188.8.131.52. Information requirements and data functionality. Currently, engineering drawings form the mainstay of product definition and form the accepted medium for viewing computer generated data. Geometry and text annotation form the majority of data items. Extensive use is made of dimensions, sectioned areas, text notes, and feature control symbols. Non-geometric information in the form of color, line weight, line font, and level is needed as well. Finally, relationships among the data help to structure the large quantities of data. Information requirements for this application subset include (but are not limited to):
184.108.40.206. ASME Y14.26M entity subset specification. Table II lists the entities of this subset. Only ASME Y14.26M entities which are enumerated in this table shall be used for representing engineering drawing product definition data. Other valid ASME Y14.26M entity types may be present in the file as described by 3.1.1. Additional requirements are placed on the global section of a file, and certain field value restrictions are placed on the range of parameter values in both the directory entry(DE) and the parameter data(PD) sections of a valid ASME Y14.26M file.
When the form column in Table II is blank for an entity which has multiple form numbers, all forms of that entity are included in the subset.
|104||1||Conic arc - ellipse||F104X|
|104||2||Conic arc - hyperbola|
|104||3||Conic arc - parabola|
|106||1||Copious data - coordinate pairs|
|106||2||Copious data - coordinate triples|
|106||11||Copious data - Piecewise planar, linear string (2D linear path)|
|106||12||Copious data - Piecewise linear string (3D linear path)|
|106||21||Centerline through circle centers|
|106||31||Section lines - General use, iron, brick, stone masonry|
|106||32||Section lines - Steel|
|106||33||Section lines - Bronze, brass, copper|
|106||34||Section lines - Plastic, rubber|
|106||35||Section lines - fire brick, refractory material|
|106||36||Section lines - Marble, slate, glass|
|106||37||Section lines - Lead, zinc, magnesium, insulation|
|106||38||Section lines - Aluminum|
|106||63||Simple closed planar curve|
|112||0||Parametric spline curve||F112X|
|114||0||Parametric spline surface|
|118||0||Ruled surface (Equal relative arc length)|
|118||1||Ruled surface (Equal relative parametric values)|
|120||0||Surface of Revolution|
|126||0||Rational B-spline curve||F126X|
|126||1||Rational B-spline curve - Line|
|126||2||Rational B-spline curve - Circular arc|
|126||3||Rational B-spline curve - Elliptical arc|
|126||4||Rational B-spline curve - Parabolic arc|
|126||5||Rational B-spline curve - Hyperbolic arc|
|128||0||Rational B-spline surface|
|128||1||Rational B-spline surface - Plane|
|128||2||Rational B-spline surface - Right circular cylinder|
|128||3||Rational B-spline surface - Cone|
|128||4||Rational B-spline surface - Sphere|
|128||5||Rational B-spline surface - Torus|
|128||6||Rational B-spline surface - Surface of Revolution|
|128||7||Rational B-spline surface - Tabulated cylinder|
|128||8||Rational B-spline surface - Ruled surface|
|128||9||Rational B-spline surface - General quadric surface|
|142||0||Curve on a parametric surface|
|212||1||General note - dual-stack dimension|
|212||2||General note - imbedded font change dimension|
|212||3||General note - superscripted dimension|
|212||4||General note - subscripted dimension|
|212||5||General note - superscripted/subscripted dimension|
|212||6||General note - multiple stack - left justified|
|212||7||General note - multiple stack - center justified|
|212||8||General note - multiple stack - right justified|
|212||100||General note - simple fractional dimension|
|212||101||General note - dual stack fractional dimension|
|212||102||General note - imbedded font change/double fractional dimension|
|212||105||General note - super-/sub-scripted fractional dimension|
|214||1||Leader arrow - Wedge||F214X|
|214||2||Leader arrow - Triangle|
|214||3||Leader arrow - Filled triangle|
|214||4||Leader arrow - No arrowhead|
|214||5||Leader arrow - Circle|
|214||6||Leader arrow - Filled circle|
|214||7||Leader arrow - Rectangle|
|214||8||Leader arrow - Filled rectangle|
|214||9||Leader arrow - Slash|
|214||10||Leader arrow - Integral sign|
|214||11||Leader arrow - Open triangle|
|214||12||Leader arrow - Dimension origin|
|216||1||Linear dimension (Diameter)||F216X01|
|216||2||Linear dimension (Radius)||F216X01|
|218||1||Ordinate dimension with datum||F218X01|
|222||1||Radius dimension/multiple leader||F22201X|
|228||1||Datum feature symbol|
|228||2||Datum target symbol|
|228||3||Feature control frame|
|230||0||Sectioned area (Standard Crosshatching)||F230X|
|230||1||Sectioned area (Inverted Crosshatching)||F23001AX|
|304||1||Line font definition - subfigure|
|304||2||Line font definition - repeating pattern||F30402X|
|402||3||Views visible instance|
|402||4||Views visible, Color, Line weight instance|
|402||7||Unordered group without back-pointers instance|
|406||1||Property - Definition levels|
|406||3||Property - Level function|
|406||15||Property - Name|
|406||16||Property - Drawing size|
|406||17||Property - Drawing units|
|406||18||Property - Intercharacter spacing||F40618X|
|408||0||Single Subfigure Instance||F408X|
|410||0||View - Orthographic parallel|
|410||1||View - Perspective|
|412||0||Rectangular Array Subfigure Instance|
|414||0||Circular Array Subfigure Instance|
102 Composite Curve. Composite curves are intended for showing connectivity and continuity. They shall contain a minimum of two entities one of which shall be a curve the line entity included.
