The Allen-Bradley 1756-CNB/E is a ControlLogix ControlNet communication bridge module designed to facilitate high-speed data exchange between ControlLogix controllers and other devices on a ControlNet network. This module acts as a bridge, allowing for efficient communication and control across distributed I/O, peer-to-peer messaging, and controller-to-controller data transfer.
Features
Supports up to 99 nodes on a single ControlNet network.
Provides up to 64 communication connections.
Standard ControlNet communication rate of 5 Mbps.
Designed for seamless integration within the ControlLogix chassis environment.
Optimized for deterministic, high-speed industrial communication.
Technical Specifications
Product Model
1756-CNB/E
Series
ControlLogix
Module Type
ControlNet Bridge Module
Communication Rate
5 Mbps
Max Nodes
99
Max Connections
64
Input Current (5.1V DC)
970 mA
Input Current (24V DC)
1.7 mA
Thermal Dissipation
17.4 BTU/hr
Installation Guidelines
Ensure the ControlLogix chassis is powered down before inserting or removing the module to prevent electrical damage.
Slide the module into the designated chassis slot and secure it using the top and bottom latches.
Ensure proper grounding of the ControlLogix chassis to a common ground point to minimize EMI interference.
Use shielded ControlNet cabling and appropriate tap connectors to maintain network integrity.
Verify that the module is firmly seated and the backplane connector is fully engaged.
FAQ
What is the primary function of the 1756-CNB/E?
The 1756-CNB/E serves as a communication bridge that allows ControlLogix controllers to communicate over the ControlNet network, supporting I/O control and messaging.
Can this module be hot-swapped?
Yes, the ControlLogix system supports Removal and Insertion Under Power (RIUP), allowing you to replace the module without powering down the entire chassis, provided the environment is not hazardous.
What is the communication speed of this module?
The module operates at a fixed ControlNet communication rate of 5 megabits per second.
