KL3444 by Beckhoff

The KL3444 analog input terminal is manufactured by Beckhoff within the KL Analog Input Modules series. The terminal converts process currents into digital data so that a host controller can monitor field devices such as pressure transmitters or flow meters. By integrating multiple channels in a 12 mm housing, the unit saves rack space and simplifies signal acquisition in distributed I/O stations.

Its channel group is organized as 4 x 16 Bit input words, so every one of the four measurement points delivers a full two-byte data set to the bus. Internally each converter operates with a resolution of 12 Bit, allowing step sizes of roughly 5 µA across the specified current range of 0-20 mA. The terminal expects the field sensor and its return lead to be wired in a 2-Wire configuration, bringing analog common and sense current onto adjacent spring terminals. To protect upstream wiring, the electronics respond to abnormal load by shutting down the affected channel because overload detection is present. The power feed-through contacts can conduct up to 10 A, which means several neighboring terminals can be looped without separate supply cables. An enclosure rating of IP20 restricts installation to control cabinets that offer basic dust protection.

Transient disturbances on the sensor lines are tolerated up to 30 V DC, so most industrial control voltages will not damage the input stage during mis-wiring. The compact housing, defined at 12 mm x 100 mm x 68 mm, aligns with other Beckhoff terminals and supports high channel density on DIN rail. Operating power for the measurement circuitry is drawn Via K-bus, so no separate auxiliary supply needs to be cabled, further reducing installation time and panel complexity.