124 Transformation Matrix. Defining matrices are used to position an entity into model space from its definition space. When entities share the same plane of definition, they shall use the same transformation matrix to avoid multiple identical matrices being included in the file. If an entity contains translation information in its PD section, a transformation matrix shall not be used to translate the entity.
202 Angular Dimension. This entity shall have two leaders, and a vertex point. The Z displacement of the vertex point can be attained from any of the subordinates.
206 Diameter Dimension. This entity shall specify its arc center (may not be defaulted). The Z displacement of the arc center can be obtained from the subordinates. The arc center shall be valid. If multiple leaders occur, the first segment of each leader shall be collinear and opposite in direction.
212 General Note. General notes shall use a font code to minimize the number of text strings in the note. At least one string is required, but the number of different strings shall be minimized. Form numbers plus position information on each string shall be used. The Rotation Angle field shall contain the string angle. Transformation matrices shall not be used for string angles. Null strings are allowed and may be used to pattern a note into one of the standard forms.
216 Linear Dimension. When there are two witness lines, they shall be parallel to each other.
218 Ordinate Dimension. This entity shall not be used in place of the general label. The leader shall contain only one segment.
222 Radius Dimension. This entity shall specify its arc center (may not be defaulted). Z displacement of the arc center can be attained from any of its subordinates. Arc center shall be valid. If multiple leaders occur, the first segment of each shall be collinear. If two leaders are used, one and only one shall be of Form 4.
228 General Symbol. This entity shall be used for annotation. Flags in the subordinate entities (even geometry) shall be set to annotation. This entity shall not be used in place of a subfigure or group. All subordinate entities to the general symbol entity shall be coplanar.
230 Sectioned Area. This entity is used to provide for area fills. The normal distance between lines is constant and shall not be zero. Wider spaces between lines are to be considered blank lines with regard to normal distances. Boundary curve and islands are closed and not self- intersecting. Island interiors are mutually disjoint. Islands lie in the interior of the boundary curve. Boundary curve and islands can be logically dependent and do not need to be marked as annotation if they are not annotation.
404 Drawing. The drawing entity defines the basic engineering drawing format for each sheet. One drawing entity shall exist in the file for each sheet, or collection of sheets, of an engineering drawing. An example of a collection of sheets would be several B size sheets placed in an H size engineering drawing. All entities pointed to by the drawing entity shall be physically dependent and shall be flagged as annotation.
406 Form 5 Line Widening. The only allowed use of the line widening property is the case when physical model space width is important. It shall not be used to indicate plotter width or line weight.
406 Form 15 Name. This entity is used to convey the drawing name. A Drawing Name using Entity 406, Form 15 is required. If there is no name available in the architecture of the system, the preprocessor shall insert one, a reasonable default being global parameter 3.
406 Form 16 Drawing Size. A drawing size property shall be included for each drawing entity in the file. If drawing size is not in the architecture of the system, the preprocessor shall insert one and the drawing size for each sheet shall match the drawing size letter defined in the start section (see 220.127.116.11.1).
406 Form 17 Drawing Units. A drawing units property shall be included for each drawing entity in the file. If drawing units is not in the architecture of the system, the preprocessor shall use the defaults given in global parameters 14 and 15.
The simplest entity type shall be used to represent each piece of geometry, and zero size entities shall not be used. For instance, a B-Spline curve shall not be used to represent a circular arc. A zero length line entity or a zero diameter circle shall not occur in the file.
All 200 series entities shall be flagged as annotation and shall be parallel to the viewing plane, except for crosshatching. All dependent entities with parent 200 entities shall be flagged as annotation and shall be coplanar with their parent. The only exception is for geometry entities associated with the Sectioned Area (230 and 106 Forms 31-38). Any annotation entity which points to multiple leaders and multiple witness lines shall order those leaders and witness lines so that leader-1 corresponds logically to witness-1 and leader-2 to witness-2.