Is this another student project? I presume you are going to use the serial port. If you set it in host link mode, then the Omron host link commands are used for communication. Here is a link to the Omron manual with all the codding information you will require http://oeiweb.omron.com/Home.shtm
Unfortunately the document library was unavailable when I tried to get the exact address for you. Just go to the above, select documant library, then select PLCs and then the manual for the CV1000.