No variable however you can accomplish this in a couple different ways.Originally posted in cdnusers.org by Trykon
1. Use a startup script that will set the drawing units, along with other items you find helps start out a new drawing such as setting colours etc.
You can then start Allegro using the -s (script command) e.g.:
allegro design -s startup_script (Where s"tartup_script" is the name of the script you recorded)
Using the variable "script_startup" found in the Ui category of the Preferences editor specify the script. See the Preferences editor for a description and use of the variable.
2. Import a techfile that contains the units that you need. You can also use the techfile facility to setup the stackup.
o Create a new drawing with the units and stackup desired. You can create as many as you like for different units, stackup, constraints etc.
o File > Export > Techfile...; Add a name and select "Export"
o Start a new drawing
o File > Import > techfile...; browse to the techfile you need and select "Import".
Hope this helps