General about Functional Descriptions

Functional descriptions are strings (up to 75 character long). They may be fixed strings but can also contain predefined parameters that may be replaced by actual values fetched from the part that the tag is fixed to. FD:s can be assigned to panels and to physical parts in panels, that means, to plates, stiffeners, welded flanges, pillars, brackets and clips.

Each single FD consists of two parts: The FD string and an index associated with that string. The index is an integer (in the range 0 -32767) that must be unique for a certain FD, that means, there is a one-to-one relation between the string and the index. FD:s are stored in model objects via the index which thus is the "handle" by which the FD string is accessed.

An FD with index 0 is the default FD. This default FD is applied for all parts which have not got any explicitly defined FD. An undefined FD (that means, an index without any corresponding string) may be assigned to a model part. Such an FD may be defined afterwards but if it is asked for before being defined an error message may be issued (depending on the function where it is asked for).