The SEDRIS Data Representation Model
APPENDIX A - Classes
Translation Control Link

Class Name: Translation Control Link

Superclass - <Control Link>

Subclasses

This DRM class is concrete and has no subclasses.

Definition

An instance of this DRM class is a specialized <Control Link> instance used to provide the connection between an ordered aggregation of <Expression> instances and the target fields of a <Translation> instance.

Primary Page in DRM Diagram:

Secondary Pages in DRM Diagram:

Example

  1. Consider a <Geometry Model> instance representing a building, containing a <Geometry Model Instance> instance representing a lift cage (elevator car), where both <Model> instances are specified in a 3D LSR SRF, and the lift cage is intended to be a moving part of the building model. The <LSR Transformation> instance used to instance the lift cage into the building specifies a <Translation> component with a <Translation Control Link> instance as depicted in Figure 6.73:

    Translation_Control_Link, Example 1

    Figure 73 — <DRM Translation Control Link> example

    This <Translation Control Link> instance specifies:

    1. A <Literal> component, defining the lower limit (the bottom of the lift shaft) of the translation, in this case, 0.0 metres.

    2. A <Literal> component, defining the upper limit (the top of the lift shaft) of the translation, in this case, 500.0 metres.

    3. A <Variable> component, the actual translation of the lift cage along the W axis of the lift shaft at any given moment.

      The <Variable> instance's meaning = {SE_ELEMTYPCOD_VARIABLE, {SE_VARCOD_TRANSLATION_AMOUNT}}

      The <Variable> instance's value_unit = EUC_METRE and its value_scale = ESC_UNI, because <Translation> instances define their fields in metres.

FAQs

No FAQs supplied.

Constraints

Composed of (two-way) (inherited)

Component of (two-way)

Inherited Field Elements

SE_String description; 1

Field Elements

SE_Integer_Positive expression_index; 2
SE_Integer_Unsigned lower_expression_index; 3
SE_Integer_Unsigned upper_expression_index; 4

Notes

Fields Notes

description

The description field specifies a text description of the purpose of the <Control Link> instance.

expression_index

For a given <Translation Control Link> instance C, expression_index serves as a one-based index into the ordered <Expression> components of C such that the specific <Expression> instance selected specifies the value of the translation_amount field of each <Translation> instance controlled by C.

lower_expression_index

For a given <Translation Control Link> instance C , if lower_expression_index > 0, it serves as a one-based index into the ordered <Expression> components of C such that the specific <Expression> instance selected specifies the lower limit for the translation_amount of each <Translation> instance controlled by C. If lower_expression_index = 0, it indicates that no such lower limit is being specified.

upper_expression_index

For a given <Translation Control Link> instance C, if upper_expression_index > 0, it serves as a one-based index into the ordered <Expression> components of C such that the specific <Expression> instance selected specifies the upper limit for the translation_amount of each <Translation> instance controlled by C. If upper_expression_index = 0, it indicates that no such upper limit is being specified.


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Last updated: July 26, 2006 Copyright © 2006 SEDRIS