Omron CJ1G-CPU43H High-Performance CPU Unit for SYSMAC CJ-Series PLCs
Product Overview
The Omron CJ1G-CPU43H is a high-performance CPU unit belonging to the SYSMAC CJ-series programmable logic controller family. Designed for applications requiring extensive I/O capacity, fast processing, and large memory, this CPU is ideal for complex machine control, process automation, and factory-wide systems. The CJ1G-CPU43H balances substantial program memory (30K steps) and data memory (128K words) with a powerful processing engine that executes basic instructions in just 0.04 µs. It is suitable for demanding environments such as automotive assembly lines, packaging machinery, and semiconductor manufacturing equipment.
Key Specifications
Model: CJ1G-CPU43H
Product Series: SYSMAC CJ-series CJ1G CPU Units
Program Capacity: 30K steps (30,000 steps)
Data Memory (DM): 32K words
Extended Data Memory (EM): 32K words × 3 banks (96K words total)
Total Data Memory: 128K words
I/O Capacity: 1,280 points (max.)
Maximum Mountable Units: 40 units (CPU rack + expansion racks)
Maximum Expansion Racks: 3 racks
LD Instruction Execution Time: 0.04 µs
Function Blocks: Up to 1024 definitions, 2048 instances
Built-in Communication Ports: RS-232C (9-pin D-sub)
Current Consumption (5V DC): 0.82 A
Operating Temperature: 0°C to 55°C
Storage Temperature: -20°C to 75°C
Dimensions (W×H×D): 35 × 90 × 65 mm (approx.)
Weight: 0.2 kg (0.44 lb)
High-Speed Processing for Complex Logic
The CJ1G-CPU43H delivers exceptional performance with a basic instruction time of 0.04 µs (~400 ns) and a common processing time of 0.3 ms. This speed allows the CPU to handle large ladder logic programs, extensive function block usage, and high-speed I/O updates without scan time constraints. The fast execution is crucial for applications requiring rapid response to input changes, such as high-speed packaging equipment and motion control systems.
Ample Memory for Advanced Applications
With 30K steps of program memory and 128K words of combined DM/EM data memory, the CJ1G-CPU43H provides ample storage for complex control sequences, recipe data, process variables, and production logging. The EM (Extended Memory) is partitioned into 3 banks of 32K words each, enabling structured data handling and easy separation of different data sets (e.g., product recipes, machine parameters, historical logs).
Large I/O Capacity and Modular Expansion
The CPU supports up to 1,280 I/O points, accommodating large-scale automation systems with hundreds of sensors and actuators. Up to 40 units (including I/O modules, Special I/O units, and CPU Bus units) can be mounted on the CPU rack and up to 3 expansion racks. This modular architecture allows users to build a system that precisely matches their application requirements, from local I/O to distributed remote I/O via fieldbus.
Function Block Support for Structured Programming
The CJ1G-CPU43H supports function block programming, a key feature for creating reusable, encapsulated code modules. With up to 1,024 function block definitions and 2,048 instances, engineers can develop complex algorithms (e.g., PID control, axis positioning) once and reuse them across multiple machines or projects. This reduces development time, improves code consistency, and simplifies maintenance.
Built-in RS-232C Communication
The CPU includes a built-in RS-232C port (9-pin D-sub) that supports Host Link (Omron’s proprietary protocol), 1:1 NT Link (for HMI connection), and no-protocol communication. This port can be used for programming (CX-Programmer), connection to operator panels, barcode readers, or other serial devices. For plant-wide networking, the CPU can be paired with optional Ethernet, Controller Link, or DeviceNet units.
System Integration and Expandability
The CJ1G-CPU43H is fully compatible with the full range of CJ-series I/O modules (digital, analog, temperature, high-speed counter) and CPU Bus units (Ethernet, Profibus, Serial Gateway). The CPU also supports advanced motion control via EtherCAT coupler units (NX-ECC) or dedicated position control units (CJ1W-NC). The open architecture allows seamless integration with Omron’s Sysmac Studio software and CX-One automation suite.
Industrial Applications
High-performance packaging machinery (filling, sealing, cartoning)
Automotive assembly lines (press controls, conveyor synchronization)
Semiconductor manufacturing equipment (wafer handling, inspection)
Large-scale material handling and sortation systems
Pharmaceutical production (batch control, track and trace)
Conclusion
The Omron CJ1G-CPU43H CPU unit combines high-speed processing, generous memory, and extensive I/O capacity in a compact, rack-based package. Its support for function blocks, scalable expansion, and built-in serial communication make it a versatile and powerful choice for demanding industrial automation applications.





