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Resistance Module

This lesson walks through one of the simplest AP 210 examples: a single resistor. Despite its simplicity, this file demonstrates the fundamental patterns found in all AP 210 data.

The Simplest Component

A resistance module in AP 210 includes:

  • A product definition for the resistor

  • A geometric representation (the physical shape)

  • Terminal definitions (two connection points)

  • Property definitions (resistance value)

Product Definition

The product hierarchy:

#1 = PRODUCT('R1', 'Resistor 10k', 'Surface mount resistor', (#2));
#2 = PRODUCT_CATEGORY_RELATIONSHIP('cat', $, #3, #4);
#3 = PRODUCT_CATEGORY('electronic component', $);

This defines:

  • A product named "R1"

  • With description "Resistor 10k"

  • Classified as an "electronic component"

Shape Representation

The resistor’s physical shape:

#10 = SHAPE_DEFINITION_REPRESENTATION(#11, #20);
#11 = PRODUCT_DEFINITION_SHAPE('R1 shape', '', #12);
#20 = ADVANCED_BREP_SHAPE_REPRESENTATION('R1 body', (#21, #22), #30);
#21 = MANIFOLD_SOLID_BREP('R1 solid', ...);

Terminal Definitions

Each terminal is modeled as a shape_aspect:

#40 = SHAPE_ASPECT('Terminal 1', 'Pad', #11, $);
#41 = SHAPE_ASPECT('Terminal 2', 'Pad', #11, $);

Property Definition

The resistance value:

#50 = PROPERTY_DEFINITION('resistance', '', #11);
#51 = PROPERTY_DEFINITION_REPRESENTATION(#50, #52);
#52 = REPRESENTATION('resistance', (#53), #54);
#53 = MEASURE_REPRESENTATION_ITEM('resistance', #55, 10000.0);
#55 = ( MEASURE_WITH_UNIT() MEASUREMENT_UNITE() );

Key Takeaway

Even the simplest component requires a chain of entities:

  1. Product classification

  2. Product definition and formation

  3. Shape definition and representation

  4. Terminal (shape aspect) definitions

  5. Property definitions and representations

This pattern repeats for every component in an AP 210 dataset. Understanding it at this scale makes it easier to navigate larger, more complex files.