Version 2 has been out for several years and you almost certainly are running it already.
If you go to >Help >About you will get a screen that shows Version 4.2.0. x x x x where
the 4 means means the product is Mach4, the 2 means version 2 in the Mach4 series,
0 is the sub-version, and x x x x is the build number of the software that you are running.
If you are not having any problems, there is no need to update your software.
There are production releases that are available on the Download page for Mach4, and
also beta versions on a separate FTP server.
There are normally no update charges for Mach software within a product series,
i.e. product 4 for Mach4.