ELX3202 by Beckhoff

The ELX3202 is a twin-channel resistance temperature detector input terminal produced by Beckhoff within the EL EtherCAT Terminals series. It connects directly to the EtherCAT I/O system to deliver temperature data to a controller without intermediary signal conditioning. Designed for use with Pt100, Pt1000, and KTY sensors, it converts sensor resistance into a digital value that can be processed in automation routines. By occupying only one terminal slice, the unit allows compact, distributed temperature acquisition on production machines and process skids.

Each channel accepts two-, three-, or four-wire sensing loops; this flexible wiring is indicated by the 2-/3-/4-wire connection method and permits precise compensation of lead resistance. Internal electronics draw their logic power from the E-bus at 5 VDC, while the galvanically isolated field circuit is limited to 12 mA of short-circuit current and 15 mW of maximum power. These parameters meet intrinsic safety requirements when the 24 V Ex supply is used. The open-circuit voltage at the sensor never exceeds 4.94 V, helping prevent excess energy from entering hazardous areas. A linear characteristic curve simplifies scaling because the raw resistance is converted directly into a proportional temperature word.

The terminal samples both differential inputs with a resolution of 0.1 °C/digit, and the measuring current remains below 1 mA, preventing self-heating of delicate probes. Absolute accuracy remains within ±0.3% of full scale across the stated temperature span, including converter linearity and reference drift. Converted values are delivered to the controller as a 2 × 32-bit RTD process image, so no additional data packing is needed. The housing has an IP20 protection rating for installation in control cabinets, and status LEDs report channel conditions and sensor faults.