Description
Product Description
The Allen-Bradley 1756-CN2R/B is a high-performance, Series B ControlNet communication bridge module engineered for the ControlLogix platform. This module facilitates deterministic data exchange between controllers, remote I/O, drives, and other intelligent field devices. As a redundant bridge, it provides a robust communication backbone for critical control applications, ensuring high availability through dual-channel coaxial support.
Features
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Redundant Communication: Dual BNC ports allow for media redundancy, enabling the network to maintain operations seamlessly if one coaxial cable segment fails.
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Deterministic Throughput: Operates at a consistent 5 Mbps speed, ensuring predictable data delivery across the ControlNet network.
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High Capacity: Supports up to 99 nodes on the network with a maximum of 131 total connections, including 128 dedicated Logix connections.
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Integrated USB Port: Includes a local USB port for convenient configuration and diagnostics.
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Series B Reliability: Updated hardware revision for enhanced processing and improved stability in industrial environments.
Applications
This module is typically deployed in large-scale manufacturing and process control environments where network reliability is paramount. It is commonly used for distributed I/O control, inter-controller messaging, and high-speed data synchronization in ControlLogix systems.
Technical Specifications
| Model |
1756-CN2R/B |
| Series |
Series B |
| Communication Rate |
5 Mbps |
| USB Port Speed |
12 Mbps |
| Max Nodes |
99 |
| Max Connections |
131 (128 Logix) |
| Backplane Current (5.1V) |
1300 mA |
| Backplane Current (24V) |
3 mA |
| Max Power Dissipation |
6.7 Watts |
| Operating Temperature |
0 to 60 deg C |
| Enclosure Type |
Open |
Installation Guidelines
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Handling: This module is sensitive to electrostatic discharge (ESD). Ensure proper grounding procedures are followed before handling or installing the card.
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Mounting: Designed for installation in any standard 1756 ControlLogix chassis. Ensure the module is fully seated in the slot and the top/bottom retaining clips are secured.
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Cabling: Use only 1786-RG6 quad-shield coaxial cable for ControlNet connections to maintain signal integrity.
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Power: Always disconnect power from the ControlLogix chassis backplane before inserting or removing the communication module.
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Environment: Maintain adequate clearance around the chassis to ensure proper ventilation and cooling, keeping the ambient temperature within the specified 0 to 60 deg C range.
FAQ
Q: Does this module support non-redundant configurations?
A: While the 1756-CN2R/B is designed for redundant media applications, it can be used in non-redundant setups if only one BNC port is connected, though it is specifically built to provide the redundancy feature.
Q: Is this module compatible with all ControlLogix chassis?
A: It is compatible with standard 1756 series chassis, including the 1756-A4, A7, A10, A13, and A17 models.
