Model Reference Manual
Structural Design Using Catalogue Components : MODEL, Owning and Attached Parameters : Setting Unit Qualified Parameters
Setting Unit Qualified Parameters
DESP may be entered as pure numeric values or as unit qualified quantities. If it is entered as a physical quantity the dimension of the quantity will be persisted and used whenever the parameter is queried and used.
If the design parameter is purely numeric it is stored as that number and this will be consistently retrieved when the parameter is used. If it is used in an expression its physical quantity will be NONE so that if it is subsequently combined with other physical quantities it will follow the normal rules of combination described in the Database Management Reference Manual, Numeric (Real) Expressions.
For example in the case of a parameter of value 254
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If it is added to a distance it will be assumed to be a distance in the current working units (in PML or command line expressions) or in database units (mm) in catalogue and property expressions. For example adding to 100cm with current distance cm will produce 354cm (current units cm) and 1254mm (current units mm) and 257.8in (current units inch).
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If it is added to a number it will return a number, (e.g adding to 100 will produce 354 always).
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If it is multiplies with a distance it will simply scale the distance by its value. Multiplying with 100cm will produce 25400cm.
If the parameter is unit qualified it will be stored in the database units of the relevant physical quantity (e.g. 10inch will be stored as 254 (i.e. in mm)). In addition the system will record that that parameter is a distance and will always report the value of the parameter unit qualified by the (then) current working units of distance (e.g. it will be 25.4cm when current units are cm). In expressions:
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When such a distance parameter is added to another distance the result will also be a distance and it will be the same distance regardless of the then current working distance units. (e.g. adding to 100cm will always produce the equivalent of 125.4cm)
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If it is added to a number it will produce a distance whose value depends on current working units applied to the other number. (e.g. adding to 100 produce 125.4cm (current units cm) and 110inch (current units inch).
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If it is multiplied with another distance it will produce an area of the same value whatever the current working units of distance or area are.
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Adding the parameter to a mismatched physical quantity (e.g. 90degrees) will generate a warning/error.
Note:
The same behaviour occurs when using unit qualified catalogue parameters
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