Rockwell Automation Allen-Bradley 1756-EN2F User manual

User Manual Original Instructions
ControlLogix EtherNet/IP
Network Devices
Catalog Numbers 1756-EN2F, 1756-EN2FK, 1756-EN2T,
1756-EN2TK, 1756-EN2TP, 1756-EN2TPK, 1756-EN2TPXT,
1756-EN2TR, 1756-EN2TRK, 1756-EN2TXT, 1756-EN2TRXT,
1756-EN3TR, 1756-EN3TRK, 1756-EN4TR, 1756-EN4TRK,
1756-EN4TRXT, 1756-ENBT, 1756-ENBTK, 1756-EWEB

2Rockwell Automation Publication 1756-UM004D-EN-P - August 2022
ControlLogix EtherNet/IP Network Devices User Manual
Important User Information
Read this document and the documents listed in the additional resources section about installation, configuration, and
operation of this equipment before you install, configure, operate, or maintain this product. Users are required to familiarize
themselves with installation and wiring instructions in addition to requirements of all applicable codes, laws, and standards.
Activities including installation, adjustments, putting into service, use, assembly, disassembly, and maintenance are required to
be carried out by suitably trained personnel in accordance with applicable code of practice.
If this equipment is used in a manner not specified by the manufacturer, the protection provided by the equipment may be
impaired.
In no event will Rockwell Automation, Inc. be responsible or liable for indirect or consequential damages resulting from the use
or application of this equipment.
The examples and diagrams in this manual are included solely for illustrative purposes. Because of the many variables and
requirements associated with any particular installation, Rockwell Automation, Inc. cannot assume responsibility or liability for
actual use based on the examples and diagrams.
No patent liability is assumed by Rockwell Automation, Inc. with respect to use of information, circuits, equipment, or software
described in this manual.
Reproduction of the contents of this manual, in whole or in part, without written permission of Rockwell Automation, Inc., is
prohibited.
Throughout this manual, when necessary, we use notes to make you aware of safety considerations.
These labels may also be on or inside the equipment to provide specific precautions.
The following icon may appear in the text of this document.
WARNING: Identifies information about practices or circumstances that can cause an explosion in a hazardous environment,
which may lead to personal injury or death, property damage, or economic loss.
ATTENTION: Identifies information about practices or circumstances that can lead to personal injury or death, property
damage, or economic loss. Attentions help you identify a hazard, avoid a hazard, and recognize the consequence.
IMPORTANT Identifies information that is critical for successful application and understanding of the product.
SHOCK HAZARD: Labels may be on or inside the equipment, for example, a drive or motor, to alert people that dangerous
voltage may be present.
BURN HAZARD: Labels may be on or inside the equipment, for example, a drive or motor, to alert people that surfaces may
reach dangerous temperatures.
ARC FLASH HAZARD: Labels may be on or inside the equipment, for example, a motor control center, to alert people to
potential Arc Flash. Arc Flash will cause severe injury or death. Wear proper Personal Protective Equipment (PPE). Follow ALL
Regulatory requirements for safe work practices and for Personal Protective Equipment (PPE).
Identifies information that is useful and can help to make a process easier to do or easier to understand.

Rockwell Automation Publication 1756-UM004D-EN-P - August 2022 3
Table of Contents
Preface
About This Publication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Conventions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Download Firmware, AOP, EDS, and Other Files . . . . . . . . . . . . . . . . . . . . 5
Summary of Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Additional Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Chapter 1
ControlLogix EtherNet/IP
Network Device Overview
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
ControlLogix Network Device Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
EtherNet/IP Network Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
EtherNet/IP Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1756-EN4TR Device Properties Information. . . . . . . . . . . . . . . . . . . . . . . . 12
Simple Network Management Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Disable SNMP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Electronic Keying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Protected Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Enabling Explicit Protected Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Disabling Explicit Protected Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Protected Mode in a Redundant Adapter Pair . . . . . . . . . . . . . . . . . . . . . . 15
Enabling Explicit Protected Mode in a
Redundant Adapter Pair (RAP). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Disabling Explicit Protected Mode in a Redundant Adapter Pair . 15
How to Determine if the Module is in Explicit Protected Mode . . . 16
Secure Digital Card . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Disable Secure Digital Card. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
CIP Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Syslog Event Logging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Parallel Redundancy Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Device Level Ring (DLR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Chapter 2
Connect to the EtherNet/IP
Network
Set the IP Address. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Set the IP Address with Rotary Switches. . . . . . . . . . . . . . . . . . . . . . . . . . . 24
1756-EN4TR Mode Rotary Switch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Other Methods to Set the Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Reset the Module to Factory Default Value. . . . . . . . . . . . . . . . . . . . . . . . . 25
Redundant Adapter Considerations Setting the IP Address . . . . . . . . . 26
Chapter 3
Connect Redundant EtherNet/IP
Adapters
Redundant Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Redundant System Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

