The disclosure refers to a method for controlling operation of a user control terminal of an agricultural machine, comprising providing an agricultural machine having a tractor and an implement trailed by or carried on the tractor; providing a user control terminal on the tractor, the user control terminal configured for receiving user input through a control knob; operating the control knob in a first knob mode of operation, comprising receiving a first function control user input through the control knob; in response to the receiving, generating first function control signals for a functional element of the implement in a control unit functionally connected to the functional element; operating the functional element according to the first function control signals; receiving a second function control user input through the control knob; in response to the receiving, generating second function control signals for the functional element of the implement in the control unit; and changing operation of the functi
