{"product_id":"abb-tu841-s800-i-o-redundant-modem-termination-unit","title":"ABB TU841 S800 I\/O Redundant Modem Termination Unit","description":"\u003ch2\u003eABB TU841 (3BSE020848R1) S800 I\/O Module Termination Unit\u003c\/h2\u003e\n\u003cp\u003eThe \u003cstrong\u003eTU841\u003c\/strong\u003e (Part Number 3BSE020848R1) is a Module Termination Unit (MTU) engineered by ABB for the S800 I\/O system within the System 800xA automation platform. It is designed to bridge redundant Optical ModuleBus modems, such as the TB840 and TB840A, with non-redundant I\/O modules, enabling fault-tolerant data transmission in distributed control architectures.\u003c\/p\u003e\n\u003ch3\u003eSystem Interconnection and Addressing\u003c\/h3\u003e\n\u003cp\u003eThe unit provides physical connection points for a primary power supply, one electrical ModuleBus, and dual optical modems to maintain redundant communication pathways. Cluster addressing is configured via an integrated rotary switch supporting positions 1 through 7, allowing precise network node identification within the control framework.\u003c\/p\u003e\n\u003ch3\u003eMechanical Keying and Installation\u003c\/h3\u003e\n\u003cp\u003eTo prevent incorrect module insertion during maintenance or commissioning, the TU841 incorporates a mechanical keying system using four keys across six available positions, yielding 36 unique keying configurations. Housed in a standard modular enclosure designed for DIN rail mounting, the unit measures 160 mm x 160 mm x 120 mm with a net weight of 0.8 kg.\u003c\/p\u003e\n\u003ch3\u003eTechnical 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\u003eTU841\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePart Number\u003c\/td\u003e\n\u003ctd\u003e3BSE020848R1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eManufacturer\u003c\/td\u003e\n\u003ctd\u003eABB\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct Series\u003c\/td\u003e\n\u003ctd\u003eS800 I\/O \/ System 800xA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct Type\u003c\/td\u003e\n\u003ctd\u003eModule Termination Units\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePrimary Function\u003c\/td\u003e\n\u003ctd\u003eMTU for redundant TB840\/TB840A modems with non-redundant I\/O\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModuleBus Connections\u003c\/td\u003e\n\u003ctd\u003e1 electrical ModuleBus, 2 optical modems (TB840\/TB840A)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCluster Addressing\u003c\/td\u003e\n\u003ctd\u003eRotary switch (positions 1–7)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMechanical Keying\u003c\/td\u003e\n\u003ctd\u003e4 keys (2 per position, 6 positions each, 36 configurations)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMounting Type\u003c\/td\u003e\n\u003ctd\u003eDIN rail mounting\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions (L x W x H)\u003c\/td\u003e\n\u003ctd\u003e160 mm x 160 mm x 120 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.8 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCountry of Origin\u003c\/td\u003e\n\u003ctd\u003eGermany \/ Spain \/ United States\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003eQ: What is the primary application of the ABB TU841 module termination unit? A: The TU841 connects redundant optical ModuleBus modems (TB840 or TB840A) to non-redundant S800 I\/O modules, ensuring reliable communication in distributed control systems.\u003c\/p\u003e\n\u003cp\u003eQ: How is cluster addressing configured on this MTU? A: Cluster addresses are set using an onboard rotary switch adjustable from position 1 to 7.\u003c\/p\u003e\n\u003cp\u003eQ: What mechanism prevents improper module insertion? A: The unit features a mechanical keying system with 4 keys across 6 positions, providing 36 distinct configurations to secure correct module placement.\u003c\/p\u003e","brand":"ABB","offers":[{"title":"Default Title","offer_id":43775060344931,"sku":"TU841","price":676.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0583\/5246\/8067\/files\/148._5e7a05c7-801d-449f-80af-ea4307740464.jpg?v=1792982806","url":"https:\/\/www.autocontrolglobal.com\/products\/abb-tu841-s800-i-o-redundant-modem-termination-unit","provider":"AutoControl Global","version":"1.0","type":"link"}