Integrate database and CAD: an easier way to deal with wiring diagrams

Communications News, March, 1990 by Tim Frye

INTEGRATE DATABASE AND CAD

For thos of us fortunate enough to be using computer-aided design or database programs at our facility, the advantages of computerized documentation are apparent.

Unfortunately, wiring documentation is one area that has always been difficult to accomplish with a computerized system.

The problem is that the information on those pretty CAD drawings cannot be directly transferred to an external database program.

After we generate a databaseor wiring diagram, we have to rekey all information into the other program.

With this system, even small modifications become nightmares.

An integrated software package would be nice, but none exist.

But I've found a nice solution.

If you are using the ORCAD Schematic Capture program for your wiring diagrams, you can create coded wiring drawings with the cable codes accessible by an external database program through the use of several OrCAD utility programs.

At Ohio University-zanesville, we use a color coding scheme for cables, but any alphanumerical system will work just as well.

The first step involves creating a custom library part for OrCAD to use in your drawings.

This is an easy process.

First, using DOS, make a library sub-directory.

For example:

MD/ORCAD/

LIBRARY/

CUSTOM.LIB

.

The next step is to create your custome part.

I called mine "code," but you can name it anything you like.

Using DOS EDLIN, or any text editor, create the file CUSTOM.SRC as shown in Figure 1.

Save the file on the OrCAD directory at this point.

At the DOS prompt, type:

COMPOSER

CUSTOM.SRC\

ORCAD\

LIBRARY\

CUSTOM.LIB

.

You have just created your custom part.

By the way, be sure to configure OrCAD to load your new CUSTOM.LIB.

This procedure, as well as how to use the utility programs, is well documented in the OrCAD user manual.

It is now possible to call up the part for your wiring diagrams simply by typing "CODE" at the GET? prompt.

Once you place the part on your drawing, simply edit the part name and reference to input your cable identifier and pair color.

For example, "CODE" and "?" might become "10G456" and "R-B."

Now you have to transfer the cable-identification data to a database.

After completing your cabling drawing, use the OrCAD PARTLIST utility to create an ASCII text file. Type

PARTLIST (YOUR

DRAWING) (YOUR

TEXTFILE)/S

to create a list of cables and pairs.

It you inadvertently forget to edit cables or have duplicate identifiers, PARTLIST will produce a warning message and identify the problem.

See Figure 2.

You can now import the information into any database program that will read a standard text file.

The only real trick here is to format the first four fields of your database to capture the information correctly.

Once the info is in your documentation database, it can be added to or sorted.

This is what makes databases or great to use in the first place.

See Figure 3.

Updating the database from this point becomes a matter of simply adding or changing cable on the drawing, generating a new partlist file, and reading it into the database using the cable code as an exclusive sort.

While the intial work to create the custom part may not seem to be worth the effort, just think how many cables you have in your plant and how much trouble it is to redraw your prints every time you add just one. This alternative can simultaneously generate a drawing and provide all the pertinent info at the touch of a button.