4Rockwell Automation Publication 1756-UM004D-EN-P - August 2022
Table of Contents
Redundant Switchovers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Switchover Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Status Display Codes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Configure a 1756-EN4TR Redundant Adapter Pair . . . . . . . . . . . . . . . . . . 30
Redundant Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Redundant Architecture Network Considerations. . . . . . . . . . . . . . . . . . 37
PRP Architecture with RedBox Switches. . . . . . . . . . . . . . . . . . . . . . . . . . . 39
PRP Architecture without RedBox Switches . . . . . . . . . . . . . . . . . . . . . . . 40
Chapter 4
Security Options MSG Instruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Configure the MSG Communication Path. . . . . . . . . . . . . . . . . . . . . . 41
Disable/Enable an Ethernet Port. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Disable/Enable an Ethernet Port with FactoryTalk Linx Network
Browser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Disable/Enable an Ethernet Port on the Port Configuration Tab. . 44
Disable an Ethernet Port with a MSG Instruction . . . . . . . . . . . . . . . 45
Disable the CIP Security Ports. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Disable the CIP Security Ports with FactoryTalk Linx Network
Browser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Disable the CIP Security Ports with a MSG Instruction . . . . . . . . . . 47
Disable/Enable LLDP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Disable the USB Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Disable/Enable the SD Card. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Disable/Enable the SD Card on the Module Properties Dialog. . . . 51
Disable/Enable the SD Card with a MSG Instruction . . . . . . . . . . . . 52
Disable/Enable the 4-character Status Display . . . . . . . . . . . . . . . . . . . . . 53
Disable/Enable All Categories of Messages . . . . . . . . . . . . . . . . . . . . . 53
Disable/Enable Individual Categories of Messages . . . . . . . . . . . . . . 54
Disable/Enable the 1756-EN4TR Webpages . . . . . . . . . . . . . . . . . . . . . . . . 56
Use a CIP Generic MSG to Disable the Webpages . . . . . . . . . . . . . . . 56
Use a CIP Generic MSG to Enable the Webpages. . . . . . . . . . . . . . . . 57
Disable/Enable Simple Network Management Protocol (SNMP) . . . . . 58
Use a CIP Generic MSG to Disable SNMP . . . . . . . . . . . . . . . . . . . . . . 58
Use a CIP Generic MSG to Enable SNMP. . . . . . . . . . . . . . . . . . . . . . . 59
Disable the Socket Object . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Disable the Email Object . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Appendix A
ControlLogix Network Device
Status Indicators
Status Indicators. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Single-Port Module Status Indicators. . . . . . . . . . . . . . . . . . . . . . . . . . 63
Dual-Port Module Status Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Diagnostic Web Pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Access the Diagnostic Web Pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Rockwell Automation Publication 1756-UM004D-EN-P - August 2022 5
Preface
About This Publication This manual describes how you can use ControlLogix® EtherNet/IP™
communication modules with a Logix 5000® controller and communicate with
various devices on the Ethernet/IP network.
Use this manual if you program applications that use EtherNet/IP networks
with ControlLogix controllers.
Conventions Be sure to understand these concepts and tools:
• FactoryTalk® Linx
• Studio 5000 Logix Designer® application
• ControlFLASH Plus™
• HMIs
• SNMP tools
Download Firmware, AOP,
EDS, and Other Files
Download firmware, associated files (such as Add-on Profiles, Electronic Data
Sheets, Device Type Manager), and access product release notes from the
Product Compatibility and Download Center at rok.auto/pcdc.
Summary of Changes This manual contains new and updated information. Changes throughout this
revision are marked by change bars, as shown to the right of this paragraph.
This manual was revised to add or update the information that is listed in this
table.
Topic Page
1756-EN4TR support for Parallel Redundancy Protocol Throughout
Specification updates for 1756-EN2F 9
Added 1756-EN4TR Device Properties Information 12
Update to Operation in Explicit Protected Mode 14
Update to CIP Security™ 19
Added section on Syslog Event Logging 20
Updates to 1756-EN4TR Mode Rotary Switch 25
Updates to Redundant Design Considerations 27
Updates to Redundant System Components 28
Updated PRP Architecture with RedBox Switches 39
Added PRP Architecture without RedBox Switches 40
Add new chapter on Security Options 41

