AutoCAD Electrical 2005

30 Sep, 2004 By: Bill Fane Cadalyst

Autodesk brings parametric design to the electrical engineer's desktop.

All reviews, articles, and press releases about AutoCAD Electrical seem to start in the same way, saying something like, "If you design electrical control systems, you need AutoCAD Electrical." Well, they're correct.

AutoCAD Electrical is intended for electrical control systems designers, but it does much more than just offer some 2D customizing tools. This is a fully parametric product, similar to 3D parametric design programs such as Inventor, Mechanical Desktop, SolidWorks, and the like.

 Review summary
Review summary

For example, the symbols in the library are intelligent. As you design a control circuit, you specify a relay by brand and model. AutoCAD Electrical knows how many contacts the specified relay contains and won't let you connect too many circuits to it.

In a similar fashion, you can automatically assign wire and connection numbers and component tags, and everything automatically updates when you make changes—including information within the schematic diagram and the related control panel layout drawing.

Drawings are created in the familiar 2D ladder logic format. A couple of quick examples show how AutoCAD Electrical simplifies and automates this process.

Figure 1. Ladder diagram needs a new rung.
Figure 1. Ladder diagram needs a new rung.

Figure 1 shows a portion of a ladder diagram to which we want to add a new rung.

After a simple menu or toolbar pick, AutoCAD Electrical invites us to pick a location. When we do, it adds a new rung (figure 2). Note that it took only a single location pick, as shown by the cursor in figure 2. The process didn't use object snaps, and ortho and polar mode weren't turned on. AutoCAD Electrical automatically found the two bus lines and determined the correct rung spacing.

So far, so good. Now we need to add some components to this rung. Select Components | Insert Component from the menu and proceed through a series of dialog boxes to reach a specific model number from an individual manufacturer (figure 3).

Figure 2. A single location pick adds a rung.
Figure 2. A single location pick adds a rung.

AutoCAD Electrical inserts the desired component into the selected rung of the ladder (figure 4). It cuts the rung and automatically generates and inserts all the annotation tags.

And, so it goes. We can insert pushbuttons, limit switches, pilot lights, PLCs (programmable logic controllers), and pretty much anything else from a standard catalog. Parent/child relationships are established between a relay coil and its matching contacts, and between the poles of a multipole switch. AutoCAD Electrical automatically reviews these relationships so that we can't assign too many circuits to a relay or a switch. They're taking all the fun out of engineering!

AutoCAD Electrical also automatically generates wire numbers and component tags and updates them accordingly. All tags and numbers are unique, so you never need to worry about duplicate assignments again. When placing ID tags, AutoCAD Electrical automatically searches for a clear space in the drawing.

Autocad electrical 2005
Autocad electrical 2005

Report generation is also highly automated in AutoCAD Electrical. You can create a variety of reports, including bills of materials, terminal numbers, PLC I/O addresses, and From and To listings. In fact, the Schematic Reports dialog box lists 16 different reports.

One export file format is particularly interesting—you can export an AutoCAD Electrical wire list in a format Autodesk Inventor 9 Professional can read so 3D wiring harness models can be generated from it.

AutoCAD Electrical also works the other way. You can use an Excel spreadsheet to create a PLC I/O assignment file. When you import the spreadsheet, AutoCAD Electrical generates virtually the complete 2D ladder diagram drawing in a few seconds. Figure 5 shows a portion of such a spreadsheet, and figure 6 shows the resulting AutoCAD Electrical drawing.

Figure 3. To insert a component from the catalog, choose Components | Insert Component.
Figure 3. To insert a component from the catalog, choose Components | Insert Component.

AutoCAD Electrical is helpful for creating 2D drawings for control panels. Figure 7 shows part of a control panel layout with many of the controls already placed. It also shows the dialog box used to select the next control to place. The dialog box contains a complete list of all components required in this panel, automatically derived from the ladder diagram. When you select an item, AutoCAD Electrical checks out the manufacturer and model specifications and then inserts an anatomically correct 2D picture of the component. It also generates and adds the required tags and labels.

Of course, all of this is parametric so that if you change the specification of a component in the ladder diagram, its representation changes in the panel layout drawing. The schematic and the panel always match. They're taking even more fun out of engineering!

AutoCAD Electrical also works with three-phase buses and can mix and match single-phase and three-phase within the same drawing.

Figure 4. AutoCAD Electrical inserts a relay coil into the new rung.
Figure 4. AutoCAD Electrical inserts a relay coil into the new rung.

As automatic as AutoCAD Electrical is, it still permits a great deal of versatility in defining drawing layouts. For example, you can define and create templates for drawings that specify your desired rung spacing, numbering formats, and so on.

You can create your own layers for wires, and AutoCAD Electrical recognizes objects on them as wires. You can thus have separate layers for all the different colors of wires so that the schematic colors match the real-world wire colors. Separate layers can also be defined to separate control vs. power wiring, wires by voltages, or by whatever you want.

If the supplied catalog of stock components doesn't completely meet your needs, you can easily add your own definitions on the fly.

Figure 5. Portion of a PLC I/O spreadsheet.
Figure 5. Portion of a PLC I/O spreadsheet.

All AutoCAD

AutoCAD Electrical 2005 is built on the AutoCAD platform and is a flavor of AutoCAD, just like Mechanical Desktop and Architectural Desktop.

AutoCAD Electrical maintains all of its unique information within the drawing file in the form of attributes and extended entity data. Once created, the files don't require access to any other unique support files. The files aren't damaged in any way by a roundtrip through any other flavor of AutoCAD, including standard AutoCAD, LT, and Mechanical Desktop.

New Features

For starters, the catalog is expanded—it now includes more than 43,000 stock components from many major manufacturers.

New PLC modules are released frequently. You don't need to wait for the next release of AutoCAD Electrical to access them. AutoCAD Electrical 2005 includes a new module builder that lets you add modules to the catalog as soon as they are available.

Figure 6. Portion of the drawing automatically generated from the spreadsheet in figure 5.
Figure 6. Portion of the drawing automatically generated from the spreadsheet in figure 5.

To further enhance customizability, you can merge a newer catalog database with the existing customized one on your system. All your customizations carry forward.

A new terminal strip editor makes it easy to create and manage all the terminal strips for an entire project. As usual, they're automatically generated to ensure accuracy. Everywhere I turn, they're taking more fun out of engineering!

AutoCAD Electrical offers multiple report options and now can generate multiple types of reports from within one session of the report generator.

AutoCAD Electrical now supports drawing standards as published by JIC, IEC, JIS, and GB. Inventor support now includes cables as well as individual wires. Autodesk Vault functionality makes it easier to manage and control documentation.

Figure 7. Use schematic data to generate a panel layout drawing.
Figure 7. Use schematic data to generate a panel layout drawing.

Bottom Line

The bottom line is that AutoCAD Electrical eliminates boring, repetitive, error-prone chores. It lets you concentrate on the design, not the documentation.

I can't resist—I have to close with an electrical joke. Two atoms are having a conversation.

"How did you like the party last night?"

"It was great, but I lost an electron."

"Are you sure?"

"I'm positive."

Highly Recommended.