DeviceNet to EtherNet/IP migration on Allen-Bradley systems: three options, program, network, power, checklist

Moving an Allen-Bradley system from DeviceNet to EtherNet/IP can be done in three ways: keep the DeviceNet trunk behind an EtherNet/IP-to-DeviceNet linking device, replace the devices one by one with their EtherNet/IP versions, or replace the whole network in one shutdown. Whichever way is chosen, the controller program changes: behind a linking device the scanner's arrays move to the linking device's tags, and each device moved to EtherNet/IP gets its own connection and its own tags. The network, the IP plan and the 24 V supply in the panel change with it.

Why plants move off DeviceNet

DeviceNet is CIP running on standard CAN. ODVA's overview gives up to 64 nodes, three data rates (125, 250 and 500 kbps) and a trunk line with drop lines, where signal and 24 V DC power run in the same cable. The trunk length depends on the data rate and the cable: on thick round cable, 500 m at 125 kbps and 100 m at 500 kbps; each drop is at most 6 m. EtherNet/IP uses the same CIP on standard, unmodified Ethernet with TCP/IP and UDP, in star, linear or Device Level Ring (DLR) topologies. A 1756-EN2TR runs at 10/100 Mbps.

The other reason to plan the move is the lifecycle of the parts already installed. Rockwell's product pages, read on 2 November 2026, show a mixed picture:

The ControlLogix scanner is still sold, so a ControlLogix plant is not forced off DeviceNet by the scanner. The pressure comes from the field devices and the smaller scanners: POINT I/O, FLEX I/O and ArmorPOINT adapters, network-powered ArmorBlock, and the E3 Plus. The 1734-ADN is End of Life with a discontinued date of 31 December 2026, and the 1794-ADN became Discontinued on 22 October 2026. Check each catalog number on the Rockwell page, or in the TDL end-of-life lookup, before ordering.

The three migration options

Keep DeviceNet behind a linking device

The 1788-EN2DNR connects a DeviceNet network of up to 63 nodes to EtherNet/IP. It has two RJ45 Ethernet ports with DLR support and also comes as the IP67 1788-EN2DNROM with M12 D-coded ports. The DeviceNet side runs at 125, 250 or 500 kbps. Its I/O tables hold at most 496 bytes of input and 492 bytes of output. The scanlist is still built and downloaded with RSNetWorx for DeviceNet; in Studio 5000 the linking device is added through its Add-on Profile, and the program sees its data as input and output arrays (the manual's example is EN2DNR:I.Data[0]). Rockwell's page for the 1769-SDN names the 1788-EN2DNR as its replacement.

This option suits a plant that has to replace the controller now, for example an SLC 500 or an older CompactLogix, and wants to keep the field devices for a later shutdown. Explicit messages can still reach DeviceNet devices: ODVA notes that a CIP message can pass between DeviceNet and EtherNet/IP without changes at the application layer, and the user only has to describe the path. What it does not solve is the lifecycle of the devices on the trunk, so plan it as a stage.

Replace device by device

Each family has its own path:

• PowerFlex 525 has embedded EtherNet/IP; the 25-COMM-E2P adds a dual-port EtherNet/IP adapter. A drive that talks through a 25-COMM-D can use its embedded port instead. Details and the command word differences are in PowerFlex 4/40 to PowerFlex 525.
• PowerFlex 755 has an embedded EtherNet/IP adapter; the 20-750-ENETR option module adds two ports for linear or DLR wiring. The option-card mapping for a move to 755TS is in PowerFlex 755 to 755TS. On PowerFlex Architecture Class drives that use a 20-COMM-D, its EtherNet/IP counterpart, the 20-COMM-E, is also Active Mature.
• E3 and E3 Plus overload relays were discontinued in October 2019; Rockwell's migration flyer points to E300 or E200. The E300 takes a 193-ECM-ETR EtherNet/IP communication module (Active) or a 193-ECM-DNT DeviceNet module. The flyer describes an E3 Plus emulation mode for the E300 on DeviceNet, which needs a Series B control module, so it helps a DeviceNet-first stage and not the move to EtherNet/IP.
• POINT I/O. The 1734-AENT and 1734-AENTR EtherNet/IP adapters belong to the same family as the 1734-ADN; the 1734-AENTR is Active. Before swapping an adapter on an existing rail, check backplane current and chassis size as described in Remote I/O on EtherNet/IP.
• FLEX I/O. Rockwell names the 5094-AENTR for the 1794-ADN, which means moving the rack to FLEX 5000 modules; see FLEX I/O 1794 to FLEX 5000.
• On-machine I/O. Both ArmorPOINT adapters, DeviceNet 1738-ADN12 and EtherNet/IP 1738-AENTR, are discontinued with no planned replacement. ArmorBlock EtherNet/IP is not a long-term answer either: the 1732E-IB16M12DR is End of Life with a discontinued date of 30 September 2028, and Rockwell names the ArmorBlock 5000 block 5032-CFGB16M12DR (Active) as its replacement. Check connectors and power for each block.

Device by device fits a plant that cannot stop a line for long. DeviceNet and EtherNet/IP devices then run side by side for a while: the remaining nodes stay on a DeviceNet scanner or behind a linking device, and the converted devices connect to the controller's EtherNet/IP port or module.

Replace the whole network in one shutdown

One shutdown replaces the scanner, the trunk and every device together. The I/O and drive work is larger, but there is no mixed period and no linking device left behind. TDL's Crown Da Nang body maker project followed this pattern: the DeviceNet I/O and drives were moved to EtherNet/IP with POINT I/O adapters, Stratix switches and PowerFlex 755 and 525 drives, the program was tested before the shutdown, and the machine was installed and started up during the line 1 shutdown. At the P&G Vietnam Dong An plant the packing machines were upgraded machine by machine, each one commissioned in turn, including the conversion of devices from DeviceNet to EtherNet/IP.

What changes in the program

The scanlist becomes the I/O tree. On DeviceNet, RSNetWorx for DeviceNet holds the scanlist and maps every node into the scanner's input and output memory, organised in DINTs. With Automap on Add, each node is placed in the next DINTs in sequence; with AutoScan the offset is calculated from the node address and the allocation size. The ladder logic then reads bits and words at fixed positions in those arrays. On EtherNet/IP, each device is added to the I/O configuration in Studio 5000 and gets its own connection. A drive Add-on Profile creates named tags for logic command and status, reference and feedback, and names each datalink after its drive parameter. Every old array reference therefore has to be mapped to a new tag. Build that table before touching the logic, one row per word or bit in use.

Scanner control logic goes away. A DeviceNet scanner must be idle for a scanlist download, which is done by putting the controller in Program mode or by clearing the scanner's CommandRegister.Run bit. Logic that sets this bit or reads scanner status has no meaning on EtherNet/IP. Device health now comes from each module's connection status; codes such as 16#0204 are explained in ControlLogix I/O fault 16#0204, 16#0203.

Explicit messages get new paths. MSG instructions that read or write device parameters through the DeviceNet scanner need a path through the EtherNet/IP module. On EtherNet/IP each message uses one connection, whatever the number of devices in its path, and Rockwell suggests reserving 10% of a module's packet rate for explicit messaging.

Configuration moves into the project. Rockwell's manual for PowerFlex 755T drives with built-in EtherNet/IP says that settings made in the drive Add-on Profile are saved in the controller project, and that Automatic Device Configuration (ADC) downloads them when a replaced drive or option module no longer matches. For PowerFlex 753/755 drives with the 20-750-ENETR, the option module manual lists ADC from RSLogix 5000 version 20 and drive firmware 4.001.