6Rockwell Automation Publication 1756-UM004D-EN-P - August 2022
Additional Resources These documents contain additional information concerning related products
from Rockwell Automation.
You can view or download publications on Literature Library: rok.auto/
literature.
Resource Description
1756 EtherNet/IP Communication Modules Installation
Instructions, publication 1756-IN050
Provides information on how to install EtherNet/IP™
modules.
1756 ControlLogix Communication Modules Specifications,
publication 1756-TD003
Specifications for ControlLogix communication
modules.
ControlLogix 5570 Redundancy User Manual,
publication 1756-UM535
Provides information specific to ControlLogix 5570
redundancy systems.
ControlLogix 5580 Redundant Controller User Manual,
publication 1756-UM015
Provides information specific to ControlLogix 5580
redundancy systems.
Deploying Device Level Ring within a Converged Plantwide
Ethernet Architecture Design and Implementation Guide,
publication ENET-TD015
Highlights the key IACS application requirements,
technology, and supporting design considerations to
help with the successful design and deployment of
these specific use cases within the CPwE framework.
Ethernet Design Considerations Reference Manual,
publication ENET-RM002
Provides details about how to use EtherNet/IP
communication modules with Logix 5000 controllers
and communicate with other devices on the
EtherNet/IP network.
EtherNet/IP Device Level Ring Application Technique,
publication ENET-AT007
Describes DLR network operation, topologies,
configuration considerations, and diagnostic
methods.
EtherNet/IP Media Planning and Installation Manual
This manual is available from the Open DeviceNet® Vendor
Association (ODVA) at: http://www.odva.org.
Provides details about how to install, configure, and
maintain linear and Device Level Ring (DLR) networks
by using Rockwell Automation EtherNet/IP devices
that are equipped with embedded switch technology.
EtherNet/IP Network Devices User Manual,
publication ENET-UM006
Describes how to use EtherNet/IP communication
modules in Logix 5000 control systems.
EtherNet/IP Parallel Redundancy Protocol Application
Technique, publication ENET-AT006
Describes how you can configure a Parallel
Redundancy Protocol (PRP) network with a compatible
device or switch.
EtherNet/IP Socket Interface Application Technique,
publication ENET-AT002
Describes the socket interface that you can use to
program MSG instructions to communicate between a
Logix 5000 controller via an EtherNet/IP module and
Ethernet devices that do not support the EtherNet/IP
application protocol, such as barcode scanners, RFID
readers, or other standard Ethernet devices.
Industrial Automation Wiring and Grounding Guidelines,
publication 1770-4.1
Provides general guidelines for installing a Rockwell
Automation industrial system.
Product Certifications website, rok.auto/certifications.Provides declarations of conformity, certificates, and
other certification details.
Troubleshoot EtherNet/IP Networks Application
Technique, publication ENET-AT003
Provides details about how to assign IP addresses to
and how to troubleshoot EtherNet/IP networks and
devices.

Rockwell Automation Publication 1756-UM004D-EN-P - August 2022 7
Chapter 1
ControlLogix EtherNet/IP Network Device
Overview
Overview EtherNet/IP™ networks are communication networks that offer a
comprehensive suite of messages and services for many automation
applications.
This open network standard uses commonly available Ethernet
communication products to support real-time I/O messaging, information
exchange, and general messaging.
Topic Page
Overview 7
ControlLogix Network Device Features 8
EtherNet/IP Network Specifications 9
1756-EN4TR Device Properties Information 12
Simple Network Management Protocol 12
Electronic Keying 13
Protected Mode 14
Protected Mode in a Redundant Adapter Pair 15
Secure Digital Card 17
CIP Security 19
Parallel Redundancy Protocol 20
Device Level Ring (DLR) 21

8Rockwell Automation Publication 1756-UM004D-EN-P - August 2022
Chapter 1 ControlLogix EtherNet/IP Network Device Overview
ControlLogix Network
Device Features
The ControlLogix® EtherNet/IP network devices:
• Facilitate high-speed data transfer between Logix 5000® controllers and
remote I/O modules.
• Connect to multiple EtherNet/IP network topologies.
Figure 1 shows how Rockwell Automation EtherNet/IP communication
modules fit into a control system.
Figure 1 - EtherNet/IP Communication Modules in a Control System
STATUS
NET
LINK1
LINK2
5094-AENTR
EtherNet/IP
™
Adapter
FLEX5000
TM
I/O
PRP
DLR
POWER
X100
X10
X1
IP ADDRESS
STATUS
POWER
DIGITAL16INPUT 24 VDC
5094-IB16
11TB3
FLEX5000TM I/O
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
STATUS
POWER
DIGITAL16OUTPUT 24 VDC
5094-OB16
12TB3
FLEX5000TM I/O
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
STATUS
POWER
RELAY8OUTPUT ISOLATED
5094-OW8I
22TB3W
FLEX5000TM I/O
0 1 2 3 4 5 6 7
Switch
1756-EN4TR
1756 I/O Modules
1794-AENT
1794 I/O Modules
Workstation
ControlLogix 5580 Controller
1756 I/O Modules
1769-L27ERM
1769 I/O Modules
5069-AEN2TR
5069 I/O Modules
5069-L340ERM
5069 I/O Modules
1783-ETAP
PanelView™ Terminal
1783-ETAP
Workstation Stratix® 5400
5094-IB16
FLEX 5000™ I/O
1734-AENTR
1734 I/O Modules
1738-AENTR
1738 I/O Modules
PowerFlex®
Drive
Kinetix® 6500
Servo Drive
Star Topology
1769-L18ERM
1734 I/O Modules
DLR Topology
1756-EN4TR
ControlLogix Controller

