Creating AutoCAD Electrical Blocks (Avatech Tricks Tutorial)

31 Dec, 2006 By: Greg Shaffer

Use Symbol Builder to convert standard blocks.

In AutoCAD Electrical, the symbols that you place into your schematics are basically AutoCAD blocks that have been made "intelligent" with added attributes. There are hundreds of these smart blocks, or symbols, included with AutoCAD Electrical. But what about components that aren't part of the extensive library? You could insert plain AutoCAD blocks into your drawings, but then you would lose AutoCAD Electrical's parametric abilities -- the ability to tie components together and to automatically generate reports based on information stored in the application's intelligent blocks. This is where the Symbol Builder, formerly called the Black Box Builder, comes in. AutoCAD Electrical's Symbol Builder includes tools to help you turn ordinary AutoCAD blocks into intelligent electrical blocks. Although you could use standard AutoCAD tools to add the attributes needed, the tools in the Symbol Builder make the task much easier -- and faster.

Let's say you need a switch symbol that isn't included in the AutoCAD Electrical Library. There are a couple of ways that you can create a reusable intelligent symbol. If you have to, you can sketch the symbol from scratch in AutoCAD Electrical, or AutoCAD. If you can get an AutoCAD drawing of the symbol from the manufacturer, then all you have to do is add the necessary attributes with the Symbol Builder. If you have an AutoCAD block with attributes, you can use the Symbol Builder to create an AutoCAD electrical block from the existing geometry, and convert the standard AutoCAD attributes to intelligent electrical attributes, thus creating a fully intelligent AutoCAD electrical symbol.

Let's begin by exploding a block that was previously created in AutoCAD. Then, start Symbol Builder (it's located under Misc. on the Tool Palette), and select the AutoCAD block, including the attribute text. The first page of the Choose Symbol Category dialog box contains selections for Schematic & Panel Layout Symbols.

The Choose Symbol Category dialog box within Symbol Builder.

In this example, we're building a schematic parent symbol, so select the Parent button. This launches the Schematic, Stand-alone or Parent dialog box. Here you can choose to create the geometry, or begin adding attributes to geometry that has already been created. In this case, we're converting text from plain AutoCAD blocks into AutoCAD electrical attributes, so select the Convert Text button.

This takes you to the Generic Text Entities dialog box. From here, select the Convert to AutoCAD Electrical Attributes button. This opens the next dialog, where you choose what attribute the text will become. In this case, let's assign Name to TAG1. Type in what you want the Tag Default to be (in this case, PB) and click OK. Then, assign MFR to Manufacturer. This takes you back to the Main Menu.

The Component Type dialog box.

Next, choose the Standard button, and the Component Type dialog box opens. Here you'll see a list of attributes that you can select from. Notice that the TAG1 and MFG attributes are grayed out, indicating that you have already assigned these attributes. Select an attribute by clicking the radio button to the left, and choose the Insert Attribute button. This lets you pick a point on the drawing to insert the attribute. As you place the attributes that you want to add, they are grayed out to indicate that you have already used them.

Adding attributes to a component.

Continue selecting and adding the attributes as needed. At the bottom of the dialog box is a button labeled More. Press this to go to the next dialog box, which contains more attributes; add these as needed.

Adding multiple attributes to a component.

When you are finished, press the Back button to return to the previous dialog box, or Back to Main Menu to go back two dialog boxes.

Choose Back to Main Menu.

You may continue to add more information, such as Wire Connection, Terminals, NO or NC info, Dashed lines and Rating info.

When you've finished adding all the attributes, select the WBLOCK button to create the block. You may choose to insert an instance of the new block at this time. You can insert the blocks that you create via Insert Symbol from file (Browse on the Insert Symbol Dialog Box), or you can add them to the Icon Menu.

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