BECKHOFF KL1872 16-Channel Digital Input Terminal 24 VDC Flat-Ribbon Cable

Product Overview

The KL1872 (KL1872) is a high-density 16-channel digital input terminal designed for the Beckhoff Bus Terminal system, specifically engineered for space-constrained applications and rapid mass-termination. Unlike standard terminals, the KL1872 utilizes flat-ribbon cable connection technology, which significantly reduces assembly time and wiring errors when interfacing with sensor clusters or specialized distribution boards. Complying with EN 61131-2 Type 1/3 standards, this 24 VDC module is ideal for high-speed automated assembly lines, semiconductor manufacturing, and complex packaging machinery. By consolidating 16 discrete inputs into a single 12 mm housing, it maximizes control cabinet density while ensuring robust signal acquisition with a typical 0.2 ms input filter, protecting the system against industrial electrical noise and contact bounce.

Technical Configuration

The KL1872 hardware architecture is optimized for the K-bus internal communication protocol, transmitting the status of 16 digital inputs to the Bus Coupler as a single 16-bit process image. The signal acquisition follows the Type 3 characteristic, maintaining a typical input current of 3 mA to ensure reliable switching even with electronic sensors. A key technical feature is the 20-pin flat-ribbon cable interface, which provides a direct link to pre-assembled cable harnesses, eliminating the need for individual point-to-point wiring of 16 separate conductors. The module operates with a standard 24 VDC nominal voltage and provides 500 V electrical isolation between the K-bus and the field potential, safeguarding the central controller from field-side electrical surges.

Technical Specifications

Technical FAQs

Does the KL1872 require any software configuration?

No, the KL1872 is a "plug-and-play" module. It requires no address or configuration settings. The Bus Coupler automatically detects the 16-bit input width and maps it into the process image of the controller.

What is the advantage of the Type 3 input characteristic?

The Type 3 specification (EN 61131-2) defines a higher current draw at lower voltages compared to Type 1. This ensures better compatibility with 2-wire sensors and provides higher noise immunity in electrically "polluted" industrial environments.

How is power distributed to the sensors when using the ribbon cable?

The KL1872 is designed for signal acquisition. Typically, the 24 VDC supply for the sensors is distributed through the flat-ribbon cable harness or an external distribution board. The terminal itself does not utilize standard power contacts for field distribution.

Engineering & Installation Guide

• Flat-Ribbon Cable Integrity: When crimping the 20-pin connector, ensure the cable is perfectly perpendicular to the connector body. Misalignment can lead to "cross-talk" or intermittent signals between adjacent input bits. Use only high-quality flat cables rated for the industrial temperature range (up to 105 Celsius) to avoid insulation brittleness.

• Strain Relief: Since the ribbon cable is lighter than standard industrial wiring, it is susceptible to vibration fatigue. Secure the ribbon cable within 50 mm of the terminal using a cable tie or dedicated mounting bracket to prevent tension on the 20-pin header.

• Hazardous Area Compliance: The KL1872 carries ATEX and IECEx "Ex ec" (increased safety) markings. For installations in Zone 2 hazardous areas, the entire Bus Terminal assembly must be mounted in an IP54-rated enclosure, and the ribbon cable must be protected against mechanical damage to maintain the explosion protection rating.

• Input Filtering: The 0.2 ms filter is fixed. If your application involves high-speed pulses (e.g., from an encoder or flow meter) exceeding 2.5 kHz, ensure the pulse width is significantly greater than the 0.2 ms filter time to avoid missed counts.