Symbols have a graphic, connection points, and placeholders (with formatting and position) for device tags, connection point designations, connection point descriptions, cross-references, and other properties. The logic for the symbol is stored in the function definition which the symbol refers to.
The following symbol properties are used in order to identify the symbol:
- Symbol number: The symbol number defines the position of the symbol in the symbol library. This number is only used internally for report-related purposes and is unique to each symbol library. The symbol is internally referenced by the symbol number.
- Symbol name: The symbol name, which should begin with the device identifiers, allows easy identification of the symbol and can also be used as search criteria when selecting symbols.
- Connection point designation: The connection point designation is the consecutive connection point number on the symbol. This allows every connection point to be uniquely identified. The logical data for the connection points lies in the function definition. If, for example, a change-over contact is created, then the three connection points have the numbers "1", "2," and "3". In the function definition assignment table, the appropriate logical data for the function and the connection points is stored under "change-over contact". The standard symbol is used to define which connection point the "root" of the change-over contact is.
- Connection point description: The connection point description is not suited to identification of the symbol because it only contains an additional description. It is therefore not unique and may appear several times.
See also