Cube67 is a modular, distributed I/O system that uniquely combines protection category IP20 and IP67 – plug-fitted, robust and fully encapsulated. Starting from the bus coupler, the I/O layer spreads radially throughout the application. The individual system components are connected in a rational and uncluttered manner via hybrid cables that bundle both communications and power. The design focuses on optical debugging. A transparent ring running around the 20 x 20 x 20 mm plug provides the optical signal. If a fault occurs, the LED at the interface to the defective module lights up for rapid identification.