OMRON CJ1W-NCF71 Position Control Unit with MECHATROLINK-II Interface
The OMRON CJ1W-NCF71 is a high-performance Position Control Unit (PCU) for the CJ series programmable logic controllers. This advanced module controls up to 16 axes of motion through the MECHATROLINK-II high-speed fieldbus, providing coordinated motion control for multi-axis automation systems. The CJ1W-NCF71 supports position, speed, and torque control modes, enabling flexible architecture for complex machinery including assembly lines, packaging equipment, printing presses, and material handling systems.
Multi-Axis Motion Control
The CJ1W-NCF71 controls up to 16 axes through MECHATROLINK-II synchronous communications, making it suitable for multi-drive systems ranging from simple indexing tables to complex synchronized machine lines. The unit operates as a CPU Bus Unit for CJ-series PLCs, connecting directly to Yaskawa Sigma II and Sigma V servo drives equipped with MECHATROLINK-II interfaces. For multi-axis systems, from machine design through future expansion, control systems can be conveniently changed at any time using the position control unit.
Control commands are executed by MECHATROLINK-II synchronous communications, providing deterministic timing required for coordinated multi-axis operations including electronic gear, electronic cam, linear interpolation, and circular interpolation. The synchronous communication ensures that each axis receives its command data simultaneously, eliminating drift between axes during long-duration coordinated moves.
The unit supports direct operation by ladder programming, allowing motion control commands to be initiated from standard PLC logic without extensive motion-specific programming expertise. This integration simplifies application development and maintenance for machine builders familiar with standard PLC programming but requiring advanced motion capabilities.
Control Modes and Capabilities
The CJ1W-NCF71 provides three primary control modes to match application requirements. Position control positions to absolute or relative targets defined by the ladder program, indexing tables, or CAM profiles, with interpolation providing smooth coordinated moves. Speed control precisely regulates motor velocity based on programmed setpoints, suitable for conveyor tracking, spindle control, and web handling applications. Torque control commands specific motor torque outputs, appropriate for tension control, pressing operations, and load sharing configurations.
Control mode selection can be changed during operation, allowing systems to transition between position, speed, and torque as the machine cycle progresses. For example, a pick-and-place operation might use speed control during transport and position control for final part placement.
Installation and Communication
The CJ1W-NCF71 mounts into CJ series CPU racks as a dedicated CPU Bus Unit, allocating 2 unit numbers and consuming 0.36 A at 5 VDC from the backplane. The MECHATROLINK-II network operates over standard shielded twisted-pair cables using MECHATROLINK-II cables manufactured by Yaskawa Corporation, available in lengths from 0.5 to 30 meters. A repeater (JEPMC-REP2000-E) can extend network distance for larger machine layouts. For network termination, the FNY-W6022 terminating resistor is required at each physical end of the network trunk line.
For software configuration, the CJ1W-NCF71 is supported by CX-One software package, which integrates CX-Motion-NCF motion control configuration tools. This software allows parameter setting, point table creation, cam profile generation, diagnostic access, and program development for motion applications. The unit also supports batch setting and management of servo drive parameters, allowing configuration and adjustment from the PLC without separately programming each servo amplifier.
System Compatibility and Applications
The CJ1W-NCF71 works with OMNUC W series AC servo drives with built-in MECHATROLINK-II communication, including models compatible with the unit. Please note the unit cannot be used with the Machine Automation Controller NJ-series; it is designed specifically for CJ-series CPUs. The system reduces controller volume to as small as 2/3 or less of previous configurations while simplifying cabling to a single MECHATROLINK-II cable for both command and response data.
The unit supports initial setup and maintenance time savings because servo drive parameters can be set from the PLC. Monitoring of servo drive alarm status and information such as velocity and torque is possible from the PLC, eliminating the need to connect programming devices to each servo drive.
For simpler systems, the CJ1W-NCF71 provides flexible configuration from a few axes to the full 16-axis capacity. This expandability allows machine builders to design scalable product lines supporting capacity upgrades as production requirements increase. The compact size of 31 x 90 mm makes this PCU space-efficient for crowded control panels. The unit meets UC1, CE, and other international standards for global deployment.
