IE2021 by Beckhoff

The IE2021 is an eight-channel extension box produced by Beckhoff for its IE Extension Box Units series. It distributes switched 24 V control power from an upstream EtherCAT or similar coupler to field devices such as valves, contactors, or pilot lamps. By housing protected high-side switches in an IP67 enclosure, the unit allows digital actuation equipment to be mounted directly on the machine frame, shortening sensor and actuator wiring runs and preserving cabinet space for higher-level controllers.

Each output operates at a nominal bus voltage of 24 VDC and can deliver up to 2.0 A of load current to resistive, inductive, or lamp loads. Internal electronics draw only 30 mA per channel, so the module places a minimal burden on the auxiliary supply. The box provides 8 dedicated output bits to the PLC, creating a one-to-one mapping between the field terminals and the process image. Output data and diagnostic flags are galvanically isolated from the bus master. Field wiring leaves the module through one 4-pin M8 socket, while incoming 24 V power and ground enter through a matching four-pin M8 male plug. Reverse-polarity protection at the power feed prevents damage if the supply leads are swapped.

The eight channels share a combined current capacity of 4 A. Each channel also provides a 24 V sensor supply rated at 0.5 A per channel for proximity switches or encoders. If a wiring fault occurs, the output stage limits the fault current to 4.0 A. The short-circuit-proof switching elements recover automatically after the fault is cleared. Signals are connected through the front-mounted M8 screw-in sockets, which provide vibration-resistant terminations for mobile or high-impact machinery. The protected outputs and sealed connections permit installation near field devices without separate terminal blocks.