Product Description:

The EL3122 is a two-channel analog input terminal produced by Beckhoff for the EL EtherCAT Terminals series. Serving distributed control systems, the unit digitizes 4–20 mA process signals from transmitters used in pressure, flow, or temperature loops. By integrating current conversion at the I/O node, it shortens wiring runs and simplifies signal conditioning inside industrial automation cabinets and on the machine frame.

Each channel accepts 4–20 mA signals, and the module offers two independent inputs, so separate loop isolators are unnecessary. A 16-bit converter provides 65,536 discrete steps across the span, supporting fine resolution even when ranges are narrowed in software. The module uses simultaneous acquisition, which maintains the time correlation between channels for differential or redundancy checks. An internal low-pass stage with a 5 kHz limit attenuates out-of-band noise before sampling. Up to 10 V of common-mode potential can exist between the sensor loop and system ground, while the differential ground reference further rejects external interference. Captured data are delivered to the EtherCAT master through a process image consisting of two 16-bit values and corresponding status bytes.

Overall measurement accuracy is held within ±0.5% FS, which is sufficient for most analog utility measurements in HVAC, water, or material-handling systems. The channel circuitry allows a drive current of up to 40 mA, supporting reliable open-circuit detection or loop excitation even with long cable runs. The housing is rated IP20, requiring placement in a protected enclosure while permitting direct field wiring. The verified operating temperature range is -25 to +60 °C, while storage from -40 °C to +85 °C helps prevent damage during transportation. The 12 mm-wide housing snaps onto a 35 mm DIN rail in accordance with EN 60715. Its locking mechanism secures the terminal beside other EL-series modules in the I/O assembly.