Synchronizing External Parameters

This task will show you how to synchronize external parameters between a drawing and another document.
Open the ExtParamPart.CATPart document. As you can see, a length parameter has been created on the part and is displayed in the specification tree. Its value is 10mm.

For further information on creating parameters for a part, refer to Working with Parameters section in the Knowledge Advisor User's Guide.

Open the ExternalParam.CATDrawing document and tile the drawing and the part windows horizontally. To do this, click Window > Tile Horizontally from the menu bar.


  To make sure those two parameters are associated:
  1. Go to Tools > Options > Infrastructure > Part Infrastructure

  2. In the General tab, select Keep link with selected objects, then click OK.

For further information on the General tab, refer to the Part Infrastructure for Knowledgeware Applications section in the Knowledge Advisor User's Guide.


First of all, you are going to create a new parameter in your drawing based on the part's parameter.
  1. In the Knowledge toolbar, click the Formula icon .

  2. Select Length in the combo box.

  3. In the Formulas dialog box, click the New parameter of type button.

  4. Position the cursor in the value field and click the Add Formula button.

  5. In the Part Specification Tree, select the Length parameter.
    `External Parameters\Length.1` is displayed in the Formula Editor dialog box.

  6. Click OK to close the Formula Editor dialog box.
    In the Formula dialog box, you can see the parameter's value is 10mm.

  7. Click OK to create the parameter.
    The Length parameter is displayed in the drawing specification tree as an external parameter.

  To propagate changes between the part and the drawing:
  1. In the Part specification tree, double-click the Length.1 parameter.

  2. Change the value from 10 to 20mm.

    Back in the Drawing specification tree, you can see a red cross is displayed on the parameter. It means it needs to be updated.

  3. Right-click the Length parameter.

  4. Select Drawing > External Parameters > Length.1 object > Synchronize.

    The parameter is updated and a green diamond is now displayed on the parameter showing it has been synchronized.

You cannot use the Update icon to refresh the parameters. You have to synchronize them individually.
If you create a text on the drawing that references the external parameters thanks to the Attribute link option, updating the drawing will synchronize the parameters.