V7 File Migration and Support

MicroStation opens design files from all previous editions. When you open a V7 design file, you have the option of either upgrading the file to V8 DGN file format or opening it read-only. If you want to work with V7 design files in the current version of MicroStation but need to maintain backward compatibility, you have two choices:

Upgrade newly opened V7 design files to the new format, but save them when done making changes as V7 files in which the graphic representation is maintained.
Configure MicroStation to operate in V7 workmode, in which MicroStation permits the opening of V7 design files for write access but disables functionality that is not backward-compatible.

Options for Saving V8 DGN Files as V7 Design Files

You can use the Save As V7 Options dialog to map MicroStation V8 DGN file format data constructs, such as levels above 63, fonts that are new to MicroStation, cells that are too large or have names that are too long, etc., to V7 analogues, and to select other options that influence backward compatibility.

Note: When saving a MicroStation V8 DGN file in V7 format, MicroStation does not save "live" nested reference attachments to the resulting V7 file.

Setting Up and Using V7 Workmode

V7 workmode operation differs from other MicroStation V8 workmodes, and for that matter, from previous editions of MicroStation, in a fundamental way:

CAUTION: When operating MicroStation V8 in V7 workmode, it is necessary to manually save changes to the open DGN file by choosing File > Save.

The following capabilities are disabled in V7 workmode:

view group creation
level creation
model creation
3D references in 2D design files
reference associations
references to models created in V8 DGN files
references to models created in DWG files

You cannot use V7, or other pre-V8 cell libraries in V8 using the V7 format, even in V7 workmode. Once you attach a cell library in a V8 design session, it is automatically upgraded to V8 format and a backup is saved to MS_BACKUP (or MS_TMP, if MS_BACKUP is not defined).

To continue using a cell library with a V7 format, you need to maintain the cell library in V7, and upgrade a copy to V8 as needed. This does not affect cells placed in a DGN file, which will save to V7 files successfully.

Batch Migration from V7 to V8 Format

You can use the Batch Converter, to upgrade a set of V7 design files and/or cell libraries to V8 DGN format.

To explicitly specify the working unit setup for upgraded files, you must specify the desired working units in a text file. During the upgrade, if the unit labels in a file being processed are identical to those in a custom unit definition, MicroStation V8 creates the V8 DGN file with the specified units.

For the syntax and examples of custom unit definitions, see the sample unit definition file, units.def, which is installed in the ..\Default\Data\ folder in MicroStation's program directory.

The configuration variable MS_CUSTOMUNITDEF defines the location of the unit definition file. As delivered, MS_CUSTOMUNITDEF is set to the installed sample file, units.def. All of the unit definitions in that file are on lines that begin with the # character — that is, "commented out" — so even if you do not modify the file or redefine MS_CUSTOMUNITDEF, none of the sample unit definitions are applied by default.

Note: If a unit from the units definition file conflicts with one of the standard MicroStation units, the unit from the definition file is used.