EL3161 by Beckhoff

The EL3161 is an analog input terminal produced by Beckhoff as part of the EL EtherCAT Terminals series. Designed for distributed I/O architectures, the unit acquires a process voltage and sends the digitized value over the EtherCAT fieldbus. Within an automation cell, it clips onto a DIN rail next to other terminals, giving the controller direct access to precise voltage measurements from field transmitters or laboratory sensors.

The converter provides a 16-bit resolution, allowing small voltage changes to be represented accurately in the process image. A maximum measuring deviation of ±0.3% FS limits the total error across the operating temperature range. EtherCAT distributed clocks hold the sampling event to a jitter of less than 1 µs between network nodes. Simultaneous acquisition prevents phase skew when multiple EL3161 terminals are triggered together. The analog front end includes a 5 kHz input filter that attenuates higher-frequency noise before conversion, while an internal resistance above 200 k? minimizes loading on the connected signal source. Signals are measured against a single-ended ground reference, and a dedicated shield terminal can divert up to 100 mA of unwanted current. An 8-bit status field reports overrange conditions, synchronization states, and diagnostic information to the controller.

The terminal handles one analog input channel and supports field potentials up to 30 V between the signal and logic sides, making it suitable for low-voltage instrumentation circuits. Power feed-through on the rear blade is rated at 1 A, allowing downstream terminals to share the same supply rail without separate power wiring. The IP20 enclosure provides basic protection against contact with internal parts but does not protect the terminal from water, so cabinet installation is required. Its compact terminal format allows the module to be installed beside EtherCAT masters and other EL series terminals without requiring a separate remote enclosure.