KL3022 by Beckhoff

The KL3022 is a two-channel analog input terminal produced by Beckhoff within the KL Analog Input Modules series. It converts voltage signals from field sensors into digital data for Bus Terminal I/O systems, allowing a PLC to monitor process variables such as pressure, position, or level. An appropriate bus coupler connects the terminal row to the selected industrial network and transfers the acquired values to the controller. Direct modular signal acquisition on the DIN rail reduces long wiring runs and supports distributed control architectures in industrial automation.

The terminal's conversion path uses two 16-bit sample registers, with one register assigned to each input channel. The controller reads these registers and interprets the transmitted data as signed values for subsequent processing. The single-ended inputs share an internal ground reference, which simplifies sensor connections but requires careful shielding in electrically noisy cabinets. The module provides two independent channels, allowing two analog variables to be acquired without occupying additional terminal positions. Raw data are transferred to the controller with an application resolution of 12 bits, providing suitable granularity for temperature, pressure, and flow monitoring. The terminal receives its logic power through the K-bus, so separate power wiring is not required for its internal electronics.

The housing measures 15 × 100 × 70 mm, allowing two analog input channels to fit within a narrow terminal-row footprint. Installation is tool-free because the terminal snaps onto a 35 mm DIN rail, where the locking mechanism secures the housing and the internal contacts connect it to adjacent bus terminals. The enclosure has an ingress protection rating of IP20, making it suitable for installation inside a closed indoor control cabinet. The narrow housing helps conserve rail space when several analog and digital terminals are installed together. Spring-loaded connection points support orderly field wiring, while the modular terminal format allows channels to be positioned near the sensors they monitor. Shielding and grounding practices should account for the common reference used by the single-ended input circuit, particularly when signal cables run near motors, contactors, or variable-frequency drives.