Recently I had a few questions from customers about the Symbol Builder and how the attribute templates work. They were trying to add a new category of symbols and running into a few problems.
When you first start Symbol Builder you get a dialog box with lots of options. The ones I want to talk about today are the Symbol and Type drop-down lists.
What you pick on these 2 drop-downs control which attributes are available, and some default values, when you get into the Symbol Builder environment.
You can always add attributes and change values, but starting with a good attribute template can save a lot of time when creating new symbols.
But, how does it do this and how do I add my own values to these drop-down lists?
AutoCAD Electrical uses a set of library symbols, that I will call attribute templates, to accomplish this. Each library symbol has the default attributes for a certain type of symbol. For example, if it is an attribute template for a schematic parent, it will have the TAG1, while an attribute template for a schematic child will have TAG2.
Attribute templates follow the naming convention, AT_{symbol}_{type}.
The {symbol} value appears in the Symbol drop-down list.
Certain codes are recognized by Symbol Builder, such as HP for Horizontal Parent or HC for Horizontal Child. Or you can use the full text, such as "Horizontal Parent".
For example, if you wanted to add some attribute templates for pre-built PLC modules, you could have a group of attribute template symbols that started with AT_PLC_. As soon as I add a library symbol (in my project's schematic library path) using this naming convention, it shows up in the drop-down.
The {type} value from the symbol name appears in the Type drop-down list.
The values in the Type drop-down are filtered by what you select in the Symbol drop-down. In this example I selected Horizontal Parent, so the drop-down includes symbols named AT_HP_*. You can see how the list of library symbols matches up with what is shown in the list. I will talk in a minute about where the descriptions comes from. But, first let's add a Type entry for our new PLC symbol category.
Let's say I want to add a template for a PLC symbol with 4 I/O points. I could name it AT_PLC_4IO. As soon as I create the symbol and restart Symbol Builder, it shows up in the Type drop-down.
If I add more AT_PLC_* templates, they also show up.
But, notice they don't have descriptions like the others. To have a description show up here, you need to map each Type abbreviation (4IO, 6IO, 8IO) in the _FAMILY_DESCRIPTION table of the catalog database, i.e. default_cat.mdb.
Then, the descriptions show up in the drop-down.
Of course, for this to be useful you need to add the appropriate attributes and default values to your attribute templates. Knowing what attributes need to be on a certain symbol type is a topic for another day. Until then, you can start with the Help topic, About Schematic Attributes, to get information about the various types of schematic attributes. And to learn more about Symbol Builder attribute templates, see the Help topic To Create a Symbol Builder Attribute Template.
- Pat Murnen