Technical Overview
The OMRON CJ2M-CPU15 and CJ2M-CPU35 are flagship CPU units within the CJ-Series programmable logic controller family, designed to deliver exceptional processing power and scalability for demanding industrial automation tasks. These units integrate a robust 60K-step user memory (for the /15 and /35 variants), a rich set of I/O memory areas, and advanced task management features, making them ideal for applications ranging from discrete manufacturing to process control. With support for up to 40 units per PLC and a wide range of expansion racks, the CJ2M-CPU15/35 ensures seamless integration with OMRON’s extensive I/O and special function modules. The CPU’s built-in indexing registers, cyclic task flags, and comprehensive auxiliary areas provide engineers with the flexibility needed for sophisticated control strategies, while the memory card slot enables easy program transfer and data storage. Below is a detailed breakdown of its core specifications.
Technical Specifications Table
| Item |
Specification (CJ2M-CPU15 / CJ2M-CPU35) |
| User Memory (Program Capacity) |
60K steps (for CJ2M-CPU15/35 variants) |
| I/O Bits |
2,560 bits |
| Maximum Connectable Units (per CPU/Expansion Rack) |
10 units max. per rack; 40 units max. per PLC |
| Maximum Number of Expansion Racks |
3 max. |
| Work Area |
8,192 bits (512 words): W000 to W511 (not for external I/O) |
| Holding Area |
8,192 bits (512 words): H000 to H511 (maintains ON/OFF status across power cycles); H512 to H1535 (reserved for function block instances) |
| Auxiliary Area (Read-Only) |
31,744 bits (1,984 words): A0 to A447; 24,576 bits (1,536 words): A10000 to A11535 |
| Auxiliary Area (Read/Write) |
16,384 bits (1,024 words): A448 to A1471 (Note: A960 to A1471 and A10000 to A11535 not accessible by CPU Bus Units, Special I/O Units, PTs, or older support software) |
| Temporary Area |
16 bits: TR0 to TR15 |
| Timer Area |
4,096 timer numbers: T0000 to T4095 (separate from counters) |
| Counter Area |
4,096 counter numbers: C0000 to C4095 (separate from timers) |
| DM Area |
Special I/O Units: D20000 to D29599 (100 words × 96 units); CPU Bus Units: D30000 to D31599 (100 words × 16 units) |
| EM Area |
32k words/bank × 4 banks max.: E00_00000 to E3_32767 (bits addressable by word or bit; not accessible by older devices) |
| Index Registers |
IR0 to IR15 (for storing PLC memory addresses for indirect addressing; can be task-unique or shared) |
| Cyclic Task Flag Area |
128 flags |
| Memory Card Support |
128 MB, 256 MB, or 512 MB |
| Operating Modes |
PROGRAM (no execution, preparation allowed); MONITOR (execution with online editing and I/O memory changes); RUN (normal operation mode) |
Additional Technical Insights
- Memory Architecture: The CJ2M-CPU15/35 features a 60K-step user memory, which is partitioned for program storage and data handling. The DM and EM areas together provide extensive non-volatile data storage, with the EM area offering up to 4 banks of 32K words each, ideal for large recipe tables or historical data logging.
- Task Management: With 128 cyclic task flags and support for up to 288 tasks (including interrupt tasks), the CPU can handle complex multi-tasking environments. Index registers (IR0 to IR15) allow efficient indirect addressing, optimizing memory access for high-speed loops or table operations.
- I/O and Expansion Flexibility: The system supports a maximum of 2,560 I/O bits, expandable via up to 3 expansion racks (each with up to 10 units). This allows integration of analog I/O, temperature controllers, motion modules, and communication interfaces without sacrificing performance.
- Data Integrity and Retention: The Holding Area (H000 to H511) retains its state during power loss or mode changes, critical for preserving machine status or alarm conditions. The Auxiliary Area provides both read-only system flags and read/write user flags, with special attention to compatibility with CJ2-specific features.
- Memory Card Utility: The built-in memory card slot supports capacities up to 512 MB, enabling easy program transfer, firmware updates, and data logging. This is particularly useful for field upgrades or remote diagnostics.
- Operating Modes and Online Editing: The CPU supports three distinct operating modes—PROGRAM, MONITOR, and RUN—with MONITOR mode allowing online editing of ladder logic and real-time I/O memory adjustments, reducing downtime during maintenance.
What Does Our Clients Say
Mitsubishi MR-J4
Laura Navas
Great product!
2019/12/01
Keyence sensor
EQDR SALES
Original and fast!
2020/02/22