Understanding Mechanical Data Exchange Formats

The exchange of electrical and mechanical CAD data has had many import-export formats supported by Allegro/OrCAD PCB Editor (such as DXF, IDX, and IDF). Each format has maintained a set of standards accepted by the CAD industry.

DXF Bi-Directional Interface

The Drawing Interchange Format (DXF) interface lets you exchange graphical data from a layout design with that of other mechanical computer-aided design (CAD) systems. You can import the layout-editor-supported DXF entities from DXF files written according to R10 DXF to AutoCAD 2000 DXF specifications or export mechanical design data to a DXF file according to DXF Revision 12 or Revision 14 specifications.

In Allegro PCB Editor, you can export and import .dxf files to establish an interface between ECAD and MCAD. This can be done using File > Export > DXF and File > Import > DXF. When you import or export DXF data, a layer conversion file (*.cnv) is required, which maps the classes and subclasses to certain DXF layers.

Intermediate Data Format

Intermediate Data Format (IDF) is another format used to translate and exchange data between electrical and mechanical design groups. IDF represents the basic design and component geometry information as well as design constraint information such as keepin and keepout regions. The entities supported in IDF are intelligent design entities and are not simply a graphical representation of design entities.

For example, a mechanical group designs the board outline and defines critical component placement information. Using IDF, this data is passed to an electrical design group for component placement and routing and then passed back to the mechanical design group to perform more detailed 3D solid modeling and interference analysis.

Allegro PCB Editor supports IDF Versions 2.0 and 3.0.

In Allegro PCB Editor, you can perform the export and import using File > Export > IDF and File > Import > IDF.

Incremental Data eXchange (IDX) format

DXF and IDF formats are traditionally used by designers to exchange data but in these formats, in every iteration, the complete design data needs to be sent. For example, if a board outline, constraint areas, and component placement are used initially, the same data is continually exchanged bidirectionally, even if just one object is modified. This exchange format makes it difficult to manage the design impact and track changes.

The EDMD schema, a new XML-based data exchange format, has been created to aid in the exchange of ECAD-MCAD data by introducing the concept of passing incremental changes. This implies that both ECAD and MCAD tools begin at the same starting point or baseline, and any change from the baseline line is considered an incremental modification of the data. The incremental data is then passed from one CAD tool to another, not the entire CAD interface data set.

To enable tighter integration between ECAD and MCAD designers, Cadence also supports the IDX format.

IDX is an XML-based format that lets you import and export incremental data into your design. It also facilitates a codesign and collaboration-enabled environment, by providing you the ability to preview the proposed changes before accepting or rejecting them.

PCB Editor supports IDX 4.0, 3.0, and 2.0 versions to create the IDX output.

In Allegro PCB Editor, you can perform the following IDX tasks:

• Import the IDX baseline.
• Import the IDX incremental change.
• Export the IDX baseline.
• Export the IDX incremental change.
• Rebaseline the IDX import.
• Rebaseline the IDX export.

Both export and import can be done using File > Export > IDX and File > Import > IDX in PCB Editor.

The Valor ODB++ Translator

The ODB++ data format creates accurate and reliable manufacturing data for high-quality, Gerber-less manufacturing. Supplied and supported by Valor Computerized Systems© , the ODB++Inside translator lets you output the Allegro PCB Editor design into a Valor ODB++ database. It contains all CAD/EDA database, assembly, artwork, and manufacturing data.

The Allegro PCB Editor installation does not contain data for the ODB++ Inside package. ODB++ needs to be separately downloaded from the Valor website before you can export the Allegro PCB Editor design data using  File > Export > OBD++ Inside (odb_out command).

You can read in detail about these formats from the following link:

Converting Third-Party Designs and Mechanical Data

Feel free to comment below if you want to know in detail about any of the Mechanical Data Exchange formats.

This is in continuation to our last poll about the CAD Translators, in case you have missed it, you can have a look from below link:

Allegro CAD translators: What can be imported into PCB Editor?