Allen Bradley 1756-EN2TP module Selection Guide for Dual-Port 100 Mbps ControlLogix PRP Networks
Allen Bradley 1756-EN2TP module is a chassis-based ControlLogix EtherNet/IP communication module designed for Parallel Redundancy Protocol (PRP) networks. Rockwell Automation describes catalog number 1756-EN2TP as a PRP dual-port, 10/100 Mbps twisted-pair module supporting up to 128 TCP connections. It is intended for industrial control architectures that require redundant Ethernet paths without relying on a single network route.
Quick identification
| Brand | Allen-Bradley / Rockwell Automation |
| Catalog number | 1756-EN2TP |
| Platform | ControlLogix 1756 chassis |
| Module type | EtherNet/IP communication module |
| Network redundancy | Parallel Redundancy Protocol (PRP) |
| Communication rate | 10/100 Mbps |
| TCP connections | Up to 128 |
| Maximum CIP connections | 256 |
| Chassis position | Any ControlLogix chassis slot |
The table is a catalog-selection reference. For a replacement or expansion project, verify the series letter, firmware revision, controller compatibility, network design, environmental rating, and certification requirements against the actual delivered module and current Rockwell Automation documentation.
Reference image notice: the supplied photograph shows Allen-Bradley 1734-AENT POINT I/O Ethernet adapter packaging. It is included only as a shared Allen-Bradley reference image and is not an exact photograph of Allen Bradley 1756-EN2TP module. The 1756-EN2TP product form, label, ports, and packaging are different. Confirm the catalog number on the actual nameplate before ordering.
What PRP support means for a ControlLogix system
The key selection point for Allen Bradley 1756-EN2TP module is PRP support. A PRP architecture uses two independent LAN paths so that duplicated frames can travel through both networks. This can help maintain communication if one network path fails, provided that the complete system topology, switches, end devices, configuration, and commissioning follow the applicable PRP design rules.
Do not select 1756-EN2TP only because another ControlLogix Ethernet module has two ports. Models such as 1756-EN2T, 1756-EN2TR, and 1756-EN4TR have different capability and topology profiles. The letters at the end of the catalog number are important: EN2TP identifies the PRP-oriented version, while nearby catalog numbers may be intended for other network designs.
Electrical and installation reference
- Current draw: 1 A at 5.1 V DC and 3 mA at 24 V DC.
- Power dissipation: 5.1 W; thermal dissipation: 17.4 BTU/h.
- Operating temperature reference: 0 to 60 °C.
- Relative humidity reference: 5 to 95%, noncondensing.
- Open-style module for installation in a suitable ControlLogix chassis and enclosure.
- Use Ethernet cabling, grounding, separation, and installation practices specified for the system.
These values support engineering review but do not replace the installation instructions. The chassis power budget, slot plan, enclosure environment, network addressing, managed infrastructure, and firmware strategy should be checked before installation.
1756-EN2TP versus the 1734-AENT reference image
The requested Allen Bradley 1756-EN2TP module and the pictured 1734-AENT are not interchangeable. 1756-EN2TP is a ControlLogix chassis communication module for EtherNet/IP PRP networking. 1734-AENT is a POINT I/O Ethernet network adapter used with the 1734 distributed I/O family. A photograph of 1734-AENT packaging cannot be used to verify the appearance, terminals, series, firmware, or condition of a 1756-EN2TP module.
Project and replacement checklist
- Copy the complete catalog number and series letter from the installed module label.
- Confirm that the intended topology is PRP rather than DLR, linear, or a single Ethernet network.
- Record the controller type, ControlLogix chassis, Studio 5000 environment, and required firmware revision.
- Review the number and type of I/O, produced/consumed tags, messages, HMIs, drives, and other connections.
- Check chassis power, available slot, operating environment, Ethernet media, and network infrastructure.
- For an existing redundant network, document LAN A and LAN B topology before removing the old module.
- Include quantity, destination, target delivery date, and required certificates in the RFQ.
For replacement work, Allen Bradley 1756-EN2TP module should be matched by full catalog number, series, and firmware requirements. A quote based only on the general description 'ControlLogix Ethernet module' may lead to the wrong topology or redundancy capability.
Frequently asked questions
What is 1756-EN2TP?
It is a ControlLogix EtherNet/IP communication module designed to support Parallel Redundancy Protocol networking with dual LAN connections.
What communication speed does it support?
Rockwell Automation lists a 10/100 Mbps communication rate over twisted-pair Ethernet media.
How many TCP connections are supported?
The official product description specifies up to 128 TCP connections.
Can the 1734-AENT in the photo replace 1756-EN2TP?
No. They belong to different hardware platforms and perform different system roles. The photo is a brand reference image only.
What should be provided for a quotation?
Send the full Allen Bradley 1756-EN2TP module catalog description, series and firmware details, quantity, application, chassis information, network topology, delivery destination, and a clear photo of the actual module label when available.
RFQ support for ControlLogix communication modules
HKXY can prepare a model-specific quotation for Allen Bradley 1756-EN2TP module and review related ControlLogix Ethernet communication modules as separate line items. Keeping the full catalog number, PRP requirement, series, and firmware information visible helps purchasing and engineering teams compare the correct configuration before an order is released.
