Allen-Bradley 1756-EN2TR Overview
The Allen-Bradley 1756-EN2TR is a ControlLogix EtherNet/IP bridge module that enables robust network communication for industrial automation. This dual-port module supports 10/100 Mbps speeds and is designed for redundant Ethernet networks. Engineers value its ability to handle up to 128 TCP/IP connections and 256 CIP connections, making it a versatile choice for modern control systems.
This module fits into any slot of a ControlLogix chassis and draws just 1 amp from the 5V backplane supply. With a power dissipation of 5.1 watts, it operates efficiently within a temperature range of 0 to 60 degrees Celsius. The 1756-EN2TR also includes a USB 1.1 port for local configuration, which simplifies initial setup and maintenance tasks.
Key Technical Specifications
The 1756-EN2TR offers several specifications that matter for system design. It supports both ring and linear topologies, which gives flexibility when planning network architecture. The module also supports up to 8 axes of integrated motion, making it suitable for applications requiring coordinated motion control over EtherNet/IP.
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Communication Rate: 10/100 Mbps Ethernet/IP
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Ports: Two RJ45, one USB 1.1
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Backplane Current: 1 A at 5V, 3 mA at 24V
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Power Consumption: 5.1 Watts
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Operating Temperature: 0 to 60°C
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Connections: 128 TCP/IP, 256 CIP
These specifications allow the module to handle demanding communication tasks without excessive power use. The dual RJ45 ports enable redundant network configurations, which improve system availability and fault tolerance.
Network Redundancy and Topology Support
One of the standout features of the 1756-EN2TR is its support for redundant Ethernet networks. The dual-port design allows engineers to implement Device Level Ring (DLR) or Parallel Redundancy Protocol (PRP) networks. This capability is critical for applications where downtime is unacceptable, such as continuous process control or high-speed packaging lines.
The module also supports star topology with qualified partner devices, including Flex I/O, POINT I/O, CompactLogix, and other ControlLogix controllers. This versatility makes it easier to integrate into existing plant networks without major redesigns.
Configuration and Setup Best Practices
To configure the 1756-EN2TR, engineers can use the BOOTP-DHCP tool from Allen-Bradley to assign IP addresses. This tool works with a wide range of Ethernet devices, simplifying network management. After setting the IP address, you can use standard software like RSLogix 5000 or Studio 5000 to configure the module's parameters.
For wiring, the module uses unshielded RJ45 connectors with Category 5 or 6 twisted-pair cables. These cables are readily available and easy to fabricate, reducing installation costs. Ensure that all network parameters, such as subnet masks and gateways, are correctly defined to avoid communication issues.
Applications and Compatibility
The 1756-EN2TR is compatible with a broad range of Allen-Bradley controllers, including SLC 500, PLC-5, and MicroLogix. It also communicates with HMI and SCADA systems, both from Allen-Bradley and third-party vendors. This compatibility makes it a practical choice for system integrators who need to connect diverse equipment.
With support for up to 8 axes of motion, the module is well-suited for applications like CNC machines, robotic cells, and material handling systems. Its ability to handle simultaneous safety and control data also meets CIP safety standards, enhancing overall system safety.
Conclusion
The Allen-Bradley 1756-EN2TR is a reliable and feature-rich communication module for ControlLogix platforms. Its dual-port design, high connection capacity, and broad compatibility make it an excellent choice for engineers seeking to build efficient and redundant EtherNet/IP networks. By understanding its specifications and setup requirements, you can maximize the performance and uptime of your automation systems.