EL3004 by Beckhoff

The EL3004 is an analog input terminal produced by Beckhoff for the EL EtherCAT Terminals series. Installed on a DIN rail with adjacent I/O slices, the module converts field-level voltage signals into digital data that an EtherCAT controller can analyze for feedback, monitoring, or closed-loop regulation in automated machinery. A unique slot address is assigned through the E-Bus backplane, allowing compact voltage acquisition for drives, temperature converters, and sensor arrays on manufacturing equipment.

The terminal provides 4 analog inputs that accept bipolar signals up to ±10 V. Each channel is digitized at 12 bits, providing 4,096 steps across the input range. An input filter of 1 kHz attenuates higher-frequency noise, and measurement deviation remains within ±0.3% FSV from 0 °C to 55 °C. The front end has an internal resistance greater than 130 k?, minimizing sensor loading. Dielectric strength is 30 V, so external overvoltage protection may be required. The process image provides 2 bytes of status data and 2 bytes of value data for each channel. The electronics draw power from the E-Bus, and distributed clock functionality is unavailable on this model.

Field wiring uses a 2-wire scheme, and the channels share a single-ended ground reference that simplifies connections to transducers with common return lines. The conversion sequence uses a multiplexed method, cycling through the inputs so that only one channel is sampled at a time. Screwless push-in clamps are protected to IP20, making them suitable for typical cabinet environments. The power contacts are connected through the side of the module, allowing upstream terminals to pass the 24 V supply without interruption. The isolation limit restricts the module to extra-low-voltage circuits. Time stamping can be implemented in the EtherCAT master when deterministic sampling is required.