Product Overview

The Allen-Bradley 1768-ENBT is a high-performance EtherNet/IP communication interface designed specifically for the 1768 CompactLogix™ controller platform. This module functions as a sophisticated bridge between the high-speed 1768 backplane and an Ethernet network, allowing controllers like the L43 and L45 to engage in real-time I/O control, messaging, and data acquisition. By implementing the Common Industrial Protocol (CIP™) over standard TCP/IP, the 1768-ENBT facilitates seamless vertical integration from the plant floor to enterprise-level SCADA and HMI systems.

This module is essential for modern industrial environments that require distributed control and remote monitoring. It eliminates the need for proprietary network hardware by utilizing standard CAT5 or CAT6 cabling and off-the-shelf industrial switches, significantly reducing infrastructure costs while maintaining the deterministic performance required for automated machinery.

Network Capacity and Connectivity

The 1768-ENBT is engineered to manage high-volume data traffic with robust session handling capabilities.

• Session Management: Supports up to 32 simultaneous TCP/IP sessions and 64 logical CIP connections, providing ample headroom for complex multi-device networks.

• Auto-Sensing Technology: The integrated RJ45 port automatically detects network speeds of 10 Mbps or 100 Mbps and adjusts for full or half-duplex operation.

• Controller Scalability: Designed for multi-module configurations; a 1768-L43 system can host up to two modules, while the 1768-L45 can support up to four, enabling physical network segmentation for security or performance optimization.

• Protocol Support: Fully compatible with EtherNet/IP for I/O messaging, explicit messaging (client/server), and web-based diagnostics.

Technical Specifications

• Manufacturer: Allen-Bradley (Rockwell Automation)

• Model Number: 1768-ENBT

• Module Type: Communication Bridge / Network Adapter

• Communication Rate: 10/100 Mbps (Auto-negotiated)

• Cabling Requirements: Category 5 or 6 Unshielded Twisted Pair (UTP)

• Backplane Current: 814mA @ 5.1V DC

• Power Dissipation: 4.15 Watts

• Operating Temperature: 0°C to 60°C (32°F to 140°F)

• Dimensions: 13.0 x 14.5 x 3.5 cm

• Weight: 0.9 kg (1.98 lbs)

Diagnostic and Safety Features

The module includes integrated hardware and software tools to ensure continuous network uptime.

• Visual Status Indicators: Front-facing LEDs provide real-time feedback on Module Health, Network Activity, and Link Status, allowing for rapid floor-level troubleshooting.

• Built-in Web Server: Includes an internal web page for viewing module information, network statistics, and diagnostic counters without requiring specialized software.

• Electrostatic Protection: Manufactured with high-tolerance circuitry that requires standard ESD handling procedures during installation to maintain long-term component integrity.

• Bridge Functionality: Acts as a gateway, allowing users to "browse" through the 1768-ENBT to other modules on the backplane or separate networks linked to the controller.