{"product_id":"omron-cj1w-etn21-ethernet-unit-cj-series","title":"Omron CJ1W-ETN21 Ethernet Unit CJ Series","description":"\u003cp\u003eThe \u003cstrong\u003eOmron CJ1W-ETN21\u003c\/strong\u003e, also cataloged as the \u003cstrong\u003eCJ1W-ETN21\u003c\/strong\u003e Ethernet Unit, operates as a dedicated hardware component for high-speed industrial Ethernet messaging execution within Omron CJ-series PLC systems.\u003c\/p\u003e\n\u003ch3\u003eTechnical Identifier Matrix\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBase Part Number:\u003c\/strong\u003e CJ1W-ETN21\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Omron\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eClassification:\u003c\/strong\u003e CPU Bus Unit\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePhysical Interface:\u003c\/strong\u003e 100BASE-TX (10BASE-T compatible)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTopology:\u003c\/strong\u003e Star network topology\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eHardware Specifications\u003c\/h3\u003e\n\u003cfigure class=\"table\"\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cstrong\u003eParameter\u003c\/strong\u003e\u003c\/th\u003e\n\u003cth\u003e\u003cstrong\u003eSpecification\u003c\/strong\u003e\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003eCJ1W-ETN21\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eOmron\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOrigin\u003c\/td\u003e\n\u003ctd\u003eJapan\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.10 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions\u003c\/td\u003e\n\u003ctd\u003e3.1 cm x 9.0 cm x 6.5 cm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShipping Dimensions\u003c\/td\u003e\n\u003ctd\u003e15.0 cm x 10.0 cm x 5.0 cm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Temp\u003c\/td\u003e\n\u003ctd\u003e0 to 55 deg C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower Consumption\u003c\/td\u003e\n\u003ctd\u003e1.85 W (370 mA at 5 VDC)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCurrent Consumption\u003c\/td\u003e\n\u003ctd\u003e370 mA max at 5 VDC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMedia Type\u003c\/td\u003e\n\u003ctd\u003e100BASE-TX (fallback to 10BASE-T)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModulation Method\u003c\/td\u003e\n\u003ctd\u003eBaseband\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTransmission Topology\u003c\/td\u003e\n\u003ctd\u003eStar form\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTransmission Distance\u003c\/td\u003e\n\u003ctd\u003e100 m (node-to-hub segment limit)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMounting Location\u003c\/td\u003e\n\u003ctd\u003eCPU Rack or Expansion Rack\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003ch3\u003eBackplane Bus Velocity \u0026amp; Firmware Compatibility\u003c\/h3\u003e\n\u003cp\u003eThe \u003cstrong\u003eOmron CJ1W-ETN21\u003c\/strong\u003e interfaces directly with the high-speed CJ-series backplane bus to deliver deterministic FINS messaging and socket communication across industrial Ethernet links. Functioning as a CPU Bus Unit, it routes cyclic I\/O data and explicit message frames directly between the CPU memory structures and field Ethernet nodes without causing PLC scan delay.\u003c\/p\u003e\n\u003cp\u003eHigh backplane throughput supports concurrent socket connections, raw TCP\/UDP data frames, and FTP server functions. Internal flash firmware ensures hardware compatibility across CJ1G, CJ1H, CJ1M, and extended CJ-series CPU processors, maintaining full network frame determinism under high-density I\/O traffic.\u003c\/p\u003e\n\u003ch3\u003ePackage Contents \u0026amp; Ordering Information\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e1x Omron CJ1W-ETN21 Ethernet Unit\u003c\/li\u003e\n\u003cli\u003e1x Hardware Installation Sheet\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eField Installation Guidelines\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eRack Installation:\u003c\/strong\u003e Mount the CJ1W-ETN21 onto the CJ CPU Rack or Expansion Rack DIN rail, pushing horizontally until upper and lower mounting catches lock firmly into position.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNode Setting:\u003c\/strong\u003e Adjust the front-panel rotary switches to assign the CPU Bus Unit number and binary local IP node address before powering the PLC rack.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEthernet Cabling:\u003c\/strong\u003e Route industrial-grade Category 5 or 5e Shielded Twisted-Pair (STP) cabling from the RJ45 port to an industrial Ethernet switch, respecting the 100 m maximum segment limit.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShielding \u0026amp; Grounding:\u003c\/strong\u003e Terminate the RJ45 connector shield to the module frame earth. Ground the CPU Rack functional ground (FG) terminal directly to a protective earth rail using a 2.0 mm sq or larger conductor with a 360-deg braid clamp.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003eWhat is the maximum current consumption of the CJ1W-ETN21?\u003c\/p\u003e\n\u003cp\u003eThe unit draws a maximum of 370 mA at 5 VDC directly from the CJ-series CPU backplane bus.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eCan the CJ1W-ETN21 operate on 10 Mbps networks?\u003c\/p\u003e\n\u003cp\u003eYes, the 100BASE-TX port features auto-negotiation and supports fallback operation on 10BASE-T Ethernet networks.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eWhat is the maximum point-to-point cable distance for the Ethernet connection?\u003c\/p\u003e\n\u003cp\u003eThe maximum transmission distance is 100 m between the CJ1W-ETN21 unit and the network hub or switch.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eCan the CJ1W-ETN21 be mounted on an Expansion Rack?\u003c\/p\u003e\n\u003cp\u003eYes, the module can be located on either the local CPU Rack or any CJ-series Expansion Rack.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eDoes the CJ1W-ETN21 support hot-swapping under backplane power?\u003c\/p\u003e\n\u003cp\u003eNo, power to the rack must be completely disconnected before installing or removing the CPU Bus Unit.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eWhat transmission topology is required for CJ1W-ETN21 network runs?\u003c\/p\u003e\n\u003cp\u003eThe module requires a star network topology utilizing twisted-pair cabling connected to a central switch or hub.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eHow are the internal unit number and node address configured?\u003c\/p\u003e\n\u003cp\u003eThe CPU Bus Unit number and local IP node address are set using rotary switches located on the front panel.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eWhat cabling specifications are recommended for noise mitigation?\u003c\/p\u003e\n\u003cp\u003eUse Category 5 or 5e Shielded Twisted-Pair (STP) cable with 360-deg braid ground connection to protect against EMI.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Omron","offers":[{"title":"Default Title","offer_id":47306666737837,"sku":"CJ1W-ETN21","price":100.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0733\/1613\/9181\/files\/CJ1W-ETN21_1.jpg?v=1788155964","url":"https:\/\/www.maxwellplc.com\/products\/omron-cj1w-etn21-ethernet-unit-cj-series","provider":"Maxwell PLC Ltd","version":"1.0","type":"link"}