EL4018 by Beckhoff

The EL4018 is an analog output module manufactured by Beckhoff within the EL EtherCAT Terminals series. Designed for distributed control cabinets, the terminal converts digital setpoints from an EtherCAT master into eight voltage channels that actuate drives, proportional valves, or other process hardware. By attaching to the standard terminal stack, it expands a machine's I/O map without requiring a separate standalone interface, making it a compact component for deterministic industrial automation tasks.

The module provides 8 single-ended outputs that share a common reference and are updated by a multiplex sampling circuit. Field devices receive power from a 24 VDC supply delivered through the power contacts, while internal words are exchanged as an 8 × 16-bit AO data block in the process image. Each channel uses a digital-to-analog converter with a 12-bit resolution, providing 4,096 discrete output levels across the available voltage range. When EtherCAT distributed clocks are active, the output timing provides an accuracy of less than 100 ns relative to network events, supporting synchronized multi-axis motion. The electronics receive their operating power solely from the E-bus. The common ground reference helps maintain consistent output behavior across the channels.

The terminal has an E-bus current draw of 100 mA and draws a typical 50 mA through its power contacts. Each output supports resistive or active loads with a load resistance below 150 ? while remaining within the applicable voltage range. Across the full operating temperature range of 0 to 55 °C, the module has a maximum overall error of ±0.1% FSV, supporting predictable output accuracy under varying cabinet temperatures. Installation uses a standard 35 mm DIN mounting rail, allowing the terminal to connect directly to adjacent EtherCAT modules. The enclosure provides IP20 protection against finger contact and solid objects larger than 12.5 mm, but it does not provide protection against water. The multiplex sampling system refreshes one channel at a time, while distributed-clock synchronization maintains consistent timing across the output set.