CAD Support

Data formats used in test development include circuit board data transfer formats, drawing formats, Gerber formats, a variety of tabulated data formats for objects like probes, and a variety of Bill of Materials (BOM) formats.

Circuit board data transfer formats imported by TestSight products include:

  • ACCEL ASCII
  • GenCAM 2511A (gcm)
  • GenCAD (cad)
  • GenRad 228X
  • ODB++ (tgz, zip, tar, folder)
  • Mentor Graphics Integra (txf)
  • Mentor Graphics Neutral (neu)
  • Cadence Allegro®, Single File “Extract” (fab)
  • Cadence Allegro®, Multiple File “Extract” (b,s,p,r)
  • PADS Perform
  • PADS PowerPCB (asc)
  • IPC 356A (.ipc)
  • IPC 2581 (.cvg)
  • Unidat (uni)
  • Gerber
  • Pick and Place (using wizard)
  • Keysight 3070 Board, Board_XY and Fixture files

More are being added all the time — contact us for further information.

For tabulated data formats, a variety of Wizard import tools are available, including BOM Wizard, Probe Wizard and others.

TestSight technology supports HPGL and Autodesk DXF graphics formats.

GenCAM

TestSight has built-in import of the industry standard GenCAM format directly into the TestSight object model.

GenCAM is a format for electronic data interchange. The primary focus of the GenCAM standard is Printed Circuit Board (PCB) fabrication and testing.

The GenCAM file includes all information about a PCB, including route (trace) information, part information, net information, etc. As the GenCAM file is loaded, TestSight builds system objects.

When TestSight loads GenCAM components or routes (Parts and Nets), the parts and nets are sorted alpha-numerically. This is useful when iterating through a parts or nets collection to build a listing, such as a tree view.

GenCAM supports some higher level object definitions, such as fixture design. When these higher level objects are incorporated in the GenCAM file, TestSight automatically builds structures to support the GenCAM objects. For example, a fixture is essentially a product, containing one or more circuit boards. When TestSight encounters a fixture object in GenCAM, it builds a TestSight Product object.

TestSight does not currently write the GenCAM standard. Future releases will have full read and write capability.

GenCAD

TestSight has built-in import of the GenCAD Version 1.4 format directly into the TestSight object model.

GenCAD is a format for electronic data interchange. The primary focus of the GenCAD standard is Printed Circuit Board (PCB) fabrication and testing.

The GenCAD file includes all information about a PCB, including route (trace) information, part information, net information, etc. As the GenCAD file is loaded, TestSight builds system objects.

When TestSight loads GenCAD components or routes (Parts and Nets), the parts and nets are sorted alpha-numerically. This is useful when iterating through a parts or nets collection to build a listing, such as a tree view.

GenCAD supports some higher level object definitions, such as fixture design. When these higher level objects are incorporated in the GenCAD file, TestSight automatically builds structures to

support the GenCAD objects.

ODB++

ODB++ is a printed circuit board manufacturing database containing all the elements necessary to build and describe a PCB. ODB++ is a format based on a hierarchical folder structure. Typically the folders are compressed into a .tgz file. However ODB++ can also come uncompressed, zipped, or as a .tar.

ODB++ is supported by most of the major CAD design/layout packages (Zuken – CAD STAR, Board Designer, Visula – Altium – Protel and PCAD – Cadence – Allegro, OrCAD – Mentor Graphics – Board Station, Expedition Enterprise, Pads) and is a standard input for both electronic manufacturing and CAD design.

Cadence Allegro

Cadence Allegro stores its CAD data in a binary board file (.brd) that cannot be read by third party software. To allow other users access to the CAD data in the .brd file, Allegro provides an extraction utility, ‘extracta.exe’, which is usually located in the following folder: %INSTALL_DIR%\tools\pcb\bin.

Allegro Extracta.exe accepts the .brd file and a script language command file to determine which information to extract and copy to a more readable ASCII-formatted file. After the CAD data are extracted from the .brd file, four files are generated. These four files are loaded by TestSight to generate an Allegro import.

The Allegro Extract files include all information about a circuit board, including route (trace) information, part information, net information, etc. As the Allegro Extract files are loaded, TestSight builds system objects.

When TestSight loads the Allegro Extract components or routes (parts and nets), the parts and nets are sorted alpha-numerically. This is useful when iterating through a parts or nets collection to build a listing, such as a tree view.

Running Allegro Extract

1. Obtain a copy of the Allegro Extract script language command file ‘valext.txt’ or ‘TestSightAllegroExtract.txt’. These command files are similar except that ‘TestSightAllegroExtract.txt’ has additional fields extracted to permit accurate loading of bead probe mask objects.

2. Run the Allegro Extract utility by executing the application from a Unix shell window or Windows command prompt. From the Unix shell or Windows command prompt type: ‘extract’ (without the single quotes).

Note: For Allegro users running under Windows NT, when executing Allegro Extract you may inadvertently call the Microsoft EXTRACT utility for extracting compressed files from .CAB files. This executable is commonly located in the WINDIR directory (i.e., ‘C:\WINNT\extract.exe’). If this is the case, the Microsoft EXTRACT file can be temporarily renamed so that it will not present a conflict, or the full path and name of the Allegro Extract utility you do wish to use can be specified.

3. When running Allegro Extract, respond to the prompts as follows:

Layout name (*.brd): path/boardname return
Extract command file (*.txt): path/valext Extract output filename (*.txt): path/brd
Additional output filename (return if none) (*.txt): path/pad return
Additional output filename (return if none) (*.txt): path/sym return
Additional output filename (return if none) (*.txt): path/rte return
Additional output filename (return if none) (*.txt): return

Note: The Allegro Extract utility will produce 4 files: brd.txt, pad.txt, sym.txt and rte.txt, at the specified path.

If Allegro Extract Fails

Allegro Extract may fail to complete processing if the .brd file is missing user-defined attributes that the script language command file (‘valext.txt’ or ‘TestSightAllegroExtract.txt’) is looking for. If this happens, the extract.log file will identify the missing attributes. Missing attributes are identified in the extract.log file as follows:

#User Attributes are added here:

BARCODE
Field ‘BARCODE’ is unknown

The above example indicates that the attribute ‘BARCODE’, defined for extraction in the script language command file, was NOT found in the .brd file. In order to process the .brd file, you will have to comment-out the attribute ‘BARCODE’ in the script language command file. To do this, open the ‘valext.txt file and place a ‘#’ (without the single quotes) in front of the keyword ‘BARCODE’.

Gerber

In some cases, it may be necessary to import lower level data because the CAD data may no longer exist or is not available. In this case, you may need to import data from your Gerber and associated files. Since most circuit boards are fabricated using a Gerber file, these files are nearly always available.

The Gerber format is a standard for printed circuit board (PCB) fabrication, and is usually one of the last steps in the fabrication process. For this reason, it is sometimes necessary or desirable to import the circuit board information directly from a Gerber file (RS-274D & RS274X) rather than a higher level CAD file such as GenCAM, GenCAD, Cadence Allegro, or Mentor Neutral. This may be because it is impossible to obtain the CAD data.

In creating a TestSight project from Gerber data, the Gerber files are used to create the graphics display, while other files are merged to the Gerber to provide the netlist and parts list information.

Using Gerber is inherently complex because of the very wide variety of data used in the manufacturing process. DeMille Research provides a translation service to create TestSight project files from virtually any data.  Contact Us for more information about our TestSight Gerber translation service and to quote your next job.