EL2034 by Beckhoff

The EL2034 is a four-channel digital output module from Beckhoff that belongs to the EL EtherCAT Terminals series. As an EtherCAT slave, it switches 24 V DC actuators directly from the fieldbus process image, allowing PLCs to energize solenoids, indicator lamps, or small relays within distributed control cabinets. The terminal draws its logic power from the system E-Bus, so only the load supply has to be wired through the front connector. This arrangement reduces the amount of separate power wiring required for the control electronics.

This module operates at a rated output voltage of 24 V DC, matching the common control level used in machinery panels. Each channel can source up to 2 A per channel, so resistive heaters, inductive coils, or lamp loads can be switched without an interposing relay. The control electronics consume only 120 mA from the E-Bus, keeping their demand on the upstream power supply low. Typical energization takes 40 µs, which keeps the delay between the PLC command and field actuation short. The magnetic energy released during inductive switch-off is limited to less than 1.7 J per channel by integrated transient suppressors. In addition to resistive devices, the terminal supports inductive and filament lamp loads, allowing it to operate several common load types.

Four output bits and four diagnostic bits are mapped to the process image, providing per-channel feedback about switching states and fault conditions. When enabled, the terminal detects short circuits and open circuits, and it blocks the affected output when a corresponding wiring fault is detected. Reverse-voltage protection helps prevent damage if the load supply is connected incorrectly. The quiescent load path draws only 14 mA, excluding the current used by connected loads at the power terminals. Typical turn-off time is 200 µs, allowing coils to discharge before they are energized again. The housing has an IP20 protection rating, making the terminal suitable for installation inside a protected control cabinet. The terminal occupies one EtherCAT address in the control system.