Overview
The Allen-Bradley 1756-ENBT is an EtherNet/IP communication bridge module designed for ControlLogix chassis-based automation systems. This single-port module enables seamless Ethernet connectivity at 10/100 Mbps, allowing controllers to communicate with distributed I/O, drives, HMIs, and other EtherNet/IP devices across facility networks. The module occupies one slot in a standard ControlLogix chassis and supports up to 128 CIP connections for flexible I/O and messaging configurations.
Key Features
- Single RJ45 EtherNet/IP Port: One Ethernet RJ45 Category 5 port with auto-negotiating 10/100 Mbps capability
- 128 CIP Connections: 128 CIP connections for EtherNet/IP communication, supporting real-time I/O, HMI messages, and unconnected messaging
- TCP/IP Connectivity: Supports up to 64 TCP connections for robust network integration
- Multicast Support: Up to 32 multicast tags for efficient broadcast messaging to multiple controllers
- Status Monitoring: Includes status indicators as well as a module status display for real-time operational visibility
- Socket Services & SNMP: Supports real-time I/O messaging, information exchange, and general messaging; meets the common industry protocol (CIP) for safety in data transmission
Technical Specifications
- Communication Speed: 10 or 100 Mbps copper media
- Backplane Current Draw: 700 milliamps at 5.1 Volts DC; 3 milliamps at 24 Volts DC
- Power Dissipation: 3.7 Watts
- Thermal Dissipation: 12.6 BTU per hour
- Isolation Voltage: 30 Volts from Ethernet network to backplane
- Chassis Slot Width: 1 slot
- Operating Temperature Range: 0–60 degrees Celsius
- Weight: 0.22 lbs
Typical Applications
The 1756-ENBT is widely used in ControlLogix-based automation systems for:
- Factory automation and discrete manufacturing control
- Drive communication and motion control system integration
- Remote I/O node bridging across Ethernet networks
- HMI-to-controller real-time data exchange
- SCADA and supervisory systems over industrial Ethernet
- Multi-site consolidation and plant-wide network integration
Compatibility & Replacements
Compatible With
- ControlLogix 1756 chassis (5500, 5550, 5560, 5570, 5580, 5590)
- CompactLogix via remote adapter modules
- Studio 5000 Logix Designer (RSLogix 5000 v16.03.00 or later)
- EtherNet/IP networks and bridges (SCADA, HMI platforms)
- Industrial Ethernet switches and managed networks
- Drives and I/O modules supporting CIP protocol
Replaces / Drop-In Replacement For
- Functionally replaced by 1756-EN2T (newer, higher-performance version)
- Earlier ControlLogix Ethernet communication cards in legacy systems
- Note: Discontinued by manufacturer; verify compatibility with your system integrator before ordering
Works With
- Studio 5000 Logix Designer (RSLogix 5000) software platform
- EtherNet/IP protocol and CIP messaging
- SNMP network management and monitoring
- Real-time I/O and HMI messaging at up to 500 pps I/O, 900 pps HMI/MSG packet rates
- Socket services for custom messaging applications