Rockwell Automation Publication 1756-UM004D-EN-P - August 2022 9
Chapter 1 ControlLogix EtherNet/IP Network Device Overview
EtherNet/IP Network
Specifications
Table 1 - EtherNet/IP Communication Modules
Cat. No.(1) Description Media Communication Rate
Integrated Motion on
the EtherNet/IP
Network Axes, Max
1756-EN2F, 1756-EN2FK EtherNet/IP bridge, fiber Fiber 100 Mbps, no
auto-negotiation. 8
1756-EN2T
1756-EN2TK EtherNet/IP bridge, copper Copper 10/100 Mbps 8
1756-EN2TP, 1756-EN2TPK EtherNet/IP bridge, PRP support, copper Dual Copper 10/100 Mbps 8
1756-EN2TPXT ControlLogix-XT™, extended temperature
EtherNet/IP bridge, PRP support Dual Copper 10/100 Mbps 8
1756-EN2TR, 1756-EN2TRK EtherNet/IP bridge, embedded switch, copper Dual copper 10/100 Mbps 8
1756-EN2TXT ControlLogix-XT, extended temperature
EtherNet/IP bridge, copper, for extreme environments Copper 10/100 Mbps 8
1756-EN2TRXT ControlLogix-XT, extended temperature
EtherNet/IP bridge, embedded switch, copper Dual copper 10/100 Mbps 8
1756-EN3TR, 1756-EN3TRK EtherNet/IP bridge, embedded switch, copper Dual copper 10/100 Mbps 128
1756-EN4TR,
1756-EN4TRK EtherNet/IP bridge, embedded switch, copper Dual Copper 10/100 Mbps 1 Gbps 256
1756-EN4TRXT ControlLogix-XT, extended temperature
EtherNet/IP bridge, embedded switch, copper Dual Copper 10/100 Mbps 1 Gbps 256
1756-ENBT, 1756-ENBTK EtherNet/IP bridge, copper Copper 10/100 Mbps —
1756-EWEB Ethernet web server module Copper 10/100 Mbps —
(1) A catalog number ending in a K denotes a conformal coating.
Table 2 - ControlLogix EtherNet/IP Connections Specifications(1)
Cat. No. Connections CIP™ Unconnected Messages (backplane +
Ethernet)
TCP CIP(2)
1756-ENBT 64 128 64 + 64
1756-EN2F 128 256 128 + 128
1756-EN2T 128 256 128 + 128
1756-EN2TP 128 256 128 + 128
1756-EN2TR 128 256 128 + 128
1756-EN3TR 128 256 128 + 128
1756-EN4TR 512 1000 I/O,
528 messaging/HMI 256+256
1756-EWEB 64 128 128 + 128
(1) Includes the K conformal coating catalog numbers and the XT extreme environment catalog numbers.
(2) Except for the 1756-EN4TR, which has separate I/O and messaging/HMI CIP connections, these connections can be used for any combination of I/O and messaging/HMI.
Table 3 - ControlLogix EtherNet/IP Data Specifications(1)
Cat. No.
Produced/Consumed Tags
Socket Services Duplicate IP Detection
(starting revision)
Number of Multicast Tags,
Max(2) Unicast Available in RSLogix
5000® Software
1756-EN2F
32
Version 16.03.00 or later Yes
All Revisions
1756-EN2T Version 16.03.00 or later Yes
1756-EN2TP Version 24.00.00 or later Yes
1756-EN2TR Version 17.01.02 or later Yes
1756-EN3TR Version 18.02.00 or later Yes
1756-EN4TR Version 24.00.00 or later Yes
1756-ENBT Version 16.03.00 or later No Revision 3.3
1756-EWEB N/A Yes Revision 2.2
(1) Includes the K conformal coating catalog numbers and the XT extreme environment catalog numbers.
(2) Each controller can send a maximum of 32 multicast produced tags to one single consuming controller. If these same tags are sent to multiple consumers, the maximum number is 31.

