Allen‑Bradley 1756-CNB ControlNet Bridge Communication Module
The Allen‑Bradley 1756-CNB is a ControlNet bridge communication module built for the ControlLogix automation platform. It provides deterministic real-time communication links between ControlLogix controllers, remote I/O racks, drives and other ControlNet field devices via BNC coaxial interface, supporting scheduled I/O data exchange and unscheduled message transmission.
This single-slot module works independently or cooperates with Logix series CPUs to build distributed industrial control networks. It supports up to 64 bidirectional communication connections and integrates comprehensive network diagnostic functions, widely stocked as replacement spare parts for legacy production line system maintenance and retrofit projects.
Main Specifications
- Brand: Allen‑Bradley (Rockwell Automation)
- Model: 1756-CNB
- Product Type: ControlNet Bridge Communication Module
- Communication Protocol: ControlNet, CIP industrial protocol
- Physical Interface: Single BNC coaxial connector for RG6 cable
- Max Connection Quantity: 64 bidirectional network connections
- Backplane Power Consumption: 970mA @ 5.1VDC
- Operating Temperature Range: 0°C ~ +60°C
- Network Speed: 5 Mbps deterministic control communication
- Installation: Standard single-slot ControlLogix chassis mounting
Core Functions
- Establish deterministic real-time ControlNet communication for distributed ControlLogix control systems
- Transmit scheduled I/O data for remote racks, variable frequency drives and field automation equipment
- Support unscheduled messaging for program download, parameter setting and HMI data interaction
- Built-in network fault diagnosis, cable failure and node communication abnormality detection
- Enable cross-chassis data routing through ControlNet backbone network architecture
- Compatible with all standard 1756 series CPU, I/O modules and power supply hardware
- LED status indicators display network activity, fault status and module running state
- Support network address setting via dial switch for convenient on-site commissioning
- Industrial anti-interference design adapts to complex electromagnetic workshop environments
- Single-slot plug-in structure facilitates quick disassembly and emergency replacement maintenance
Application Scenarios
- Automobile manufacturing assembly line distributed control racks
- Petrochemical continuous process ControlLogix automation control systems
- Water treatment plant remote I/O and pump group centralized monitoring cabinets
- Food & beverage production line sequential control and motion control platforms
- Material handling, port crane and logistics equipment automation systems
- Pulp & paper factory continuous production line distributed control network
- Metallurgical workshop rolling equipment and furnace body control systems
- Oil & gas auxiliary equipment distributed monitoring and interlock control cabinets
- Renovation and spare parts support of legacy ControlLogix ControlNet network platforms
- Industrial communication module spare parts maintenance and emergency replacement projects
