CX5120-N031 BECKHOFF Intel Atom Embedded PC with Terminated RS485 Interface

Product Overview

The CX5120-N031 (CX5120N031) is a high-performance, fanless Embedded PC designed for DIN rail mounting, powered by an efficient Intel Atom® multi-core processor. This specific configuration is equipped with a factory-integrated RS485 interface via a 9-pin D-sub socket, specifically configured for use as an end point. In industrial B2B sectors such as building automation, renewable energy monitoring, and long-distance serial networking, the CX5120-N031 serves as a robust intelligent controller. It excels in bridging high-speed EtherCAT I/O with legacy serial bus systems, providing the computational overhead required for TwinCAT 3 PLC and Motion Control tasks while maintaining a rugged, maintenance-free hardware profile.

Technical Configuration (Deep Dive)

The CX5120-N031 is technically optimized for RS485 bus integrity. Unlike the -0002 variant, this "N031" model is pre-configured as an end point with termination on. This means the internal 120-ohm termination resistor is active, and the module is set to without echo (half-duplex). This configuration is critical for preventing signal reflections in serial RS485 networks, ensuring high-speed data reliability over long cable runs without the need for external resistors.

The unit leverages the advanced Intel Atom® architecture to deliver a superior performance-to-watt ratio. It supports automatic recognition of both E-bus (EtherCAT) and K-bus (Bus Terminals), allowing it to function as a universal head-station for any Beckhoff I/O segment. The fanless design ensures longevity in dusty or vibration-prone environments where active cooling would fail.

Technical Specifications

Technical FAQs

What does "Termination ON" mean for my network design?

The CX5120-N031 has an internal 120-ohm resistor engaged across the RS485 data lines. This module must be placed at the physical beginning or the physical end of your RS485 daisy-chain to ensure impedance matching and prevent signal distortion.

Can I use this for Modbus RTU communication?

Absolutely. The RS485 interface is fully compatible with the Modbus RTU protocol. In TwinCAT, you can simply map the serial port to the Modbus RTU master or slave library to communicate with drives, meters, or third-party sensors.

Does this model support TwinCAT 3 Platform Level 40?

Yes. The CX5120 series typically operates at the Performance (40) platform level, providing ample power for multi-tasking PLC environments and complex communication handling.

Engineering & Installation Guide

• Network Topology: Because this unit is configured with internal termination, avoid placing it in the middle of an RS485 bus. Doing so would load the bus incorrectly and likely cause communication errors. Always use shielded, twisted-pair cable for the D-sub connection.

• Thermal Clearances: For fanless operation up to 60 Celsius, the unit must be mounted horizontally. Ensure a minimum of 30 mm of free space above and below the cooling fins to allow for natural heat dissipation.

• Bus Integration: The CX5120 detects the connected I/O bus type during the boot phase. When switching from E-bus to K-bus terminals, ensure a complete power cycle of the system to allow the automatic bus recognition logic to reset.

Engineering Advantages

The CX5120-N031 represents a professional-grade solution for "Legacy-to-Industry 4.0" integration. By integrating a hardware-terminated RS485 port directly into a powerful Intel Atom® PC, it reduces the need for external gateways and specialized wiring. Its durability is proven by its compliance with EN 60068-2-6/27 for vibration and shock resistance, ensuring it remains operational in the most demanding industrial settings. The combination of high-speed local I/O expansion and ready-to-use serial networking makes it one of the most flexible Embedded PCs in the Beckhoff portfolio.