10 Rockwell Automation Publication 1756-UM004D-EN-P - August 2022
Chapter 1 ControlLogix EtherNet/IP Network Device Overview
Table 4 - ControlLogix EtherNet/IP Specifications(1)
Cat. No. Firmware
Revision
RSLogix 5000
Software Version
RSLinx®
Software Version
Packet Rate Capacity (packets/
second)(2) Support for
Extended
Environment(3)
Integrated Motion on
the EtherNet/IP
Network Axes
I/O HMI/MSG
1756-ENBT Any 8.02.00 or later 2.30 or later 5000 900 No N/A
1756-EN2F
2.x 15.02.00 or later
2.51 or later
10,000
2000 No
N/A
3.6 or later 18.02.00 or later(4) 25,000(5) Up to 8 axes
supported(5)
1756-EN2T
2.x or earlier 15.02.00 or later
2.51 or later
10,000
2000 No
N/A
3.6 or later 18.02.00 or later(4) 25,000(5) Up to 8 axes
supported(5)
1756-EN2TXT
2.x 15.02.00 or later
2.51 or later
10,000
2000 Yes
N/A
3.6 or later 18.02.00 or later(4) 25,000(5) Up to 8 axes
supported(5)
1756-EN2TP Any 24.00.00 or later(4) 4.10 or later 25,000(5) 2000 No Up to 8 axes
supported(5)
1756-EN2TPXT 10.x or later 24.00.00 or later 4.10 or later 25,000(5) 2000 Yes Up to 8 axes
supported(5)
1756-EN2TR
2.x 17.01.02 or later 2.55 or later 10,000
2000 No
N/A
5.x or later 18.02.00 or later(4) 2.56 or later 25,000(5) Up to 8 axes
supported(5)
1756-EN2TRXT 5.028 or later 20.01.00 or later 2.56 or later 25,000(5) 2000 Yes Up to 8 axes
supported(5)
1756-EN3TR 3.6 or later 18.02.00 or later(4) 2.56 or later 25,000(5) 2000 No Up to 128 axes
supported(5)
1756-EN4TR Any 24.00.00 or later(6) 4.10 or later
• 50,000 without
CIP Security™
• 25,000 with
integrity
• 15,000 with
integrity and
confidentiality
• 3,700 without CIP
Security
•2,700with
integrity
•1,700with
integrity and
confidentiality
No Up to 256 axes
supported(5)
1756-EN4TRXT Any 24.00.00 or later(6) 4.10 or later
• 50,000 without
CIP Security
• 25,000 with
integrity
• 15,000 with
integrity and
confidentiality
• 3,700 without CIP
Security
•2,700with
integrity
•1,700with
integrity and
confidentiality
Yes Up to 256 axes
supported(5)
(1) Includes the K conformal coating catalog numbers.
(2) I/O numbers are maximums; they assume no HMI/MSG. HMI/MSG numbers are maximums, they assume no I/O. Packet rates vary depending on packet size. For more details, see
Troubleshoot EtherNet/IP Application Technique, publication ENET-AT003, and the EDS file for a specific catalog number.
(3) Module operates in a broad temperature spectrum, -20…+70 ºC (-4…+158 ºF), and meets ANSI/ISA-S71.04-1985 Class G1, G2 and G3, and cULus, Class 1 Div 2, C-Tick, CE, ATEX Zone 2 and SIL 2
requirements for increased protection against salts, corrosives, moisture/condensation, humidity, and fungal growth.
(4) This version is required to use CIP Sync™ technology, Integrated Motion on the EtherNet/IP Network, or Exact Match keying.
(5) This value assumes the use of a 1756-L8x or a 1756-L7x ControlLogix controller. For a 1756-L6x ControlLogix controller, see ControlLogix Controllers User Manual, publication 1756-UM001.
(6) CIP Security requires FactoryTalk® Linx version 6.11.00 or later.

Rockwell Automation Publication 1756-UM004D-EN-P - August 2022 11
Chapter 1 ControlLogix EtherNet/IP Network Device Overview
EtherNet/IP Network
The Ethernet Industrial (EtherNet/IP) network protocol is an open industrial-
networking standard that supports both real-time I/O messaging and message
exchange. The EtherNet/IP network uses off-the-shelf Ethernet
communication chips and physical media.
If you need to Select this interface
Control I/O modules and drives
Act as an adapter for I/O on remote EtherNet/IP links
Communicate with other EtherNet/IP devices (messages and HMI)
Bridge EtherNet/IP links to route messages to devices on other networks
1756-EN2F, 1756-EN2FK
1756-EN2T, 1756-EN2TK, 1756-EN2TXT
1756-EN2TP, 1756-EN2TPK, 1756-EN2TPXT
1756-EN2TR, 1756-EN2TRK, 1756-EN2TRXT
1756-EN4TR, 1756-EN4TRK, 1756-EN4TRXT
1756-ENBT, 1756-ENBTK
Support Device Level Ring (DLR) and linear topologies
1756-EN2TR, 1756-EN2TRK, 1756-EN2TRXT
1756-EN3TR, 1756-EN3TRK
1756-EN4TR, 1756-EN4TRK, 1756-EN4TRXT
Support for Parallel Redundancy Protocol 1756-EN2TP, 1756-EN2TPK, 1756-EN2TPXT
1756-EN4TR(1), 1756-EN4TRK(1), 1756-EN4TRXT(1)
Support for Redundant Adapters(2) 1756-EN4TR, 1756-EN4TRK, 1756-EN4TRXT
Provide control in environments where temperatures range from -25…+70 C (-13…+158 F)
1756-EN2TPXT
1756-EN2TRXT
1756-EN2TXT
1756-EN4TRXT
Secure access to a control system from within the plant network 1756-EN4TR, 1756-EN4TRK, 1756-EN4TRXT
Use an Internet browser to access tags remotely in a ControlLogix controller
Communicate with other EtherNet/IP or generic Ethernet devices (messaging only; no I/O control)
Bridge EtherNet/IP links to route messages to devices on other networks
1756-EWEB, 1756-EWEBK web server
(1) Starting with firmware revision 4.001.
(2) Redundant Adapters require version 3.001 and higher firmware. See the Product Compatibility and Download Center (PCDC) for that firmware.

