A plastics processing machine, particularly an injection molding machine, with an operating unit, a machine controller, and a subsystem having its own dedicated control unit is described. The machine controller and control device each generate a screen display and can be operated via the screen display. The operating unit is connected or can be connected for data transmission to both the machine controller and the control unit. Both of the machine controller and the control unit can be monitored and controlled by reproducing the original screen output from the machine controller and the control unit on the display screen of the operating unit, where new information can be entered. The information entered on the display screen of the operating unit is then transmitted back to the corresponding controller or unit associated with the reproduced screen display where the information was entered.