OmniRig is essentially a serial port sharing utility. It allows multiple pieces of software (Logging programs, software for RTTY, PSK31, rotator control, etc.) to interact with a transceiver for CAT control but it only only works with applications specifically designed to use OmniRig. Also, OmniRig only supports certain transceivers.
According the Omnirig website, it is compatible with your Kenwood 480SAT. The website also mentions being compatible with the Elad Elad-FDMSW2.
There is a discussion group on Yahoo dedicated to OmniRig and it's author's other software products. I suggest you take your question there: https://groups.yahoo.com/neo/groups/dxatlas_group/info