How to Convert MapInfo TAB to Microstation DGN (GIS to CAD)

Introduction

This tutorial will show you how to convert a MapInfo TAB (MITAB) (*.tab) file to Bentley Microstation DGN (*.dgn) format using FME. Learn how to split the output data into MicroStation levels based on a category for each zone. Also, learn how to set MicroStation tags and change the seed file from 3D to 2D.

Video

This video was filmed using an older version of FME. The interface may have changed but the concepts are still the same. 

Step-by-Step Instructions

1. Start FME Workbench

In Windows, this is found under Start > All Programs > FME Form > FME Workbench. Once FME Workbench is open, click New to start a new workspace. 

2. Add a Reader (Source Data)

In the new workspace, click Add Reader on the top menu bar. 

In the Add Reader dialog, set the Format to MapInfo TAB (MITAB), then for Dataset, click on the ellipsis and browse to the Zones.tab dataset that can be downloaded from this article. Click OK to finish adding the reader.  

3. View Source Data

A Zones reader feature type will appear on the canvas. Single-click to open the mini menu, then click View Source Data to view the data in Visual Preview.

In Visual Preview, we can see all of the zones in the Vancouver area and their categories. 

4. Add a Writer (Output Data)

On the top menu bar, click Add Writer. 

In the Add Writer dialog, set the Format to Bentley MicroStation Design (V8), then browse to a location to save the Dataset. Before we can finish adding the writer, we need to set the Tags and Seed, click Parameters. 

First we will need to change the Seed File (V8 only) from a 3D seed to a 2D seed. Click on the ellipsis, and select seed2d_ft_v8.dgn. Then set Write tags to Yes. Click OK twice to finish adding the writer. 

FME comes with several seed files located in the install directory \FME\design\. For more information on the Bentley MicroStation Design writer, see the documentation. 

5. Modify the Output (Writer Feature Type) Properties

After clicking OK a Feature Type dialog will appear. We want to utilize an attribute name for the Level Name, so we will need to connect the writer feature type to the existing workflow. Click OK to accept the default name of Level1 for now.  

Connect the Zones reader feature type to the Level1 writer feature type. 

With the writer feature type connected, double-click on it to re-open the parameters. In the parameters, click the drop-down arrow next to Level Name, expand Attribute Value, and select ZoneCategory. Each ZoneCategory will be written to a separate level in the .dgn file. 

Since we are defining the zone category by the level name, we no longer need it written out as a tag. To remove ZoneCategory, switch to the User Attributes tab (1), then change the Feature Definition to Manual (2). Now we can manually modify the output attributes. Click on the ZoneCategory line to highlight it (3), and click on the minus sign ( - ) at the bottom to remove it (4). Click OK once it has been removed to close the parameters. 

6. Run the Workspace

After changing the parameters, notice how the writer feature type is <@Value(ZonesCategory)>, and there is only a single attribute of ZoneName.

Run the workspace by clicking on the green play button. This carries out the translation.

7. View the DGN File in a MicroStation Viewer or Visual Preview

After the workspace has finished running, open the data in Visual Preview, and note the different levels within the file. 

The data can also be viewed in a CAD viewer such as MicroStation Viewer to see the different levels for each category. 

Data Attribution

The data used here originates from open data made available by the City of Vancouver, British Columbia. It contains information licensed under the Open Government License - Vancouver.