Scan does not work the same on all players. On some players, the scanVideo command starts the scan, and a stopVideo must be issued to stop it. On other players you must repeatedly reissue the scanVideo command to keep the player scanning. After scanVideo has been called, "the result" will contain
"only once" if scanning will continue until a stop is issued.
See the example control panels in the Videodisc Stack for specific HyperTalk code to perform proper scanning.