AutoCAD Key-ins in MicroStation

AutoCAD Key-ins in MicroStation

Does your organization have users that are new to MicroStation? Do you have a user that is more familiar with AutoCAD? Is there anything to help a new user acclimate to MicroStation more easily? As a long-term user, it is easy to forget what it was like when you first began using an application.

Bentley has long been an advocate of “interoperability”. In MicroStation, this concept has proven itself through an ever-expanding list of file formats that are supported for opening, editing, referencing, and conversion ranging from native support of shape files (.shp) to the ability to work with point cloud data. Interoperability however, is not limited to the support of file formats. To assist in making the transition from Autodesk to Bentley applications, or work in both environments, the ability to use AutoCAD commands in MicroStation is available. Support for these commands is provided through the ability to use AutoCAD style key-ins and Program Parameters (.pgp or PGP) files.

Using AutoCAD Commands in MicroStation

MicroStation contains a set of key-ins that provide a user, familiar with AutoCAD, with the ability to set system variables and activate equivalent MicroStation commands through the Key-in window using familiar AutoCAD command syntax.

Key-ins can be entered in several different ways including:

  •  DWG prefix: Key in the DWG prefix, followed by the AutoCAD command.
  • Command prefix: Key in the command prefix, followed by the AutoCAD command.

Both of these methods require the use of a prefix, followed by the AutoCAD command that is to be activated. The prefix is required to differentiate between a standard MicroStation key-in or an AutoCAD key-in.

To enter a key-in command, you must first open the Key-in window. In the Drawing Workflow this can be activated through the Primary ribbon group of the Home tab.

 An alternate method of accessing the Key-in window is by pressing Enter on the keyboard with the input focus set to Home. This will open the Key-in window as a pop-up. The input focus can be seen in the status bar of the MicroStation application window.



The Key-in window is broken into three basic parts:

  • The key-in field
  • The key-in list
  • Key-in history


The Key-in window can be used “as is”, resized, or docked in the MicroStation interface.


The DWG Prefix

Key-ins in MicroStation are similar to those used in AutoCAD. Since MicroStation supports both, a prefix is used to tell MicroStation that an AutoCAD command is being entered. This is a simple process, with the DWG prefix preceding the AutoCAD command.

To draw the MicroStation equivalent of a Polyline, key-in DWG PLINE and press Enter. The SmartLine command is activated.


 Use of the Key-in window can also be helpful in learning what the MicroStation commands actually are.

 Note: Key-ins are not case sensitive.


The following table illustrates several examples of using the DWG prefix:

AutoCAD Key-in

Tool Description

Similar MicroStation Tool or Key-in


Places a chain of connected line segments and arc segments.



Places an arc.



Defines hatches.



Copies elements.



Breaks up elements into smaller components.


Note: For additional information and a more comprehensive list of supported AutoCAD key-ins, in Help, see: Supported AutoCAD Key-ins.

The Command Prefix

MicroStation also provides for the use of a “command prefix” when using an AutoCAD command. This prefix can be used rather than typing DWG each time an AutoCAD command is input. The default command prefix is the backslash character (\). To activate the polyline command equivalent, key in \pline in the Key-in window:

The command prefix is defined by the configuration variable MS_DWG_COMMANDPREFIX. The variable can be set to a character or string of characters that can be used as a shortcut to the AutoCAD commands. Avoid using a prefix that could be interpreted as a MicroStation key-in. For example, using AC as the prefix conflicts with the MicroStation key-in for ACTIVE CELL. The space character may be a convenient prefix due to its keyboard location.

 Note: When defining a prefix, enclose the definition within double quotes to avoid having it misinterpreted (i.e. “ACAD”).