Omron NJ501-4500 Robotics CPU Unit

Technical Overview

NJ-series Sysmac robotics CPU unit with integrated motion, sequence, and robotics control. The NJ501-4500 supports up to 64 synchronous axes, up to 8 robots, 20 MB program memory, 6 MB variable memory, EtherCAT Master, EtherNet/IP, and USB, with optional industrial network and fieldbus expansion. Manufacturer documentation identifies it as a Robotics CPU Unit for NJ-series machine automation applications.

Key Features

Motion control, robotics, and sequence control in one CPU unit
Up to 64 synchronous axes
Up to 8 robots
0.5 ms primary task cycle time
20 MB program memory
6 MB variables memory
Built-in EtherCAT Master
Built-in EtherNet/IP and USB ports
Supports multiple optional industrial communication protocols
Designed for NJ-series Sysmac automation systems

Technical Specification Matrix

Parameter	Value
Controller functionality	Motion control, Robotics, Sequence control
Max. number of synchronous axes	64
Max. number of axes (incl. virtual)	64
Max. number of robots	8
Primary task cycle time	0.5 ms
Program memory	20 MB
Variables memory	6 MB
Communication port(s)	EtherCAT Master, EtherNet/IP, USB
Communication option(s)	CAN, CompoNet Master, DeviceNet Master, DeviceNet Slave, EtherCAT Slave, MODBUS Master, MODBUS Slave, PROFIBUS DP Master, PROFIBUS DP Slave, PROFINET Master, Serial RS-232C, Serial RS-422, Serial RS-485
Max. number of remote I/O nodes	192
I/O system	CJ I/O Bus
Max. number of expansion units	40
Product Height (unpacked)	96 mm
Product Width (unpacked)	90 mm
Product Depth (unpacked)	150 mm

Industrial Applications

1. High-axis robot cell coordination

Coordinates multi-axis robot cells where synchronized motion and deterministic EtherCAT timing are required for repeatable pick, place, and transfer operations.

Problem Solved

Eliminates timing drift and multi-controller complexity in synchronized robotic cells.

EtherCAT Master64 synchronous axes8 robots0.5 ms cycle time

2. Flexible packaging and palletizing line control

Controls servo-driven packaging and palletizing machines that need both sequence logic and precise motion coordination across many axes.

Problem Solved

Consolidates sequencing and motion into one controller for compact machine architectures.

motion controlsequence controlEtherNet/IPprogram memoryvariable memory

3. Distributed machine automation with remote I/O

Supports large machine systems using up to 192 remote I/O nodes and CJ I/O Bus expansion for coordinated sensing, actuation, and interlocking.

Problem Solved

Reduces wiring complexity while scaling I/O across large automated lines.

192 remote I/O nodesCJ I/O Bus40 expansion unitsindustrial communication