CompactLogix 1768-L43 and 1768-L45 end of life: migrating to 5380 (5069) or 5370 (1769-L3x)

CompactLogix 1768-L43 and 1768-L45 controllers were discontinued on 30 June 2020. The modules that sit on the 1768 chassis with them (1768-ENBT, 1768-EWEB, 1768-CNB, 1768-CNBR, 1768-M04SE and the 1768-PA3/PB3 power supplies) were also discontinued during 2020. Rockwell's product pages (read 27 October 2026) list all of them as "Engineering Replacement" with no replacement catalog number, which means the system has to be re-engineered rather than swapped part for part. There are two targets: CompactLogix 5370 L3 (1769-L3xER), which keeps the 1769 I/O as local I/O, or CompactLogix 5380 (5069-L3xxER), which keeps the 1769 I/O only as a remote rack through a 1769-AENTR, or replaces it with Compact 5000 I/O.

This article covers 1768 systems only. For 1769-L31, L32E and L35E, and for the general choice between 5370 and 5380, see CompactLogix 1769-L31/L32E/L35E end of life.

Lifecycle of the 1768 catalog numbers

All nine are listed as "Engineering Replacement" with no replacement catalog number. Memory sizes are from 1769-TD005O (p. 38). Rockwell published a migration profile for this family, MIGRAT-PP037A (11/2018): it announced the planned discontinuation of 1768-L4x controllers in 2020 and points to CompactLogix 5380 (pp. 1–2).

A 1768 system has two parts: the 1768 chassis on the left (1768 power supply, 1768 modules, controller at the far right) and 1769 I/O modules to the right of the controller (1768-UM001F pp. 73–75). The whole 1768 chassis goes in a migration. The decision is whether the 1769 I/O stays or goes.

Replacements named by Rockwell

The replacement table in selection guide 1769-SG003A (p. 14) groups 1768-L43 and 1768-L45 with 1769-L33ER or 1769-L33ERM as replacements; 1769-L36ERM is listed as a replacement for any earlier L3x/L4x controller. The differences Rockwell lists: more memory, Integrated Motion on EtherNet/IP (catalog numbers with M), a USB port instead of the RS-232 port, dual-port EtherNet/IP, and an SD card instead of a CompactFlash card. A footnote on the same page warns that a system with more expansion modules than the new controller accepts needs a larger controller.

Data: 1769-TD005O pp. 38–39; 1768-UM001F p. 107; 1769-SG003A pp. 9, 14, 21; 5069-UM001N p. 23. The table gives no bank count for the 1768-L43 because the sources differ: 1769-TD005O (p. 39) says 2 banks maximum, 1768-UM001F (p. 73) says 3 banks maximum. The 31-module figure for the 5069-L330ER(M) needs Logix Designer version 30 or later; version 29 limits a project to 16 local modules (1769-SG003A p. 9, note 4). On these figures, 1768-L43 matches 1769-L33ER in memory and 1769 module count. A 1768-L45 system with more than 16 1769 modules does not fit a 1769-L33ER and needs a 1769-L36ERM. Rockwell's product pages (read 27 October 2026) show 1769-L33ER, 1769-L33ERM and 1769-L36ERM as "Active Mature", and 5069-L320ER, 5069-L330ERM and 5069-L340ERM as "Active".

Existing 1769 I/O: keep it local, move it behind a 1769-AENTR, or replace it

CompactLogix 5370 L3: keep the 1769 I/O in place. 1769-SG003A (p. 33) lists 1769 I/O as local I/O for 5370 L3 controllers and for 1768 CompactLogix controllers. Modules and wiring stay, but the bank layout must be checked. In a 1768 system the controller powers up to eight 1769 modules attached directly to its right without a 1769 power supply, and distance ratings are counted from the controller, whereas in a 1769 system they are counted from the power supply (1768-UM001F pp. 18, 74–75). A 5370 L3 system uses a 1769 power supply (1769-PA2, 1769-PB2, 1769-PA4 or 1769-PB4) instead of the 1768-PA3/PB3 (1769-UM021K p. 14), and the controller itself has a power supply distance rating of 4 modules (1769-SG003A p. 14). When re-laying out the banks, check the power supply position and every module's distance rating.

CompactLogix 5380: local I/O is Compact 5000 only. 5069-UM001N (p. 132) states that 5380 local I/O is Compact 5000 modules mounted to the right of the controller. To keep the 1769 I/O, it becomes a remote rack on EtherNet/IP through a 1769-AENTR (5069-UM001N p. 137). This is solution 2 in MIGRAT-PP037A (p. 3): 5380 plus Compact 5000 I/O, retaining the existing 1769 modules as a remote rack. Solution 1 is a full move to 5380 and Compact 5000 I/O. The 1769-AENTR has two copper ports and runs on linear or DLR networks (1769-SG003A p. 37); its product page shows "Active Mature".

