The PSCAD X4 release represents a vast transformation in program architecture. It is also a prudent point at which to continue unfettered by old operating systems, Fortran compilers, and older PSCAD versions. This latest version allows you to import *.psl and *.psc format project files that were last saved in PSCAD v4.2.1 only, and it is not backwards compatible: In other words, once your projects have been migrated into X4, they cannot be exported back to the older formats.
NOTE: If you are a PSCAD V3 user, and you want to import your projects into X4, you must first import, test and save your projects in PSCAD v4.2.1. PSCAD V2 users will of course need to do the same.
This chapter discusses topics regarding the migration of projects from older versions into the latest PSCAD version. For more information on migrating user-defined code and other EMTDC related issues, see the section entitled Converting V2 Fortran Files in Chapter 10 of the EMTDC Manual.