Configured for high-speed network communication and control data routing in ControlLogix platforms, the Allen-Bradley 1756-CN2RXT (1756-CN2RXT Interface Module) provides direct physical and electrical execution across redundant media architectures.

Model Identification & Part Structure

• Base Catalog Number: 1756-CN2RXT
• Hardware Series: ControlLogix Network Communication Interface
• Module Classification: Redundant Coaxial Media ControlNet Module
• Revision Identifier: Extended Temperature Range Compliant

Hardware Specifications

Industrial Control & Network Determinism

As part of the Allen-Bradley ControlLogix and PLC platform ecosystem, this hardware facilitates Profinet and EtherNet/IP deterministic networks alongside ControlNet backplane bus communication velocity licenses. The unit processes up to 128 connections over dual BNC physical connectors, utilizing a 5 Mbps data rate to maintain synchronized data exchange across distributed nodes. The embedded firmware flash compatibility ensures seamless integration into existing rack configurations while maintaining firm backplane bus communication velocity limits.

Ordering Info

• 1 x Allen-Bradley 1756-CN2RXT Interface Module
• 1 x Protective Dust Cover Set for BNC Ports
• 1 x Grounding Terminal Hardware Kit

Field Installation Guidelines

• Chassis Slot Placement: Insert the module into any available slot within a standard ControlLogix 1756 chassis. Avoid placing the unit adjacent to high-voltage power entry modules to minimize electromagnetic interference.
• Coaxial Cable Termination: Connect 75-ohm RG-6 coaxial cables to the dual BNC connectors. Ensure proper grounding of the cable shield at both ends or per facility earthing standards to prevent ground loop currents.
• USB Access Point Utilization: Access the front-panel USB port strictly for temporary configuration, programming, and firmware updates using certified industrial programming cables.

Frequently Asked Questions

• Question: Does the 1756-CN2RXT module support live insertion and removal under power (RIUP)?
• Answer: Yes, the module is engineered for RIUP, allowing operators to insert or remove it from a powered ControlLogix chassis without disrupting the entire rack operation.
• Question: What is the maximum operating temperature supported by this extended environment variant?
• Answer: The module is rated for deployment in harsh industrial environments ranging from -25 to +70 deg C.
• Question: How does the module handle media redundancy on the ControlNet network?
• Answer: It utilizes dual coaxial BNC connectors to route data simultaneously across primary and secondary media channels, ensuring automatic switchover upon cable failure.
• Question: What is the backplane current draw required by this interface module?
• Answer: The unit draws 1.3 Amperes at 5.1 Volts DC from the ControlLogix chassis power supply backplane.
• Question: Can standard commercial coaxial cables be used for network connections?
• Answer: No, installations require high-grade 75-ohm coaxial cable matched to ControlNet specifications to maintain signal integrity at 5 Mbps.
• Question: Is external power required in addition to the chassis backplane supply?
• Answer: No external power source is needed; all operational power is derived internally from the 1756 chassis backplane.
• Question: What is the total connection capacity handled by the network interface?
• Answer: The hardware supports a maximum of 128 configured connections for routing I/O and controller-to-controller messaging.
• Question: How should the module be handled during firmware flash updates?
• Answer: Ensure a stable backplane power supply and uninterrupted USB connection during execution to prevent communication dropouts and corruption.