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 functional element for operating the functional element according to the second function control signals； receiving a request user input for changing knob mode of operation for the control knob； and in response to the receiving, operating the control knob in a second knob mode of operation, the user control terminal prevented from receiving function control user input through the control knob in the second knob mode of operation. Furthermore, an agricultural machine is disclosed.
