameters in the first (base) instance of a Smart Object cause a validation error. This can be a stand-alone instance or an inherited instance. However, any Smart Object Instances that inherit from this base instance do not cause a validation error because the error already exists and must be fixed in the base instance.
When there is an unconnected InOut parameter in a Smart Object instance in the Library view (nested below a Smart Object definition), the view indicates the unconnected InOut parameter for this Smart Object instance (if it is a base instance or not inherited). When the user creates an instance of that Smart Object in the System view, a validation error does not appear for the inherited instance in the area model because an error already appears for the base instance in the Library view, and that is where the user needs to fix it: in the base instance.
TIP: When you click on a Smart Object, the Properties panel shows if it is a definition or an instance above the Smart Object name.
Overlapping connections to an Input parameter or parameter members are not allowed.
You can connect Input parameters to a whole tag, or to individual members of that tag, but not both. Also, member connections are not allowed to overlap. For example, you cannot create connections to both MyInputTimer.PRE and MyInputTimer.PRE.0.
Parameter connections to controller and device tags are created in the .logix controller file.
Connected parameters must either be contained in the same Smart Object definition or must be assigned to the same controller. Connections to devices must have the device and parameter assigned to the same controller.
Connections must be connected from inputs to outputs, but the order of the connections does not matter. You can connect inputs to outputs, or outputs to inputs.
You can use the parameterConnection keyword to declare connections inline within Smart Objects and controller applications.
The controller application is the better place to create the connection because Smart Objects are self-contained elements and cannot reference a device directly. The parameterConnection keyword within a Smart Object does not support device tags and can only connect the program parameters within the Smart Object.
This example shows a parameter connection in a controller application that references a device tag. This connection would not work within a Smart Object.

    parameterConnection myAO.program.input myDevice.tag