Omron CJ1W-EIP21S CJ-Series EtherNet/IP CPU Bus Unit

Technical Overview

The Omron CJ1W-EIP21S is a high-performance EtherNet/IP Unit designed as a CPU Bus Unit for CJ-series, NJ-series, and CP1H Programmable Controllers. It facilitates seamless multivendor industrial network communications using the global standard CIP protocol. This upgraded module features multi-layered network security, including IP packet filtering, user authentication, and port opening/closing functions to protect systems against cyber threats. It supports large-capacity tag data links up to 184,832 words across 256 connections, allowing efficient, programming-free data sharing. Additionally, it offers FINS/UDP, FINS/TCP, and Socket service capabilities for integrated control architectures.

Key Features

Supports large-capacity tag data links to exchange data with up to 256 nodes over up to 256 connections [1.1].
Data capacity of up to 722 words per connection with a maximum of 184,832 words of link data total.
Provides secure communications via user authentication, port open/close functions, and IP packet filtering.
Supports FINS/UDP, FINS/TCP, and Socket service functionality for versatile network integration.
Operates at 100 Mbit/s (100Base-TX) over shielded twisted-pair (STP) Ethernet cabling.
Data concurrency is strictly maintained within each connection for up to 722 words.
Configuration, monitoring, and error diagnostics are seamlessly supported by Omron Network Configurator and Sysmac Studio.

Technical Specification Matrix

Parameter	Value
Unit Classification	CJ-series CPU Bus Unit
Applicable PLCs	NJ-series, CJ1, CJ2, and CP1H series
Baud Rate	100 Mbit/s (100Base-TX)
Current Consumption	650 mA max. at 5V
Maximum Data Link Connections	256 connections
Maximum Tag Data Link Capacity	184,832 words
Max Words Per Connection	722 words
Transmission Distance	100 m (between hub and node)
Weight	91 g max.

Industrial Applications

1. Secure Factory Automation Network Retrofit

Integrating legacy CJ1/CJ2 PLC setups into modern IT and MES networks poses significant cybersecurity risks. The CJ1W-EIP21S mitigates these vulnerabilities by acting as a secure EtherNet/IP gateway. Using its built-in IP packet filtering, user authentication, and port-closing capabilities, the module securely transmits production data to SCADA systems without exposing the local control network to unauthorized access.

Problem Solved

Resolves security vulnerabilities when bridging legacy operational technology (OT) with modern IT networks by deploying onboard cyber-defenses directly at the PLC communication module level.

CybersecurityIP Packet FilteringOT/IT ConvergenceMES IntegrationEtherNet/IP Gateway

2. High-Speed Multi-Node Material Handling

Large-scale automated warehouses require synchronized communication between dozens of VFDs, I/O blocks, and distributed CP1H/CJ2 controllers. The CJ1W-EIP21S manages cyclic tag data link communications across up to 256 nodes. By maintaining data synchronicity within connections (up to 722 words), it ensures highly deterministic start/stop operations across the conveyor lines without requiring complex messaging code.

Problem Solved

Eliminates the need for cumbersome FINS message programming and routing to coordinate widespread nodes, leveraging simple tag configurations for high-speed cyclical coordination.

Tag Data LinksMulti-Node NetworkData SynchronicityCyclic CommunicationsDistributed I/O

3. Large-Capacity Batch Process Parameter Transfer

Chemical and food & beverage batch manufacturing relies on vast recipe parameters and interlocking process variables. The CJ1W-EIP21S solves high-volume data demands by supporting an enormous tag data link capacity (up to 184,832 words). This allows the central NJ-Series or CJ2 controller to push heavy recipe data files down to decentralized equipment while continuing to process standard FINS/TCP status queries simultaneously.

Problem Solved

Overcomes network data constraints in batch operations, providing the required high-capacity payload capabilities to process extensive machine recipes without choking the communications line.

Batch ProcessingRecipe ManagementHigh-Capacity Tag LinksFINS/TCP100Base-TX