The Allen-Bradley 1756-EN3TR is a communication bridge module that is part of the Allen-Bradley ControlLogix 2-port series of modules. Two 10-100 Mbps RJ-45 ports with embedded switches are included with this module. The controller supports up to 128 CIP motion axes (position loop) and up to 255 total axes, up to 128 TCP/IP connections and 256 Logix connections. Special features of the Allen-Bradley 1756-EN3TR include embedded switch technology, communication rates of 10-100 Mbps, 128 CIP motion axes, 128 TCP/IP connections, and 256 Logix connections. Its backplane current (mA) is 1A at 5.1V DC and 3mA at 24V DC. The maximum power consumption of the 1756-EN3TR is 5.1W and the power dissipation is 5.1W. It comes with a USB port. The 1756-EN3TR’s insulation voltage is 30 Volts continuous with an open enclosure and its operating temperature is 32-140o Fahrenheit. It has a current rating of 1.2 Amps, a thermal dissipation of 21.28 BTU per hour, and a power dissipation of 6.2 Watts. The power consumption is 5.1 Watts with a backplane current of 3 milliamps and 24 V DC and 1 amp at 5V DC. The 1756-EN3TR module supports EtherNet/IP connectivity and linear, star, and device-level ring (DLR) topologies. The module’s default configuration supports the linear and star topologies. The EtherNet/IP is an open industrial-networking standard protocol that supports real-time I/O message exchange. The EtherNet/IP network uses both off-the-shelf Ethernet communication chips and physical media for communication.

The 1756-EN3TR is an Ethernet Communication Module that is part of the ControlLogix Programmable Automation Controller (PAC) platform. This is an option module that is installed to any ControlLogix chassis whether it be a local or distributed I/O station. This module specifically functions as an Ethernet bridge module, connecting Ethernet capable processors, Remote I/O stations, Human Machine Interface (HMI), Supervisory Control and Data Acquisition (SCADA) system to a common network for implementing high-speed data exchange.

The 1756-EN3TR features supports Linear and Device Level Ring (DLR) topology, Linear is the minimum and simplest network connection wherein a single run of Cat5 or Cat6 physical media is used to implement Ethernet network. It does not offer a certain degree of redundancy while Device Level Ring (DLR) offers high-availability and redundancy.

The 1756-EN3TR features support up to 128 TCP connections, 256 Common Industrial Protocol (CIP) connections and 128 Backplane and 128 Ethernet CIP unconnected messages. These connections can be made through the integrated two (2) RJ45 Ethernet interfaces installed to the module. This module supports 10/100 Mbps transmission speed and covers a maximum distance of 100 meters which may be extended with the installation of an Ethernet switch or Fiber Media converter.

The 1756-EN3TR is backplane powered with a current consumption of 1 Ampere @ 5.1 Volts DC and 3 milliamperes @ 24 Volts DC with a power dissipation of 5.1 Watts and a thermal dissipation of 17.4 British Thermal Units (BTU) per hour.