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Chapter 1 ControlLogix EtherNet/IP Network Device Overview
1756-EN4TR Device
Properties Information
For 1756-EN4TR modules manufactured in July 2022 or later with firmware
revision 4.001 or later, you can use FactoryTalk Linx Network Browser to view:
• Catalog Number
• Manufacture Date
• Warranty Number
• Series
Simple Network
Management Protocol
SNMP enables the device to be remotely managed through other network
management software. SNMP defines the method of communication among
the devices and also denotes a manager for the monitoring and supervision of
the devices. For more information about SNMP, see the Ethernet Reference
Manual, publication ENET-RM002.
SNMP Passwords for these modules can be changed. For information on how
to change the SNMP Password, see the Knowledgebase Technote SNMP
Password and MIB Configuration.
Disable SNMP
To disable SNMP, see Disable/Enable Simple Network Management Protocol
(SNMP) on page 58.
Module Manufactured Before July 2022 with Firmware Revision 4.001 or earlier Module Manufactured in July 2022 or later with Firmware Revision 4.001 or later
Cat. No. Default Status Ability to Disable SNMP
1756-EN2F
On No
1756-EN2T
1756-EN2TP
1756-EN2TR
1756-EN3TR
1756-EN4TR Off Yes

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Chapter 1 ControlLogix EtherNet/IP Network Device Overview
Electronic Keying Electronic Keying reduces the possibility that you use the wrong device in a
control system. It compares the device that is defined in your project to the
installed device. If keying fails, a fault occurs. These attributes are compared in
the following table.
The following Electronic Keying options are available.
Carefully consider the implications of each keying option when selecting one.
For more detailed information on Electronic Keying, see Electronic Keying in
Logix 5000 Control Systems Application Technique, publication LOGIX-
AT001.
Attribute Description
Vendor The device manufacturer.
Device Type The general type of the product, for example, digital I/O module.
Product Code The specific type of the product. The Product Code maps to a catalog number.
Major Revision A number that represents the functional capabilities of a device.
Minor Revision A number that represents behavior changes in the device.
Keying Option Description
Compatible
Module
Lets the installed device accept the key of the device that is defined in the project when the
installed device can emulate the defined device. With Compatible Module, you can typically
replace a device with another device that has the following characteristics:
• Same catalog number
• Same or higher Major Revision
• Minor Revision as follows:
– If the Major Revision is the same, the Minor Revision must be the same or higher.
– If the Major Revision is higher, the Minor Revision can be any number.
Disable Keying
Indicates that the keying attributes are not considered when attempting to communicate with
a device. With Disable Keying, communication can occur with a device other than the type
specified in the project.
ATTENTION: Be cautious when using Disable Keying; if used incorrectly, this option can lead to
personal injury or death, property damage, or economic loss.
We strongly recommend that you do not use Disable Keying.
If you use Disable Keying, you must take full responsibility for understanding whether the
device being used can fulfill the functional requirements of the application.
Exact Match Indicates that all keying attributes must match to establish communication. If any attribute
does not match precisely, communication with the device does not occur.
IMPORTANT Changing Electronic Keying parameters online interrupts connections to
the device and any devices that are connected through the device.
Connections from other controllers can also be broken.
If an I/O connection to a device is interrupted, the result can be a loss of
data.

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Chapter 1 ControlLogix EtherNet/IP Network Device Overview
Protected Mode The 1756-EN2F, 1756-EN2T, 1756-EN2TP, 1756-EN2TR, 1756-EN3TR, and
1756-EN4TR support explicit protected mode.(1) When in this mode, the
module does not allow any configuration changes.
The only exception is for CIP Security devices such as the 1756-EN4TR. For
those, if a security policy has already been deployed to the module, then that
security policy can be modified while in explicit protected mode. If a security
policy has not yet been deployed to the module, then explicit protected mode w
prevents an initial policy from being deployed.
Enabling Explicit Protected Mode
To enable the module in an “explicit protected mode state”, follow these steps.
1. Set the rotary switches to position ‘900’.
2. Power up the device, and wait for the display to scroll, “Protected Mode –
Change Switch Settings”.
3. Power down the device.
4. Set the switches for normal operation.
5. Power up the device.
6. The device is now in Explicit Protected Mode.
Operation in Explicit Protected Mode
While operating in protected mode, the module rejects any CIP explicit
messages that would change the configuration of the module. For example,
you cannot change the IP address, speed, or duplex settings when the module
had Explicit Protected Mode enabled.
Disabling Explicit Protected Mode
To disable the “explicit protected mode state”, follow these steps.
1. Set the rotary switches on position ‘000’.
2. Power up the device, and wait for the display to scroll, “Unprotected
Mode – Change Switch Settings”.
3. Power down the device.
4. Set the switches for normal operation.
5. Power up the device.
6. The device is now in Unprotected Mode.
(1) For 1756-EN2F, 1756-EN2T, EN3TR, and 1756-EN2TR Versions 11.001 and later.
For 1756-EN2TP and 1756-EN4TR all versions
IMPORTANT When used in a Redundant Chassis Pair (RCP) with ControlLogix
controllers, the 1756-EN2x/1756-EN4x EtherNet/IP communication
modules have a special case for the Time Sync object, where the
PTP_Enable attribute is allowed to be set from the backplane.
This is needed to allow the controller to set the PTP enable using
unconnected messaging in the secondary (it is set via a class 1
connection in the primary controller, and in non-RCP cases).

