Originally Posted by
giggitygiggity
Take a look at the architecture diagrams in FCOM 27-10-20 Yaw Control and FCOM 32-20-10: Nose Wheel Steering Description.
Rudder Trim controls the rudder through the trim switch or autopilot via the FACs. It's not linked to the NWS system. So adding rudder trim results in a rudder deflection to keep you straight on the taxiway if you're testing it to confirm an offset.
NWS is actuated via the Steering Servo Valve commanded by the BCSU through the Y HYD system (or the green on very old aircraft). That's only controlled by the tiller, else the rudder pedals or the autopilot via the ELACs.
Yaw Control architecture shows the rudder trim moves the rudder pedals via the feedback circuit and the rudder pedals move the NWS via the ELACs so wouldn’t that suggest the rudder trim will move the NWS via the rudder pedals?