EL3101 by Beckhoff

The EL3101 is a Beckhoff analog input module from the EL EtherCAT Terminals series. It converts voltage signals from field devices into digital process data so a controller on the EtherCAT network can supervise and log continuous process variables. Installed on a DIN rail alongside other terminals, the unit provides isolation between sensor wiring and the backplane while allowing the host PLC to sample one differential channel and coordinate it with motion, temperature, or drive information in real-time automation tasks.

The terminal accepts a bipolar range of ±10 V and digitizes the waveform with 16-bit precision. A configurable analog filter limits the input bandwidth to 5 kHz, protecting the delta-sigma converter from aliasing when high-frequency noise is present. The measurement front end provides an input resistance greater than 200 k?, so it does not place an excessive load on transducers with limited drive capability. The permissible common-mode range is limited to 35 V, helping prevent damage if line potentials drift relative to logic ground.

The terminal performs simultaneous conversion, allowing time-aligned sampling when several EL series input cards are synchronized through the built-in distributed clock system. The signal contacts can carry up to 40 mA without overheating, and the total linearity and gain error remain within ±0.3% from 0 to 55 °C. The IP20 protection rating is suitable for cabinet-mounted equipment where access by fingers and solid objects larger than 12 mm must be prevented. One analog channel is provided and uses differential measurement to reject interference caused by ground potential differences. Distributed clock timing keeps the reading synchronized with outputs and other process data elsewhere on the EtherCAT network. Nonvolatile storage retains scaling parameters after a power cycle, so previously saved adjustments do not need to be entered again when the system restarts.