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Chapter 1 ControlLogix EtherNet/IP Network Device Overview
Protected Mode in a
Redundant Adapter Pair
The 1756-EN4TR supports explicit protected mode in a redundant adapter pair.
In this mode, the module does not allow any configuration changes.
Enabling Explicit Protected Mode in a Redundant Adapter Pair (RAP)
To enable the module in an “explicit protected mode state in RAP”, follow these
steps.
1. Put your system in a qualified state.
2. Remove the secondary device from the chassis, put it in explicit mode
using the methods that are found on page 14, and insert the module back
into the chassis.
The system is qualified with the message “Explicit Protected Mode
Mismatch” on the module display.
3. Force a switchover either using AOP service or disconnect the cable.
4. Remove secondary (previous primary) device, put it in explicit mode and
insert module back.
The system has enabled explicit protected mode.
Disabling Explicit Protected Mode in a Redundant Adapter Pair
To disable the module in an “explicit protected mode state in RAP”, follow
these steps.
1. Put your system in a qualified state.
2. Remove the secondary device from the chassis, put it in non-protected
mode using the methods that are found on page 14, and insert the
module back into the chassis.
The system is qualified with the message “Explicit Protected Mode
Mismatch” on the module display.
3. Force a switchover either using AOP service or disconnect the cable.
4. Remove secondary (previous primary) device, put it in non-protected
mode and insert module back.
The system has disabled explicit protected mode.

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Chapter 1 ControlLogix EtherNet/IP Network Device Overview
How to Determine if the Module is in Explicit Protected Mode
To determine if your module is in explicit protected mode, either view the AOP
Module information page, or create a Generic CIP message. Set the following
parameters:
• Service Type: Get Single Attribute
•Class=1
• Instance = 1
• Attribute = 13(Hex)
The Destination Element Tag must be the INT type. Bit 3 is explicit protected
mode and a value of 1 indicates that protected mode is enabled.

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Chapter 1 ControlLogix EtherNet/IP Network Device Overview
Secure Digital Card The 1756-EN4TR uses a Secure Digital (SD) card to store:
• Module firmware
• Module configuration
• Fault logs
You can provide the fault logs to technical support rather than shipping
then entire module.
The SD card slot is inside the front panel of the module.
When the device is powered up, the device uses the configuration from the SD
card if the configuration does not exist in the device. When a blank SD card is
inserted, or powered up, the configuration is copied from the device to the SD
card that was inserted.
If the module powers up with a configuration that does not match the
configuration on the already inserted SD card, the configuration on the SD
card is used and copied to the module.
If the module is already powered, and an SD card is inserted, a warning
message is displayed.
IMPORTANT The 1756-EN4TR does not save the CIP Security configuration
information to the SD card. On power-up, the CIP Security setting
returns to the module default setting.
To see other potential error messages, see Table 19 on page 64.
SD Card inside front panel.

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Chapter 1 ControlLogix EtherNet/IP Network Device Overview
To change these results, do one of two things. One option is to do an out of box
reset on the module, if you want to use the configuration on the SD card. A
second option is to modify one of the configuration settings on the device, if
you want to use the configuration on the device.
The 1756-EN4TR supports the use of a 1784-SD1 (1 GB) and 1784-SD2 (2 GB)
card. You can use third-party SD cards with the device. You can use SD cards
with as much as 32 GB of memory.
If you use an SD card other than those cards that are available from
Rockwell Automation, unexpected results can occur. For example, you can
experience data corruption or data loss.
SD cards that are not provided by Rockwell Automation can have different
industrial, environmental, and certification ratings as those cards that are
available from Rockwell Automation. These cards can have difficulty with
survival in the same industrial environments as the industrially rated versions
available from Rockwell Automation.
Disable Secure Digital Card
To disable the SD card, see Disable/Enable the SD Card on page 51.
IMPORTANT If an SD card with a valid configuration is inserted into a 1756-EN4TR
module that does not match, an error is displayed on the status display
on the front of the module warning of this mis-configuration. If the SD
card is intended to be used in the 1756-EN4TR module it must be cleared
by external means and reinserted. If this is not done before the next
power cycle of the 1756-EN4TR with the non-matching configuration, this
configuration is copied to the 1756-EN4TR with all settings including the
IP address from the original module. This can possibly cause an IP
address conflict.
IMPORTANT Rockwell Automation does not test the use of third-party SD cards with
the device.

