Omron CJ1M-CPU11-ETN Compact CPU Unit with Built-in Ethernet for CJ-Series PLCs
The Omron CJ1M-CPU11-ETN is a compact CPU unit for the SYSMAC CJ-series programmable logic controllers, featuring integrated Ethernet functionality for seamless network integration. This CPU unit combines the processing power of the CJ1M platform with built-in Ethernet communications, eliminating the need for a separate Ethernet unit in many applications. The CJ1M-CPU11-ETN is designed for small to medium automation applications requiring network connectivity, machine control, and flexible I/O configuration, making it suitable for packaging machinery, material handling systems, and assembly equipment.
Key Specifications
Model: CJ1M-CPU11-ETN
Product Series: SYSMAC CJ-series CJ1M CPU Units
I/O Capacity: 160 points maximum
Program Memory: 5 Ksteps (5,120 steps)
Data Memory: 32 Kwords (32,768 words)
LD Instruction Execution Time: 0.1 μs
Maximum Subroutines: 256
Maximum JMP Instructions: 256
Maximum Function Block Definitions: 128
Ethernet Function: Built-in (100BASE-TX, 10BASE-T)
Maximum Units on CPU Rack: 9 units
Expansion Racks: Not supported
Current Consumption (5V): 0.95A
Built-in Ethernet Functionality
The CJ1M-CPU11-ETN incorporates integrated Ethernet functionality, providing the main features of the CJ1W-ETN21 Ethernet Unit directly on the CPU. The built-in Ethernet supports 100BASE-TX and 10BASE-T physical layers, offering compatibility with both fast Ethernet and standard Ethernet networks. The CPU supports FINS communications service for seamless data exchange with other Omron PLCs and devices across the network. The Ethernet function allows connection of up to 254 nodes in a FINS network, providing scalability for expanding automation systems. The built-in FTP server enables file transfer for program backups, data logging, and recipe management.
Compact Dimensions and Space-Saving Design
The CJ1M-CPU11-ETN features compact dimensions of 90 x 65mm (H x D), representing industry-leading space efficiency for CPU units with integrated Ethernet. The small footprint allows installation in space-constrained control cabinets where every millimeter of panel space is valuable. The compact design does not compromise functionality, providing full CJ1M processing capabilities and Ethernet communications in a package that fits easily into OEM machinery and retrofit applications. The reduced size also contributes to lower shipping weight and easier handling during installation.
Program and Data Memory
The CPU provides 5 Ksteps of user program memory, sufficient for small to medium control applications requiring ladder logic, function blocks, and structured programming. The 32 Kwords of data memory (DM) provides ample capacity for data storage, recipe management, and process variable logging. The memory architecture supports efficient program execution with a basic instruction execution time of 0.1 μs for LD instructions, enabling fast scan times even with moderately complex programs. The CPU supports up to 256 subroutines for structured programming, 256 JMP instructions for program flow control, and 128 function block definitions for reusable code components.
I/O Configuration and Expansion
The CJ1M-CPU11-ETN supports a maximum of 160 I/O points, suitable for small to medium machine control applications with moderate I/O requirements. The CPU can accommodate up to 9 units on the CPU rack, allowing configuration of mixed I/O modules including digital inputs, digital outputs, analog I/O, and specialized function modules. Expansion racks are not supported on this model, limiting total system size to the main CPU rack. This limitation makes the CJ1M-CPU11-ETN best suited for applications where all I/O can be accommodated within the CPU rack's capacity.
CJ1M Series Compatibility
The CJ1M-CPU11-ETN is part of the CJ1M family of CPU units, which includes models with varying program memory capacities and I/O capabilities. The CJ1M low-end models (CJ1M-CPU11-ETN and CJ1M-CPU21) have specific specifications for overhead processing time, number of subroutines, number of jumps, and number of scheduled interrupts compared to higher-end CJ1M models. The CPU is compatible with the full range of CJ-series I/O modules and expansion units, providing flexibility in system configuration while maintaining a consistent programming environment across the product family.
SYSMAC CJ-series Platform
The CJ1M-CPU11-ETN is built on the SYSMAC CJ-series platform, Omron's modular PLC system designed for machine automation applications. The CJ-series offers a wide range of CPU units, I/O modules, communication units, and special function modules, allowing users to configure controllers precisely for their application requirements. The platform supports a maximum I/O capacity of 640 points when used with higher-end CJ1M CPUs and expansion racks, providing scalability from small standalone machines to larger distributed systems. The common programming environment across the CJ-series simplifies engineering and training.
Programming and Software Support
The CJ1M-CPU11-ETN is programmed using Omron's CX-Programmer software, part of the Sysmac Studio automation suite. The software supports all IEC 61131-3 programming languages including ladder diagram, structured text, function block diagram, and sequential function chart. Online monitoring capabilities allow real-time observation of program execution and I/O status. The Ethernet port enables remote programming and monitoring, allowing engineers to connect to the PLC from anywhere on the plant network. The software includes tools for network configuration, motion control programming, and data logging setup.
Serial Communication Port
The CPU includes a built-in RS-232C serial port for connection to programming devices, HMIs, and other serial equipment. The serial port supports Host Link protocol for communication with host computers and other Omron devices. A D-SUB 9-pin male connector is provided for serial connection, with a connector set included as an accessory. The serial port can be used for program upload/download, data exchange with HMIs, and connection to barcode readers, printers, and other serial peripherals. An optional NT-AL001 RS-232C/RS-422A adapter can be used for extended distance communication.
Industrial Applications
The Omron CJ1M-CPU11-ETN is deployed across a wide range of industrial automation applications requiring integrated Ethernet connectivity. In packaging machinery, it controls filling machines, sealing equipment, and labeling applicators with network connectivity for production reporting. In material handling, it manages conveyor systems, sortation equipment, and palletizers with Ethernet communication to supervisory systems. In assembly equipment, it coordinates part feeding, assembly operations, and quality testing with remote monitoring capabilities. The CPU's compact size and built-in Ethernet make it particularly suitable for OEM machinery where panel space is limited and network connectivity is required.
Discontinuation Notice
The CJ1M-CPU11-ETN CPU unit was discontinued by Omron in March 2021. Users planning new installations should consider current Omron PLC offerings for ongoing product support and availability. For existing installations, replacement units and repair services may be available through authorized Omron distributors. The documentation and specifications provided reflect the product as manufactured and are intended for reference for existing systems.
Conclusion
The Omron CJ1M-CPU11-ETN compact CPU unit provides integrated Ethernet functionality with 5K steps program memory, 32K words data memory, and support for 160 I/O points. Its compact dimensions and built-in networking make it a practical solution for small to medium machine automation applications requiring network connectivity.





