Standard for the Exchange of Product Data (STEP) is a ISO standard industrial automation systems product data representation and exchange format.
The file structure for a STEP file has a modular structure which makes it easier for developers to adapt the format to their own needs. The modules are called “classes” and are classified using numbers as follows:
Part 11: The EXPRESS language reference manual.
Part 12: The EXPRESS-I language reference manual
The EXPRESS language is a data definition language that is used to represent the structure of data and any constraints that may apply to it. The information models contained in STEP Integrated Resources and Application Protocols are defined using EXPRESS.
21 to 26: Implementation methods: describe the correspondences between STEP and other formal languages. (text encoding, C++ binding, ...)Each AP has its own subset of entities specific for the industry branch the AP was developed for Alias (supports the AP203 and the AP214.)
Application protocol support for STEP formats
The geometric descriptions contained within ISO10303-203 and ISO10303-214 are identical and comprises the core of the implementation of the translator. The following table shows the mappings made by Alias.
STEP Entity | Alias Entity |
---|---|
Cartesian Point | Point |
Line | B-spline Curve |
Circle | B-spline Curve |
Ellipse | B-spline Curve |
Parabola | B-spline Curve |
Hyperbola | B-spline Curve |
PolyLine | B-spline Curve |
Composite Curve | B-spline Curve (Grouped) |
Trimmed Curve | B-spline Curve |
B-spline Curve | B-spline Curve |
Plane | B-spline Surface |
Cylindrical Surface | B-spline Surface |
Conical Surface | B-spline Surface |
Spherical Surface | B-spline Surface |
Toroidal Surface | B-spline Surface |
Surface of Linear Extrusion | B-spline Surface |
Surface of Revolution | B-spline Surface |
B-spline Surface | B-spline Surface |
Rectangular Trimmed Surface | Trimmed Surface |
Curve Bounded Surface | Trimmed Surface |
Offset Surface | B-spline Surface |
Manifold Solid Brep | Shell (Closed) |
Shell Based Surface Model | Shell (Open/Closed) |
Pro/ENGINEER options for export and import
To make the import and export of IGES and STEP files easier for Alias to read.
IGES_OUT_ALL_SRFS_AS 128 IGES_OUT_SPL_CRVS_AS_126 YES IGES_OUT_SPL_SRFS_AS_128 YES IGES_OUT_MIL_D_28000 NO IGES_OUT_TRM_SRFS_AS_143 NO IGES_OUT_TRIM_CURVE_DEVIATION DEFAULT INTF_OUT_BLANKED_ENTITIES NO INTF3D_OUT_EXTEND_SURFACE YES INTF3D_OUT_FORCE_SURF_NORMALS YES IGES_IN_106_F2_AS_SPLINE NO IGES_IN_DWG_LINE_FONT YES IGES_IN_DWG_PNT_ENT YES IGES_IN_DWG_COLOR YES FIX_BOUNDARIES_ON_IMPORT YES