Abstract: A reel motor (1) for a driven conveyor roller has a stator (11) that is surrounded by a stator housing (10). A rotor (12) drives a rotor shaft (13). A tubular external housing (30) runs around the stator housing (10) at a distance in the circumferential direction. A cooling duct (20) is fluidically connected to an interior of the stator housing (10) holding the stator (11). The cooling duct 20 is formed between the external housing (30) and the stator housing (10). An impeller wheel (14) is secured to the rotor shaft (13). The impeller wheel generates a cooling air flow (K). The interior of the stator housing (10) and the cooling duct (20) determine a closed cooling circuit. The cooling air flow is guided through the closed cooling circuit.

Abstract: A control unit is controlled by a computer having a reset input. A circuit configuration protects the operation of the control unit by placing a signal at the reset input for restarting the computer in the event of a malfunction. The circuit configuration includes a first register into which a predetermined bit pattern is written in read-only fashion; a second check register in which a single defined bit is set at a time after individual program routines have been executed; a counter timer; and a comparator connected to the first register, to the second check register and to the counter timer, for comparing contents of the second check register with contents of the first register and outputting a reload signal for reloading the counter timer if the contents match.