Networks: 1768-ENBT, 1768-CNB/CNBR and the serial port

• EtherNet/IP. The 1768-ENBT runs at 10 or 100 Mbps (1768-UM001F p. 42); each module provides 64 CIP connections and 32 TCP/IP connections for messaging, and a controller takes up to two ENBT or EWEB modules (1768-UM001F pp. 40, 42, 44). The new controllers have embedded ports but limit the number of EtherNet/IP nodes in the I/O configuration: 1769-L33ER 32 nodes, 1769-L36ERM 48, 5069-L320ER 40, 5069-L330ER 60 (1769-SG003A pp. 9, 14). Count the drives, HMIs and remote racks in the project before choosing a catalog number. A system that uses two ENBTs to separate the plant network from the machine network can use 5380 Dual-IP mode, which needs Studio 5000 Logix Designer version 29 or later; in this mode the two ports cannot have overlapping IP addresses (1769-SG003A p. 19; 5069-UM001N p. 23).
• ControlNet. The 1768-CNB and 1768-CNBR handle remote I/O, produce/consume with other controllers and messaging on ControlNet; the CNBR adds redundant media (1768-UM001F p. 45). 5370 L3 and 5380 controllers have only Ethernet and USB ports (1769-SG003A pp. 9, 14). For the 1769 ControlNet controllers, Rockwell states that ControlNet connections must be converted to EtherNet/IP (p. 14, footnote 3). The same applies to a 1768 system: I/O adapters, drives and HMIs on ControlNet need EtherNet/IP versions, and partner controllers need an EtherNet/IP port to keep produce/consume. CNBR redundant media can become a DLR ring; see DLR or PRP.
• RS-232 port. 1768-L4x controllers have one RS-232 port (1769-TD005O p. 38). Where a serial link must stay, Rockwell suggests a 5380 with a 5069-SERIAL module (1769-SG003A p. 14), which supports ASCII, Modbus, DF1 and DH485 over RS-232/422/485 (p. 21). On a 5370 L3, use a 1769-ASCII module (ASCII over RS-232/422/485) or a 1769-SM2 module (Modbus RTU) (1769-SG003A p. 21).
• 1768-EWEB (web pages, email, sockets) has no replacement catalog number; that function has to be reviewed separately.

Motion: 1768-M04SE SERCOS to Integrated Motion

A 1768-L43 takes up to two 1768-M04SE modules (4 axes) and a 1768-L45 up to four (8 axes); each module handles 4 axes (1768-UM001F p. 107) and connects to the drives over fiber-optic SERCOS (2198-RM002B p. 13). The 5380 has no SERCOS interface: the supported drive types in 5069-UM001N (p. 221) are only Integrated Motion on EtherNet/IP drives and EtherNet/IP-connected drives. Only controllers with an M in the catalog number run Integrated Motion (1769-SG003A pp. 9, 14).

For Kinetix 6000, 2198-RM002B (pp. 13, 16–17) gives the replacement for the 1768-M04SE: Kinetix 5700 running Integrated Motion through the embedded EtherNet/IP port of a CompactLogix 5370 or 5380. Kinetix 5700 needs Studio 5000 version 26.00 or later (p. 13). Axes are configured again; Rockwell refers to MOTION-AT006 for a side-by-side comparison of SERCOS and EtherNet/IP axis configuration (p. 41), and the tuning methods differ (pp. 42–43). For other SERCOS drive families see Kinetix servo drive migration.

Converting the program

• Software version. Up to version 20 the software was called RSLogix 5000; from version 21 it is Logix Designer (1769-UM021K p. 14). The compatibility table in 1768-UM001F (pp. 13, 17) goes up to RSLogix 5000 version 20.01 with firmware 20.013. 5370 L3 controllers use version 20 for firmware 20, or version 21 or later for firmware 21 or later (1769-UM021K p. 14); L37ERM/L38ERM need version 31 or later (1769-SG003A p. 14). The 5380 needs Logix Designer version 28, 29 or 30 or later depending on the catalog number (p. 9). The project will be opened in a newer version, so have the right version on the programming laptop.
• Changing the controller type. When the controller type is changed, tags, routines and programs remain, but I/O devices that are not compatible with the new controller are deleted from the project (5069-UM001N p. 273). For a 1768 system that means the 1768-ENBT, 1768-CNB, 1768-M04SE with its SERCOS drives, and the local 1769 I/O if moving to 5380, all have to be added again. After the change, verify the project and review every instruction that still references a deleted module; work through the full error list before going to site.
• Memory card. The 1768 uses a 1784-CF128 card (1769-TD005O p. 38), which does not carry over; the new controllers use SD cards (1769-SG003A p. 14).

Checklist before the swap

1. Upload and save the running program and network files if an up-to-date copy is not available (2198-RM002B p. 6).
2. List the controller, the 1768 modules, the number of 1769 modules in each bank and the 1769 power supplies of the extra banks.
3. Count the EtherNet/IP nodes and ControlNet connections in use; identify which devices need EtherNet/IP versions.
4. Record the SERCOS axes, drive and motor catalog numbers; re-select drives using the migration guide for that drive family.
5. Check serial links (HMI, scales, readers) and any 1768-EWEB functions.
6. Choose 5370 or 5380; for 5380, decide whether the 1769 I/O stays behind a 1769-AENTR or is replaced with Compact 5000.
7. Convert the project on the bench, clear every verification error, re-create the I/O and axes, and only then go into the shutdown window.

TDL maintains a number of CompactLogix 1768-L43 and 1768-L45 systems on body makers and packing machines that still run every day.

Need an engineer to survey a running system: send a request