As long we the receiver is outputting a RKT signal, FW Mobile to receive that automatically. Within FW Mobile go to the file menu and select GPS Status. The Quality number showing should be a 4 or 5 if receiving the RTK. There is no setting in FW Mobile to tell it to search for the GPS signal, if the receiver is outputting FW Mobile will receive. There is, however, a setting to only log when receiving the RTK by going to the File Menu - GPS settings -Quality Tab, and change the Min. GPS Quality to a 4 or 5 your choice. Reminder this setting does not help you receive that signal only control for logging that signal quality.