{"product_id":"omron-cj1w-srm21-cj1-series-compobus-s-master-unit","title":"Omron CJ1W-SRM21 CJ1 Series CompoBus\/S Master Unit","description":"\u003ch3\u003eDescription\u003c\/h3\u003e\n\u003cp style=\"color: #2d3748; margin-bottom: 1rem;\"\u003eDesigned for high-speed sub-bus communications within automated systems, the Omron CJ1W-SRM21 facilitates seamless I\/O integration as a dedicated CompoBus\/S Master Unit for CJ-series programmable logic controllers. This module functions as an efficient remote I\/O terminal hub, allowing CJ1 CPU architectures to communicate with up to 32 remote slave terminals. By offloading local I\/O wiring to a localized high-speed bus network, this module significantly reduces physical wiring paths while retaining extremely low I\/O response times. System engineers can dynamically allocate memory allocations between 256 or 128 discrete I\/O points depending on network complexity and cycle time requirements.\u003c\/p\u003e\n\n\u003ch3\u003eFeatures\u003c\/h3\u003e\n\u003cul style=\"list-style-type: square; color: #2d3748; padding-left: 1.5rem; margin-bottom: 1.5rem;\"\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSelectable I\/O Capacity:\u003c\/strong\u003e Supports configuration for either 256 I\/O points (using 20 allocated CIO words) or 128 I\/O points (using 10 allocated CIO words).\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDual Transmission Modes:\u003c\/strong\u003e Easily switch between High-Speed mode (750 kbps for up to 100 meters) and Long-Distance mode (93.75 kbps for up to 500 meters).\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eIntegrated Diagnostics:\u003c\/strong\u003e Dedicated status word flags monitor participation, communication line failures, and individual slave error states.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFlexible Mounting:\u003c\/strong\u003e Fully compatible with CJ1G, CJ1H, and CJ2M CPU racks and expansion racks.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eApplications\u003c\/h3\u003e\n\u003cul style=\"list-style-type: square; color: #2d3748; padding-left: 1.5rem; margin-bottom: 1.5rem;\"\u003e\n  \u003cli\u003eDistributed packaging machinery and conveyor line control.\u003c\/li\u003e\n  \u003cli\u003eMaterial handling sorting systems.\u003c\/li\u003e\n  \u003cli\u003eRemote sensory clusters in industrial assembly cells.\u003c\/li\u003e\n  \u003cli\u003eDecentralized pneumatic valve terminal manifolds.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003cdiv style=\"overflow-x: auto; width: 100%; margin-bottom: 1.5rem;\"\u003e\n  \u003ctable style=\"border-collapse: collapse; width: 100%; color: #2d3748; text-align: left; font-size: 0.9rem;\"\u003e\n    \u003cthead\u003e\n      \u003ctr style=\"border-bottom: 2px solid #2d3748;\"\u003e\n        \u003cth style=\"padding: 0.5rem; font-weight: bold;\"\u003eParameter\u003c\/th\u003e\n        \u003cth style=\"padding: 0.5rem; font-weight: bold;\"\u003eValue\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr style=\"border-bottom: 1px solid #e2e8f0;\"\u003e\n        \u003ctd style=\"padding: 0.5rem; font-weight: bold;\"\u003eManufacturer\u003c\/td\u003e\n        \u003ctd style=\"padding: 0.5rem;\"\u003eOmron Industrial Automation\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr style=\"border-bottom: 1px solid #e2e8f0;\"\u003e\n        \u003ctd style=\"padding: 0.5rem; font-weight: bold;\"\u003eModel Number\u003c\/td\u003e\n        \u003ctd style=\"padding: 0.5rem;\"\u003eCJ1W-SRM21\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr style=\"border-bottom: 1px solid #e2e8f0;\"\u003e\n        \u003ctd style=\"padding: 0.5rem; font-weight: bold;\"\u003eUnit Classification\u003c\/td\u003e\n        \u003ctd style=\"padding: 0.5rem;\"\u003eCJ-series Special I\/O Unit\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr style=\"border-bottom: 1px solid #e2e8f0;\"\u003e\n        \u003ctd style=\"padding: 0.5rem; font-weight: bold;\"\u003eCommunication Protocol\u003c\/td\u003e\n        \u003ctd style=\"padding: 0.5rem;\"\u003eCompoBus\/S\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr style=\"border-bottom: 1px solid #e2e8f0;\"\u003e\n        \u003ctd style=\"padding: 0.5rem; font-weight: bold;\"\u003eMax. Connectable Nodes\u003c\/td\u003e\n        \u003ctd style=\"padding: 0.5rem;\"\u003e32 remote slave terminals\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr style=\"border-bottom: 1px solid #e2e8f0;\"\u003e\n        \u003ctd style=\"padding: 0.5rem; font-weight: bold;\"\u003eAllocated CIO Words\u003c\/td\u003e\n        \u003ctd style=\"padding: 0.5rem;\"\u003e20 words (for 256 I\/O) or 10 words (for 128 I\/O)\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr style=\"border-bottom: 1px solid #e2e8f0;\"\u003e\n        \u003ctd style=\"padding: 0.5rem; font-weight: bold;\"\u003eCurrent Consumption\u003c\/td\u003e\n        \u003ctd style=\"padding: 0.5rem;\"\u003e0.15 A at 5 VDC\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr style=\"border-bottom: 1px solid #e2e8f0;\"\u003e\n        \u003ctd style=\"padding: 0.5rem; font-weight: bold;\"\u003eTransmission Distance\u003c\/td\u003e\n        \u003ctd style=\"padding: 0.5rem;\"\u003e100 m (High-Speed), 500 m (Long-Distance)\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr style=\"border-bottom: 1px solid #e2e8f0;\"\u003e\n        \u003ctd style=\"padding: 0.5rem; font-weight: bold;\"\u003eShipping Weight (Calculated)\u003c\/td\u003e\n        \u003ctd style=\"padding: 0.5rem;\"\u003e0.25 kg\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr style=\"border-bottom: 1px solid #e2e8f0;\"\u003e\n        \u003ctd style=\"padding: 0.5rem; font-weight: bold;\"\u003ePackage Dimensions (Calculated)\u003c\/td\u003e\n        \u003ctd style=\"padding: 0.5rem;\"\u003e15.0 x 10.0 x 4.0 cm\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch3\u003eConnections and Interfaces\u003c\/h3\u003e\n\u003cdiv style=\"overflow-x: auto; width: 100%; margin-bottom: 1.5rem;\"\u003e\n  \u003ctable style=\"border-collapse: collapse; width: 100%; color: #2d3748; text-align: left; font-size: 0.9rem;\"\u003e\n    \u003cthead\u003e\n      \u003ctr style=\"border-bottom: 2px solid #2d3748;\"\u003e\n        \u003cth style=\"padding: 0.5rem; font-weight: bold;\"\u003eTerminal Block Pin\u003c\/th\u003e\n        \u003cth style=\"padding: 0.5rem; font-weight: bold;\"\u003eFunction \/ Signal Assignment\u003c\/th\u003e\n      \u003c\/tr\u003e\n    \u003c\/thead\u003e\n    \u003ctbody\u003e\n      \u003ctr style=\"border-bottom: 1px solid #e2e8f0;\"\u003e\n        \u003ctd style=\"padding: 0.5rem; font-weight: bold;\"\u003eBD H\u003c\/td\u003e\n        \u003ctd style=\"padding: 0.5rem;\"\u003eCompoBus\/S Communications Line (High)\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr style=\"border-bottom: 1px solid #e2e8f0;\"\u003e\n        \u003ctd style=\"padding: 0.5rem; font-weight: bold;\"\u003eBD L\u003c\/td\u003e\n        \u003ctd style=\"padding: 0.5rem;\"\u003eCompoBus\/S Communications Line (Low)\u003c\/td\u003e\n      \u003c\/tr\u003e\n      \u003ctr style=\"border-bottom: 1px solid #e2e8f0;\"\u003e\n        \u003ctd style=\"padding: 0.5rem; font-weight: bold;\"\u003eNC\u003c\/td\u003e\n        \u003ctd style=\"padding: 0.5rem;\"\u003eNo Connection\u003c\/td\u003e\n      \u003c\/tr\u003e\n    \u003c\/tbody\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch3\u003eEmpirical Engineering Insights\u003c\/h3\u003e\n\u003ch4\u003eAlternative Models \u0026amp; Compatibility\u003c\/h4\u003e\n\u003cp style=\"color: #2d3748; margin-bottom: 1rem;\"\u003eThe CJ1W-SRM21 serves as a drop-in replacement for older CompoBus systems and integrates directly onto CJ-series backplanes. Note that if you are migrating from CS-series architectures using CS1W-SRM21, the memory mapping and CIO allocations match conceptually, but the physical form factor of the module is strictly CJ-series. Ensure you verify backplane physical depth limitations when arranging the CJ1W card in high-density control panels.\u003c\/p\u003e\n\n\u003ch4\u003eApplication Pitfalls \u0026amp; Engineering Notes\u003c\/h4\u003e\n\u003cp style=\"color: #2d3748; margin-bottom: 1rem;\"\u003eA common field misconfiguration involves mixing CompoBus\/S slave speeds. All connected slaves on the same trunk network must be configured to the same transmission mode as the CJ1W-SRM21 (either all High-Speed or all Long-Distance). If there is a mismatch, the Master Unit will generate persistent participation flags or fail to establish communication with the misplaced nodes entirely.