Could someone please explain the difference between open -w %1 and impasc %1? I found out that impasc give me issues sometimes with short names and importing files, but open -w doesn't yet it does give me issues with units.
open -w is an old Labtalk command that you do not have anyway of specifying import options.
impasc is the new X function that allows full scripting control. Best way is for you to first use the Import Single ASCII menu command to open the dialog for impasc and adjust the settings so everything is working right, then you can choose "Generate Script" from the Dialog Theme popup menu to give you the script that you can then modify to use in your code.