Key facts
- Brand
- Omron
- Model
- CS1W-ETN21
- Category
- Automation control Equipment
- Industry
- Industrial
- Documents
- 3
- Languages
- EN
- Last added
- 2026-09-30
Start here

Omron CS1W-ETN21 & CJ1W-ETN21 Ethernet Units Operation Manual
This manual explains how to install, configure, and operate the Omron CS1W-ETN21 and CJ1W-ETN21 Ethernet Units. It is intended for engineers and technicians who need to build Ethernet networks for Omron PLC systems.
The document covers unit features, system configuration, wiring, IP address setup, FINS communications, web functions, and detailed troubleshooting procedures, along with reference tables and appendices for advanced settings.
Omron CS1W-ETN21 specifications
| Model number | CS1W-ETN21 |
|---|---|
| Type | 100Base‑TX (Can be used as 10Base‑T) |
| Baud rate | 100 Mbit/s (100Base‑TX) / 10 Mbit/s (10Base‑T) |
| Transmission distance | 100 m (hub‑to‑node) |
| Current consumption | 380 mA max at 5 V DC |
| Maximum units per rack | 4 units |
| Media access method | CSMA/CD |
Source: Omron CS1W-ETN21 & CJ1W-ETN21 Ethernet Units Operation Manual
All Omron CS1W-ETN21 documents by type
Day-to-day operation, settings and troubleshooting. Start here if the product is already set up.
Questions answered in these manuals
How can I confirm the unit version of an Ethernet Unit?
Use CX‑Programmer version 4.0 and open the Unit Manufacturing Information dialog to view the unit version.
From: Omron CS1W-ETN21 & CJ1W-ETN21 Ethernet Units Operation Manual
What is the maximum current consumption of the Ethernet Unit?
The unit consumes up to 380 mA at 5 V DC.
From: Omron CS1W-ETN21 & CJ1W-ETN21 Ethernet Units Operation Manual
How can I confirm the unit version of an Ethernet Unit?
Use CX‑Programmer version 4.0 and open the Unit Manufacturing Information dialog to view the Unit Version Number.
From: Omron CS1W-ETN21 / CJ1W-ETN21 Ethernet Units Construction of Networks User Manual
What label is provided to differentiate Ethernet Units with different unit versions?
A unit‑version label is supplied that can be attached to the front of the Ethernet Unit.
From: Omron CS1W-ETN21 / CJ1W-ETN21 Ethernet Units Construction of Networks User Manual
