Omron CJ-Series PLCs — CJ2H, CJ2M, CJ1W & CJ3M
The Omron CJ-series is the mid-range rack PLC family: more I/O and faster scan than the CP-series compact line, with CJ2H and CJ2M CPU heads and CJ1W CPU Bus and Special I/O units on the same rack. Every CJ2 CPU supports up to 2,560 I/O points, up to 40 units and 3 expansion racks. We hold 74 CJ-series SKUs in Xiamen.
Lifecycle status
Mixed — the CJ2H-CPU6□-EIP and CJ2M-CPU3□ are discontinued; the CJ3M is current
Omron's discontinuation database records CJ2H-CPU6-EIP and CJ2M-CPU3 with an end-of-production date of 31 May 2023. Omron's designated replacements are CJ2H-CPU6 plus a CJ1W-EIP21S EtherNet/IP unit, and CJ2M-CPU1 plus CJ1W-EIP21S respectively — the network function moved from the CPU onto a separate unit. Current-generation CJ3M CPUs are in production with 5K to 100K steps and up to 5,120 I/O points.
What to fit instead: CJ2H-CPU6 + CJ1W-EIP21S for the -EIP models; CJ2M-CPU1 + CJ1W-EIP21S for CJ2M-CPU3□; CJ3M for new builds
Key specifications
- CJ2H CPUs: 2,560 I/O points, 40 units, 3 expansion racks, LD instruction execution 16 ns
- CJ2H program capacity steps by model — CPU64-EIP 50K, CPU65-EIP 100K, CPU66-EIP 150K, CPU67-EIP 250K, CPU68-EIP 400K
- CJ2M CPUs: same 2,560 I/O point ceiling and 40-unit limit, 40 ns execution, with or without built-in EtherNet/IP
- CJ2M program capacity steps by model — CPU31 5K, CPU32 10K, CPU33 20K, CPU34 30K, CPU35 60K
- CJ1W power supply units: CJ1W-PA202 (100-240 VAC, 14 W), CJ1W-PA205R (100-240 VAC, 25 W, RUN output), CJ1W-PD022 (24 VDC, 19.6 W), CJ1W-PD025 (24 VDC, 25 W)
- CJ2M Pulse I/O modules CJ2M-MD211 and CJ2M-MD212 mount on the left of the CPU — up to two modules, four positioning axes in total
How to read a CJ-series CPU model number
The suffix tells you the program capacity and whether the Ethernet port is built in. These two facts decide which CPU you can actually fit.
| Model | Program capacity | EtherNet/IP | LD execution |
|---|---|---|---|
| CJ2H-CPU68-EIP | 400K steps | Built in | 16 ns |
| CJ2H-CPU67-EIP | 250K steps | Built in | 16 ns |
| CJ2H-CPU66-EIP | 150K steps | Built in | 16 ns |
| CJ2H-CPU65-EIP | 100K steps | Built in | 16 ns |
| CJ2H-CPU64-EIP | 50K steps | Built in | 16 ns |
| CJ2H-CPU64 / 65 / 66 / 67 | 50K to 250K steps | None — add CJ1W-EIP21S | 16 ns |
| CJ2M-CPU35 / 34 / 33 / 32 / 31 | 60K / 30K / 20K / 10K / 5K steps | Built in | 40 ns |
| CJ2M-CPU15 / 14 / 13 / 12 / 11 | 60K / 30K / 20K / 10K / 5K steps | None — add CJ1W-EIP21S | 40 ns |
The -EIP suffix means the EtherNet/IP port is on the CPU. Plain CJ2H and CJ2M-CPU1□ models have no Ethernet port at all — you add a CJ1W-EIP21S unit in a CPU Bus slot.
Omron's replacement path for discontinued CJ models
| Discontinued model | End of production | Omron's designated replacement |
|---|---|---|
| CJ2H-CPU6-EIP | 31 May 2023 | CJ2H-CPU6 + CJ1W-EIP21S |
| CJ2M-CPU3□ (CPU31 to CPU35) | 31 May 2023 | CJ2M-CPU1□ (CPU11 to CPU15) + CJ1W-EIP21S |
Source: Omron China discontinuation and replacement database. The substitution is not like-for-like on networking — the EtherNet/IP function moves off the CPU onto a CJ1W-EIP21S unit, so the I/O table and cabling change.
Moving from a CS1 system to CJ
CJ-series migration from CS1 is real but partial, and Omron documents the exceptions. Many CJ1W Basic I/O units can be used on a CS1 backplane, which lets a mixed CS/CJ fleet share a spares pool. However Omron's own CS/CJ practice guide requires the CS1W-CLK53, CS1W-B7A22, CS1W-PDC55 and CS1W-PTS55 units to stay in a CS-series expansion rack rather than being replaced. Migration is a phased procedure in CX-Programmer, not a drop-in swap: you read the program and I/O table from the existing system, rebuild the configuration, replace the units, then transfer and test. Confirm the specific part number against the CS1 System Manual before ordering.
Where these parts get used
- Mid-size packaging machines combining CJ1W position control units (NC413 / NC433 / NCF71) with CJ1W temperature control (TC001 / TC003) and a CJ1W serial unit driving Modbus-RTU inverters
- Water-treatment SCADA where a CJ2H-CPU64-EIP polls remote I/O blocks over EtherNet/IP while a CP1L handles a separate pump-station front end over serial
- Automotive body-in-white lines where a CJ2M CPU drives servo axes through up to two CJ2M-MD211/MD212 Pulse I/O modules and a CJ1W-CT021 high-speed counter reads a weld-gun position encoder
Which model do you need
- Choose a CJ2H with built-in EtherNet/IP (the -EIP suffix) for new builds — the network port is on the CPU and no extra unit is needed.
