AP203 (Configuration Controlled 3D Design)
AP203 was the first major Application Protocol of the STEP standard. It focused on the exchange of 3D design data with configuration management information.
1. Purpose of this AP
- Exchange of 3D mechanical design data.
- Manage design-control information (versions, approvals, person/organization).
- Provide a baseline for 3D B-rep geometry exchange.
2. Editions and Capabilities
The capabilities of AP203 changed significantly between its two major editions.
Edition 1 (Legacy)
- Geometry: 3D B-rep (Advanced B-rep, Faceted B-rep, etc.) and Wireframe.
- Styling: ❌ No support for colors, layers, or transparency.
- Metadata: Basic product identification and version control.
Edition 2 (Modern)
Published in 2011 to align with AP214, Edition 2 added significant features:
- Styling: ✅ Support for Colors and Layers.
- PMI: Basic support for Geometric Dimensioning and Tolerancing (GD&T).
- Assembly: Improved support for assembly structures.
- Compatibility: Highly compatible with AP214.
3. Limitations
- AP203 Edition 1: Any color information in the CAD system will be lost when exporting to this format.
- Interoperability: Many older systems only support Edition 1. If colors are missing in a transfer, check if the exporter was set to "AP203" (defaults to Ed1 in some tools).
4. Recommended Use Cases
- Legacy data exchange where only geometry is required.
- Very old CAD systems that do not support AP214 or AP242.
- When explicitly requested by a supplier using older workflows.
5. Key Entities
- PRODUCT: The root part or assembly.
- MANIFOLD_SOLID_BREP: The standard entity for 3D solid geometry.
- APPLICATION_PROTOCOL_DEFINITION: Identifies the AP version in the header (e.g.,
'config_control_design'for Ed1).