What is a Default Symbol and How is it Used? 

An object type can be represented by various symbols.

The default symbol is the object symbol that is used when an object occurrence is created. You can assign a symbol to an object definition, which is then always used when you create an occurrence based on that object definition.

Specify default symbol

You can specify the default symbol later or when you create the object definition. If you do not specify the default symbol until after you have placed occurrences, you can pass it on to the existing occurrences. The inheritance will assign the new object symbol to all occurrences of the object definition, regardless of the models in which they occur.

If the new symbol is not permitted for an object, e.g. due to the method filter you are using, the previous symbol for the object occurrence will not be replaced.

Use default symbol

You can drag an object from the Explorer tree into a model using drag and drop. It can happen that a symbol is not allowed in the underlying model type, or is not allowed by the chosen filter. In this case, the system attempts to find an appropriate symbol for this model type. If different symbols are permitted for the object, the system will assign the first symbol it finds. If no symbol is permitted for that object in the model, no object occurrence will be created.

Use of default symbol where names are identical

If you place an object and give it the name of an object that has already been placed but which has a different default symbol, the symbol of the last object placed will be used when you reuse one of the two object definitions.

You place a function (green symbol) with the name of an object that has already been placed and which has the yellow target function symbol as its default symbol. If you select one of the object definitions with identical names for re-use, the green symbol will be used.

Use the Properties page of the object to decide whether the name of the default symbol is to be displayed.