Rockwell Automation Publication 1756-UM004D-EN-P - August 2022 19
Chapter 1 ControlLogix EtherNet/IP Network Device Overview
CIP Security CIP Security™ is a standard, open communication mechanism that is defined
by the Open DeviceNet® Vendors’ Association (ODVA) that helps to provide a
secure data transport across an EtherNet/IP™ network. It lets CIP-connected
devices authenticate each other before transmitting and receiving data.
CIP Security uses the following security properties to help devices protect
themselves from malicious communication:
• Device Identity and Authentication
• Data Integrity and Authentication
• Data Confidentiality
Rockwell Automation uses the following products to implement CIP Security:
• FactoryTalk Services Platform, version 6.11 or later, with the following
components enabled:
- FactoryTalk Policy Manager
- FactoryTalk System Services
• FactoryTalk Linx, version 6.11 or later
• Studio 5000® Design Environment, version 31.00.00 or later
• CIP Security-enabled Rockwell Automation products, for example, the
product described in this publication
For more information on CIP Security, including which products support CIP
Security, see the CIP Security with Rockwell Automation Products Application
Technique, publication SECURE-AT001.
IMPORTANT Redundant Chassis Pair
1756-EN4TR modules with firmware revision 4.001 support CIP Security
when used in a redundant chassis pair with ControlLogix 5580
controllers that have firmware revision 34.011 or later. This supports
program upload/download/monitor/HMI (not I/O).
• The 1756-EN4TR pair must be configured for non-IP address swapping.
• The 1756-EN4TR pair cannot be configured for redundant adapter mode
while used in a redundant chassis pair with ControlLogix 5580
controllers.
• The 1756-EN4TR pair that is configured for CIP security cannot be used to
communicate with remote I/O, because I/O in ControlLogix redundancy
requires multi-cast. A second 1756-EN4TR pair is required for I/O.
Redundant Adapter Mode
CIP Security is not yet supported when the 1756-EN4TR is in redundant
adapter mode for remote I/O.
If a 1756-EN4TR is installed and using CIP Security, and it is reconfigured
to be part of a redundant adapter pair for remote I/O, the module loses
its CIP Security configuration. When this occurs, the I/O chassis will lose
communication with the controller. At this point, the CIP Security policy
must be redeployed.(1)
(1) CIP Security is not supported in redundant adapters. See Chapter 3 on page 27.

20 Rockwell Automation Publication 1756-UM004D-EN-P - August 2022
Chapter 1 ControlLogix EtherNet/IP Network Device Overview
Syslog Event Logging
The 1756-EN4TR module supports syslog event logging. Do not use FactoryTalk
AssetCentre for logging if you want to use a syslog collector.
Choose a syslog collector that supports the following:
• RFC-5424 syslog protocol
• Ability to receive messages from the 1756-EN4TR module
To set the IP address of the syslog collector, use FactoryTalk Policy Manager
software.
For more information, see:
• CIP Security with Rockwell Automation Products Application Technique,
publication SECURE-AT001.
• Logix 5000 Controller and I/O Fault Codes and Syslog Messages,
publication 1756-RD001.
Parallel Redundancy
Protocol
Parallel Redundancy Protocol (PRP) is defined in international standard
IEC 62439-3 and provides high-availability in Ethernet networks. PRP
technology creates seamless redundancy by sending duplicate frames to two
independent network infrastructures, which are known as LAN A and LAN B.
A PRP network includes the following components.
For more information about PRP, see the EtherNet/IP Parallel Redundancy
Protocol Application Technique, publication ENET-AT006.
IMPORTANT The 1756-EN4TR module must be connected to the same network as the
syslog collector.
Component Description
LAN A and LAN B Redundant, active Ethernet networks that operate in parallel.
Double attached node (DAN) An end device with PRP technology that connects to both LAN A and LAN B.
Single attached node (SAN) An end device without PRP technology that connects to either LAN A or LAN B.
A SAN does not have PRP redundancy.
Redundancy box (RedBox) A switch with PRP technology that connects devices without PRP technology to
both LAN A and LAN B.
Virtual double attached node
(VDAN)
An end device without PRP technology that connects to both LAN A and LAN B
through a RedBox.
A VDAN has PRP redundancy and appears to other nodes in the network as a DAN.
Infrastructure switch A switch that connects to either LAN A or LAN B and is not configured as a RedBox.