Defining communication objects involves three layers of elements:
·The ComObject element specifies the object number and default values for the properties of the ComObjectRefs.
·For each ComObject there may be zero or more ComObjectRef elements. These are the elements which correspond to the individual user-visible objects.
oFor ETS3: the fact that there may be at most one ComObjectRefRef per ComObjectRef.
oFor ETS4/ETS5: multiple ComObjectRefs are only required if the values shall be stored separately (e.g. if different default flags apply for a communication object on operation mode).
·For each ComObjectRef element, there is one (or in case of ETS4/ETS5 any number of) ComObjectRefRef elements in the Dynamic part.
To create a communication object:
·Select the application program, the Static or the ComObjects node
·Execute the Add New ComObject command
·Normally, a ComObjectRef will be created immediately, but this can be switched off
·If necessary create additional ComObjectRef elements by the Add new ComObjectRef command or by copying an existing ComObjectRef element
The creation of the ComObjectRefRef elements is described in Design Dynamic Structure.