\u003c\/p\u003e\n\n\u003ch4\u003eCommissioning \u0026amp; Wiring Tips\u003c\/h4\u003e\n\u003cp style=\"color: #2d3748; margin-bottom: 1rem;\"\u003eAlways power cycle the PLC chassis after modifying the front-panel rotary unit number switches or the internal DIP switches. The CJ CPU registers the CJ1W-SRM21 hardware parameters and physical address configurations only during its initial boot sequence. Additionally, ensure that standard 100-ohm terminating resistors are installed at both physical ends of the communication trunk to eliminate signaling echoes and line noise.\u003c\/p\u003e\n\n\u003ch3\u003eInstallation Guidelines\u003c\/h3\u003e\n\u003cdiv style=\"background-color: #fff5f5; border-left: 4px solid #c53030; padding: 1rem; margin-bottom: 1.5rem;\"\u003e\n  \u003cp style=\"color: #9b2c2c; font-weight: bold; margin: 0 0 0.5rem 0;\"\u003eCRITICAL WARNING\u003c\/p\u003e\n  \u003cp style=\"color: #9b2c2c; margin: 0; font-size: 0.9rem;\"\u003eDo not install or remove the CJ1W-SRM21 module while the PLC backplane is powered. Failure to completely isolate power before handling modules can cause catastrophic damage to the CJ-series CPU bus interface, corrupt CPU user memory, or cause intermittent hardware exceptions on adjacent modules.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"margin-bottom: 1.5rem;\"\u003e\n  \u003cdiv style=\"display: flex; align-items: flex-start; margin-bottom: 1rem;\"\u003e\n    \u003cdiv style=\"background-color: #2b6cb0; color: #ffffff; width: 1.8rem; height: 1.8rem; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-weight: bold; flex-shrink: 0; margin-right: 0.75rem;\"\u003e1\u003c\/div\u003e\n    \u003cp style=\"color: #2d3748; margin: 0;\"\u003eIsolate the master power supply supplying the CJ-series backplane and auxiliary field bus networks.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv style=\"display: flex; align-items: flex-start; margin-bottom: 1rem;\"\u003e\n    \u003cdiv style=\"background-color: #2b6cb0; color: #ffffff; width: 1.8rem; height: 1.8rem; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-weight: bold; flex-shrink: 0; margin-right: 0.75rem;\"\u003e2\u003c\/div\u003e\n    \u003cp style=\"color: #2d3748; margin: 0;\"\u003eConfigure the front-panel rotary switch to assign the desired Unit Number (0 to 95) and select the corresponding I\/O configuration via the unit's DIP switches.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv style=\"display: flex; align-items: flex-start; margin-bottom: 1rem;\"\u003e\n    \u003cdiv style=\"background-color: #2b6cb0; color: #ffffff; width: 1.8rem; height: 1.8rem; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-weight: bold; flex-shrink: 0; margin-right: 0.75rem;\"\u003e3\u003c\/div\u003e\n    \u003cp style=\"color: #2d3748; margin: 0;\"\u003eAlign the top and bottom guides of the module with the CJ rack slots and push the module firmly until the lock levers click into place.\u003c\/p\u003e\n  \u003c\/div\u003e\n  \u003cdiv style=\"display: flex; align-items: flex-start;\"\u003e\n    \u003cdiv style=\"background-color: #2b6cb0; color: #ffffff; width: 1.8rem; height: 1.8rem; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-weight: bold; flex-shrink: 0; margin-right: 0.75rem;\"\u003e4\u003c\/div\u003e\n    \u003cp style=\"color: #2d3748; margin: 0;\"\u003eWire the BD H and BD L terminal lines using dedicated twisted-pair CompoBus cable and double-check terminal tighteners to prevent loose physical contacts.\u003c\/p\u003e\n  \u003c\/div\u003e\n\u003c\/div\u003e","brand":"Omron","offers":[{"title":"Default Title","offer_id":53077934702955,"sku":"CJ1W-SRM21","price":100.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0953\/3227\/0443\/files\/cj1w-srm21-bhguy41unl1.png?v=1775733545","url":"https:\/\/www.plcprotech.com\/de\/products\/omron-cj1w-srm21-cj1-series-compobus-s-master-unit","provider":"PLC ProTech Ltd.","version":"1.0","type":"link"}