Connections and RPI are counted. Each EtherNet/IP connection has its own requested packet interval (RPI). Rack-optimized connections group digital modules on one connection; analog modules need direct connections. Rockwell's product pages give the 1756-EN2T and the 1756-EN2TR 256 CIP connections and 128 TCP connections each, so count devices and connections per module. If the controller still uses a 1756-ENBT, see 1756-ENBT end of life.

What changes in the network

A DeviceNet trunk needs a 121 Ω terminating resistor at each end, a 24 V supply sized for the devices, and a single ground point for V-, shield and drain. Rockwell's media guide has a checklist that covers the terminators, trunk and drop lengths, the common-mode voltage drop on V- and the 64-node limit, and before power-up it asks for a resistance check between CAN_H and CAN_L with power off, which should read about 50–60 Ω.

On EtherNet/IP these checks give way to a switch plan and an IP plan:

• Topology. Star through managed switches, linear through two-port devices, or a DLR ring. A DLR ring needs at least one device configured as ring supervisor; the function is disabled by default. Choosing between DLR and PRP is covered in DLR or PRP.
• IP addresses. Unless a DHCP server always gives each device the same address, Rockwell strongly recommends a fixed IP address and advises against dynamic assignment. On devices with rotary switches, valid settings are 001–254, and a setting of 002–254 also sets the gateway to 192.168.1.1 with a 255.255.255.0 mask, so decide early whether each machine stays on that default subnet.
• Multicast. Rockwell's EtherNet/IP network devices manual lists IGMP snooping (enabled by default) and querier (disabled by default) among the features of the devices it covers; check the setting on the switches actually used.
• Security. An Ethernet network that reaches the plant network needs zones and firewall rules; see PLC security on Rockwell systems and the ports in FactoryTalk and Logix firewall ports.

What changes in the panel

The DeviceNet cable carries 24 V DC power with the signal; ODVA gives up to 8 A on the trunk depending on cable type, and Rockwell's media guide keeps the voltage at each node between 11 and 25 V. Some devices take their power from that cable: network-powered 1732D ArmorBlock modules such as the 1732D-IB161212D, and Rockwell's E3 migration flyer notes that the E3 Plus drew 24 V DC from the DeviceNet trunk, while the E300 is supplied at 24 V DC, 120 V AC or 240 V AC.

EtherNet/IP does not carry that power, so every device that was fed from the trunk needs its own supply. Count the 24 V load again, add supplies and fuses where needed, and leave space for switches. A 1788-EN2DNR also needs 24 V DC: 150 mA for the module plus 60 mA for its DeviceNet interface. Where part of the trunk stays, its DeviceNet supply is still sized from the devices that remain, with about 10% added for surge as the media guide suggests.

A staged plan and checklist

1. Inventory. Go online with RSNetWorx for DeviceNet, upload the network and save a report. List every node: address, catalog number, series, firmware, I/O size and its place in the scanner map. Back up the controller program and the drive parameters.
2. Lifecycle. Look up every catalog number on Rockwell's page and note the status and the replacement it names.
3. Choose per area. For each machine, decide between linking device, device by device or full replacement, and write down which shutdown each stage needs.
4. Design. Draw the EtherNet/IP architecture, assign fixed IP addresses, choose switches and ring supervisors, and recalculate the 24 V supplies.
5. Program. Build the old-address to new-tag mapping table, add the Add-on Profiles, remove scanner control logic, re-path MSG instructions, and test offline with the real devices on a bench where possible.
6. Cut-over. Isolate the machine, install, set addresses before connecting, download, and check every connection status, DLR status and output before handing the machine back.
7. Hand-over. Update the electrical drawings and network diagram, and keep the final programs, the device configuration and the old RSNetWorx file as backups.

TDL's scope for this work is described on the DeviceNet and ControlNet to EtherNet/IP migration and industrial networks and OT security pages. For other legacy Allen-Bradley parts, see upgrade paths for legacy Allen-Bradley systems.