- Choose a CJ2M-CPU11 to CPU15 when the machine does not need EtherNet/IP and you want a lower-cost CPU; add CJ1W-EIP21S only if the network demands it.
- Choose the CP-series instead when the panel needs fewer than about 60 I/O points and a smaller footprint.
- If your existing unit is a CJ2H-CPU6-EIP or CJ2M-CPU3□, budget for the CJ1W-EIP21S unit as well as the CPU — the replacement is a pair, not a single part.
All 74 Omron CJ-Series PLCs SKUs
Every part number below links to its own page with full specifications, compatibility notes and stock status.
CJ1M-CPU12CJ1M-CPU21CJ1W-AD04UCJ1W-AD081-V1CJ1W-BAT01CJ1W-CIF11CJ1W-CPU22CJ1W-CT021CJ1W-DA041CJ1W-DA08CCJ1W-DA08VCJ1W-DRM21CJ1W-EIP21CJ1W-ETN21CJ1W-IA111CJ1W-IC101CJ1W-ID201CJ1W-ID211CJ1W-ID212CJ1W-ID231CJ1W-ID232CJ1W-ID261CJ1W-ID262CJ1W-II101CJ1W-MAD42CJ1W-MD232CJ1W-NC233CJ1W-NC413CJ1W-NCF71CJ1W-OC201CJ1W-OC211CJ1W-OD202CJ1W-OD212CJ1W-OD231CJ1W-OD232CJ1W-OD261CJ1W-OD262CJ1W-PA202CJ1W-PA205RCJ1W-PD022CJ1W-PD025CJ1W-PNT21CJ1W-PRM21CJ1W-SCU21-V1CJ1W-SCU22CJ1W-SCU31-V1CJ1W-SCU32CJ1W-SCU42CJ1W-SRM21CJ1W-TC001CJ1W-TC002CJ1W-TC102CJ1W-TS562CJ2-SeriesCJ2H-CPU64CJ2H-CPU64-EIPCJ2H-CPU64EIPCJ2H-CPU65-EIPCJ2H-CPU65EIPCJ2H-CPU66CJ2H-CPU66-EIPCJ2H-CPU67-EIPCJ2H-CPU68-EIPCJ2M-CPU11CJ2M-CPU12CJ2M-CPU13CJ2M-CPU14CJ2M-CPU15CJ2M-CPU31CJ2M-CPU32CJ2M-CPU33CJ2M-CPU34CJ2M-CPU35CJ2M-MD211
Frequently asked
Are the CJ2H-CPU6-EIP and CJ2M-CPU3 CPUs still in production?
No. Omron's discontinuation database records an end-of-production date of 31 May 2023 for CJ2H-CPU6-EIP and CJ2M-CPU3□. The designated replacements are CJ2H-CPU6 plus a CJ1W-EIP21S EtherNet/IP unit, and CJ2M-CPU1□ plus CJ1W-EIP21S. The current-generation successor in the CJ family is the CJ3M.
What is the difference between CJ2H-CPU64-EIP and CJ2H-CPU64?
The -EIP suffix means EtherNet/IP and Ethernet TCP/IP are built into the CPU. The plain CJ2H-CPU64 has only a serial RS-232C port and a USB programming port. Both have 50K steps of program capacity and 2,560 I/O points.
How much program capacity does a CJ2M-CPU14 have?
20K steps. Across the CJ2M-CPU1□ range the capacities are CPU11 5K, CPU12 10K, CPU13 20K, CPU14 30K and CPU15 60K steps. The CJ2M-CPU3□ range mirrors this: CPU31 5K through CPU35 60K steps.
Do CJ2M CPUs have built-in input and output points?
No. A CJ2M CPU unit has no built-in digital I/O. Positioning and fast pulse I/O come from optional CJ2M-MD211 or CJ2M-MD212 Pulse I/O modules, which mount on the left side of the CPU. Up to two modules can be fitted, giving two pulse outputs each — four positioning axes in total.
Can I fit CJ1W I/O units into an NX rack?
No. The NX series uses an EtherCAT-based I/O terminal architecture with a flat-cable bus, not the CJ backplane connector. CJ1W units will not physically or electrically mount to an NX rack — use NX-series I/O units or a remote coupling instead.
Is a CJ-series system backward compatible with CS1?
Partly. Many CJ1W Basic I/O units can be used on a CS1 backplane, so a mixed fleet can share spares. But Omron's own migration guide requires CS1W-CLK53, CS1W-B7A22, CS1W-PDC55 and CS1W-PTS55 units to remain in a CS-series expansion rack, and migration is a phased CX-Programmer procedure rather than a drop-in swap.
What does the -EIP suffix mean on a CJ2 CPU?
It means the CPU unit has a built-in EtherNet/IP port. Without the suffix — CJ2H-CPU64, CJ2M-CPU11 and similar — the CPU has no Ethernet port at all, and you add a CJ1W-EIP21S EtherNet/IP unit to the CPU Bus to get networking.
Specification sources
Specifications on this page were checked against Omron's own documentation. If a figure here disagrees with your datasheet, the datasheet wins — tell us and we will correct it.
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