Compare your "Main Version" against the latest version listed on Alpine’s official support page. As of the last major release, the most current stable version is (though you should always verify directly on Alpine’s website).
If your 702D has the optional Nav module (usually HCE-C213D or similar), map updates are separate, paid, and require an SD card from Alpine. Users say these are expensive and infrequent. alpine ilx-702d software update