1756-CN2RB

Overview of Allen-Bradley 1756-CN2RB ControlLogix ControlNet Redundant Bridge Module

The Allen-Bradley 1756-CN2RB is a ControlLogix communication module designed to provide redundant connectivity between two ControlNet networks. It features dual BNC ControlNet ports with 5 Mbps transmission speed and one USB port for local programming. Designed for use in ControlNet redundant topologies, it ensures uninterrupted network communication by switching automatically between redundant paths.

Key Features of 1756-CN2RB

• Dual ControlNet BNC ports for redundant network connectivity.
• Supports 5 Mbps ControlNet communication over up to 99 nodes.
• One USB 1.1 port for local programming (not for network communication).
• Supports up to 128 Logix connections and 131 communication connections total.
• Compatible with ControlLogix chassis including 1756-A4, A7, A10, A13, and A17 models.
• Power supply compatibility with standard and redundant 1756 series power supplies.
• Single slot module open enclosure type with operating temperature range 0 to 60°C (32 to 140°F).
• Supports multipath network topology with automatic failover for reliability.
• Uses 1786-RG6 quad-shielded coaxial cable for ControlNet network connections.
• Power dissipation typically 6.7 Watts (22.9 BTU/hr).

Technical Specifications

Applications / Use Cases

The 1756-CN2RB module provides fault-tolerant communication between ControlNet networks ideal for mission-critical industrial automation systems. It ensures high availability and data integrity in distributed control systems found in manufacturing, process control, and infrastructure applications.