Omron CJ1W-ETN21 CJ Series Ethernet Unit 100BASE-TX

Omron CJ1W-ETN21 is an Ethernet communication unit for the SYSMAC CJ series PLC system. 100BASE‑TX (auto‑negotiation, also usable as 10BASE‑T). Single RJ45 port. Mounts on CPU Rack or Expansion Rack via the CJ I/O bus. Supports TCP/IP, UDP/IP (socket services, up to 16 simultaneous connections, 8 each for UDP and TCP), FINS message communication, FTP server, mail transmission (SMTP) and mail reception.

Applications:

• Factory Ethernet networking of CJ series PLCs for data exchange and monitoring

• Connection to SCADA, host computers and HMI systems via TCP/IP or UDP/IP

• PLC program upload/download and remote maintenance via CX‑Programmer

• Email alarm notification and FTP data file transfer

• Integration of CJ systems into existing Ethernet networks

Core Specifications:

• Compatibility: CJ series PLCs (CPU Bus Unit)

• Mounting location: CPU Rack or Expansion Rack

• Maximum units per system: up to 4 (including Expansion Racks)

• Interface: 1 × RJ45, 100BASE‑TX / 10BASE‑T (auto‑negotiation)

• Transmission distance: up to 100 m between hub and node

• Communication protocols: TCP/IP, UDP/IP, FINS (UDP/IP or TCP/IP), FTP server, SMTP, POP3, SNTP

Advanced Specifications:

• Socket services: up to 16 simultaneous connections (8 TCP + 8 UDP)

• FINS message communication with host applications and CX‑Programmer

• Email transmission and reception (remote command receive)

• FTP server for PLC data file transfer

• SNTP automatic time synchronisation (requires SNTP server)

• IP address setting: default IP follows Node number setting (e.g., 192.168.250.Node)

• I/O word allocation: 10 words

• Internal current consumption: 5 V DC, 0.37 A

• Dimensions (W × H × D): 31 mm × 90 mm × 101 mm

• Weight: approx. 150 g

System Integration:

• This unit belongs to the Omron SYSMAC CJ series CPU Bus Units.

• Installs to the left or right of the CPU unit on the CPU Rack, or on Expansion Racks.

• Configuration performed in CX‑Programmer (I/O Table and Unit Setup).

• CX‑Programmer network access via FINS/UDP or FINS/TCP is supported.

• IP address is set in the Unit Setup. The default address is 192.168.250.Node.

Product Status:
Discontinued as of 31 March 2025. Refer to manufacturer documentation for replacement options.

Related Products:

• CJ1W‑EIP21S – EtherNet/IP unit, possible successor with enhanced protocol support

• NX102‑9000 – Sysmac NX1 machine automation controller with built‑in EtherNet/IP and EtherCAT（alternative to CPU+ETN21 systems）

• CJ1W‑EIP21 – EtherNet/IP unit, also discontinued 31 March 2025

• CS1W‑ETN21 – CS series equivalent Ethernet unit