Beckhoff KL3122 IO Module

Beckhoff KL3122 is a compact two-channel analog input terminal for the K-Bus that digitizes 4–20 mA current signals with 16‑bit resolution (default 15‑bit) and transmits the results galvanically isolated to the host automation device. The two input channels are differential and share a common internal reference, enabling robust measurement in electrically noisy environments. Powered from the K-Bus (no separate supply required), the module includes Run LEDs to indicate data exchange and Error LEDs to signal overload conditions, and it can detect wire breaks or overloads, reporting these statuses over the K-Bus. Technical data specifies 2 inputs; signal current 4–20 mA; differential input; internal burden resistor 50 Ω (burden: 60 Ω plus diode drop); and a configurable 50 Hz filter. This KL3122 device is designed for sensor applications using 4–20 mA loops, making it suitable to pair two sensors in a single, space‑saving terminal. It is part of Beckhoff’s KL3xxx family of analog input terminals and is intended for use with Beckhoff bus couplers to form a modular I/O rack in industrial automation systems.