.csv files are opened directly in JMP. They are treated as just another file to open. So if you are running interactively, you just go to
File==>Open
and then navigate to the .csv file you want to open, and then open it
To save it as a JMP file, just go to
File==>Save As
In JSL the following is the code:
Names Default To Here( 1 );
dt = Open( "<path and file name.csv>" );
close( dt, save( "<path and file name.jmp> " ) );
Documentation for the interactive open and save is in
Help==>Books==>Using JMP
Documentation for the JSL is in
Help==>Scripting Index
or
Help==>Books==>Scripting Guide
Jim