Model Reference Manual
General Commands
: Setting Working Units and Tolerances
Setting Working Units and Tolerances
These functions allow the user to set the dimensioning units and precision for design placement and element searching operations. The designer can choose at any time to work with metric or imperial units and can differentiate between the units used for nominal pipe bores and for general linear dimensions. Tolerance settings are available for general 3D positioning, plus special tolerance controls for pipe and structural steelwork layouts. A search radius (the ‘hit radius’) can be specified for cursor picking operations.
Current Working Units Initialisation
Current units are set on session start. Their configuration is dependent on the setting of the BUNIT and DUNIT attributes in the first UNIT element found in a catalogue database in the MDB.
The value of the BUNI and DUNI are used for setting BORE and DISTANCE current working units. The BUNI value is applied to current BORE units (one of MM, INCH or FINCH) and the DUNI value is the current DISTANCE unit (any distance standard unit including MM, INCH or FINCH).
The setting of DUNI also determines which of imperial or metric units are to be generally used.
Some physical quantities will be initialised to use their database unit regardless of imperial or metric DUNI settings (e.g. angles, voltages, and current, time, power).
The current working units of most other quantities are directly dependent on (i.e. DERIVED from) the setting of the current distance unit (and sometimes current units of other quantities. For example, Area, Volume, Surface and Linear Density, Content, Temperature gradient.
Some quantities have special initial imperial or metric settings applied which are dependent on whether the distance unit is imperial or metric
•
Mass will be kg or lb
•
Temperature will be degC or degF
•
Pressure will be pascal or PSI
•
Force will be newton or lbf
•
Density will be kg/m3 or lb/ft3
•
Unit mass will be kg/distance or lb/distance
1974 to current year.
AVEVA Solutions Limited and its subsidiaries. All rights reserved.
