Allen-Bradley 1756-ENBT ControlLogix Ethernet/IP Communication Module

The Allen-Bradley 1756-ENBT, also cataloged as the 1756-ENBT Ethernet/IP communication bridge module, operates as a dedicated hardware component for Ethernet/IP packet routing and backplane data exchange within ControlLogix communication networks.

Configured for Ethernet/IP network bridging in ControlLogix chassis systems, the Allen-Bradley 1756-ENBT (1756-ENBT communication module) provides direct physical and protocol-level execution of 10/100 Mbps industrial Ethernet frame handling, enabling TCP/IP connection management and Logix tag exchange across distributed controllers and remote I/O devices.

Suffix Breakdown & Model Matrix

No suffix segmentation is defined for 1756-ENBT. The identifier represents a fixed ControlLogix Ethernet/IP bridge module within the ControlLogix product family.

Hardware Specifications

Backplane Bus Communication Velocity & EtherNet/IP Deterministic Network Handling

Within ControlLogix chassis architectures, the 1756-ENBT executes Ethernet/IP frame scheduling through backplane-synchronized communication cycles. The module maps Logix tags into cyclic TCP/IP connection structures while maintaining deterministic update alignment with controller scan tasks. Connection handling is constrained by backplane current availability (700 mA at 5.1 VDC), where network throughput and tag propagation are coordinated through chassis-level arbitration. Multicast tag handling (up to 32 tags) is processed via internal buffering before Ethernet transmission over copper media.

Frequently Asked Questions (FAQ)

Q: Can the 1756-ENBT support simultaneous Ethernet/IP and TCP socket services?
A: Yes. The module supports socket services alongside Ethernet/IP communication within its defined connection limits.

Q: What is the effect of backplane current draw on network performance?
A: The module draws 700 mA at 5.1 VDC. This affects chassis power budget but does not directly limit Ethernet port bandwidth.

Q: Is hot-swap insertion supported for the 1756-ENBT module?
A: Hot-swap is not defined in the provided specifications. Standard practice requires chassis power-down before installation.

Field Installation Guidelines

The module must be installed into a compatible ControlLogix 1756 chassis with correct slot alignment to ensure backplane connector integrity. Ethernet cabling should use shielded copper media with proper grounding at the cabinet entry point. Signal routing must be separated from high-voltage conductors to reduce electromagnetic coupling into the RJ45 interface. Backplane connector seating must be verified to avoid intermittent contact faults during scan cycles. Installation should follow standard ESD handling procedures for communication modules.