EL2042 by Beckhoff

The EL2042 is a two-channel digital output terminal produced by Beckhoff for the EL EtherCAT Terminals series. Within an EtherCAT I/O node, it switches 24 V field loads using the E-bus and power contacts, enabling actuators, indicator lamps, or solenoids to be operated under PLC control. The terminal occupies a 12 mm slice on a DIN rail assembly and maps each output into the controller's cyclic process image, making it suitable for distributed automation where compact solid-state switching is required.

The output circuitry uses a nominal supply of 24 VDC. Each channel can continuously source up to 4 A per channel, while the combined power contact path permits a maximum of 8 A when both channels are used simultaneously. Internal logic draws only 120 mA from the E-bus, so backplane loading remains low even in large terminal strings. The module provides 2 discrete output bits to the process image, allowing direct bit-level control from the EtherCAT master. Ohmic, inductive, and lamp loads are supported, and energy stored in inductive devices is returned through integrated freewheeling circuitry to protect the switching transistors.

For field wiring, current draw from the power contacts is 13 mA plus the load current, so quiescent consumption remains minimal when the outputs are idle. The housing conforms to the IP20 protection class, providing finger-safe terminals while requiring installation inside a suitable cabinet. Typical actuation occurs within 40 µs after the control bit is set, and the load is de-energized within 200 µs, supporting high-speed sequence control. Reverse-voltage protection helps prevent damage from an incorrectly wired 24 V supply, while internal diagnostics report short circuits through the bus. A deterministic two-bit output image simplifies cyclic scanning and provides predictable update times in synchronized EtherCAT networks.