{"product_id":"1794-tb3s-allen-bradley-flex-i-o-series-terminal-base-unit","title":"1794-TB3S Allen-Bradley FLEX I\/O Series Terminal Base Unit","description":"\u003cp\u003eConfigured for signal or control execution in industrial systems, the \u003cstrong\u003eAllen-Bradley 1794-TB3S\u003c\/strong\u003e (\u003cstrong\u003e1794-TB3S\u003c\/strong\u003e Terminal Base Unit) provides direct electrical or data interface functions. The hardware serves as the supporting connection block for modular distributed I\/O modules, establishing proper terminal landing paths for field sensors and actuators while passing data along the passive internal communication bus.\u003c\/p\u003e\n\u003ch3\u003eHardware Designation Breakdown\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e1794\u003c\/strong\u003e: Platform prefix denoting the modular FLEX I\/O hardware system architecture.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e-TB3S\u003c\/strong\u003e: Suffix configuration specifying a 3-wire spring-clamp termination layout block.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e\/A\u003c\/strong\u003e: Revision track tracking the current internal structural layout standard.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eTechnical Parameters\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\u003e1794-TB3S\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eAllen-Bradley\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOrigin\u003c\/td\u003e\n\u003ctd\u003eUSA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e0.2 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShipping Dimensions\u003c\/td\u003e\n\u003ctd\u003e10.2 x 7.6 x 10.2 cm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Temperature\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\u003ePassive bus interface (draw limited by the mounted module)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVoltage Rating\u003c\/td\u003e\n\u003ctd\u003e125 VAC\/DC maximum\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCurrent Rating\u003c\/td\u003e\n\u003ctd\u003e10 A maximum\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFrequency\u003c\/td\u003e\n\u003ctd\u003e50\/60 Hz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eI\/O Terminals\u003c\/td\u003e\n\u003ctd\u003e16 spring-clamp points\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCommon Terminals\u003c\/td\u003e\n\u003ctd\u003e18 spring-clamp points\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eVoltage Terminals\u003c\/td\u003e\n\u003ctd\u003e18 spring-clamp points (+V)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEnclosure Type\u003c\/td\u003e\n\u003ctd\u003eIP20 open style\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMounting Base\u003c\/td\u003e\n\u003ctd\u003e35 mm symmetric DIN rail\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/figure\u003e\n\u003ch3\u003eBus Communication and Wiring Layout\u003c\/h3\u003e\n\u003cp\u003eThe terminal base manages internal backplane bus communication velocity across adjacent active processing hardware, preventing local register drop-outs over EtherNet\/IP deterministic networks. The integrated spring-clamp termination geometry expands I\/O density scaling by offering 16 individual signal terminations, 18 common links, and 18 positive voltage source connection slots in a single open-style footprint. This internal routing layout eliminates external distribution blocks, ensuring direct field-side termination paths. Mechanical alignment tolerances guarantee long-term hardware configuration stability and complete firmware compatibility when matching analog or digital logic components are attached to the block.\u003c\/p\u003e\n\u003ch3\u003eBox Packing Elements\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e1 x 1794-TB3S FLEX I\/O Spring-Clamp Terminal Base\u003c\/li\u003e\n\u003cli\u003e1 x FlexBus sliding interface connector piece\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eField Installation Guidelines\u003c\/h3\u003e\n\u003ch3\u003eWiring Constraints\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eDepress the cage clamp mechanism fully using a standard slot screwdriver tool before feeding in stripped conductors.\u003c\/li\u003e\n\u003cli\u003eStrip field wire outer insulation layers to 10 mm to ensure proper spring compression engagement inside the slot.\u003c\/li\u003e\n\u003cli\u003eDo not combine solid and stranded copper lines within a single spring-clamp landing port.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eGrounding Rules\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eSnap the module housing firmly onto a clean, unpainted steel 35 mm DIN rail to establish a dedicated chassis ground path.\u003c\/li\u003e\n\u003cli\u003eVerify the spring-loaded grounding clip on the back of the base makes continuous bare-metal contact with the mounting track.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eShielding Requirements\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eTerminate analog field loop shields at an isolated instrument ground bus located outside the local termination block.\u003c\/li\u003e\n\u003cli\u003eDo not connect shield drain wires to the internal common or voltage terminals of the base assembly.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eBackplane Insertion Rules\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eSlide the left-side FlexBus connector completely into the preceding unit before locking the terminal base down.\u003c\/li\u003e\n\u003cli\u003eEnsure all mating pins are aligned straight before pressing an active module onto the terminal base top seat.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eEnvironmental Limitations\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eMount the IP20 open-style block within a NEMA or IP-rated enclosure to prevent particulate accumulation on contact surfaces.\u003c\/li\u003e\n\u003cli\u003eMaintain a 25 mm air clearance perimeter around the base unit to permit natural convective cooling under high current loads.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eTechnical Support FAQ\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003eQ: What is the hot-swap behavior when replacing an active I\/O module positioned on this terminal base?\u003c\/p\u003e\n\u003cp\u003eA: The base unit sustains continuous backplane bus communication across adjacent nodes, permitting live hot-swap replacement of the upper module without dropping system network nodes.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eQ: What is the backplane load contribution of the terminal base when added to a FlexBus segment?\u003c\/p\u003e\n\u003cp\u003eA: The hardware consists of passive conductor traces and spring contacts, drawing 0 mA of electrical current from the control backplane logic supply.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eQ: What redundancy switching delay is added by this component during a processor switchover?\u003c\/p\u003e\n\u003cp\u003eA: As a passive structural interconnection device with no internal registers or memory, it introduces a 0 ms delay during system redundancy switching operations.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eQ: Are there firmware compatibility limitations when using this base revision with legacy series modules?\u003c\/p\u003e\n\u003cp\u003eA: No, the unit is entirely hardware-based and analog, which eliminates dependencies on firmware flash levels, software builds, or electronic microcode versions.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eQ: How does the internal signal isolation mechanism separate field loops from the logical backplane?\u003c\/p\u003e\n\u003cp\u003eA: The base provides passive copper trace paths; all channel-to-channel or galvanic backplane isolation operations are handled inside the active plugged module.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eQ: What specific field wiring constraints govern the selection of wires for these spring-clamp blocks?\u003c\/p\u003e\n\u003cp\u003eA: Use solid or stranded copper wire sized between 0.34 mm2 (22 AWG) and 2.1 mm2 (14 AWG) rated for the target loop operating voltage.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eQ: Can this base handle simultaneous combinations of AC and DC loop voltages across separate channels?\u003c\/p\u003e\n\u003cp\u003eA: The base insulation holds up to 125 VAC\/DC, but the actual voltage configuration must match the specific limits of the single module installed.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eQ: What causes potential intermittent connection issues inside a spring-clamp terminal slot?\u003c\/p\u003e\n\u003cp\u003eA: Intermittent contact typically stems from under-stripping wire insulation or leaving wire strands bent outside the internal compression cage during tool execution.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":46066459508909,"sku":"1794-TB3S","price":159.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0733\/1613\/9181\/files\/1794-TB3S_133.jpg?v=1784024964","url":"https:\/\/www.maxwellplc.com\/ga\/products\/1794-tb3s-allen-bradley-flex-i-o-series-terminal-base-unit","provider":"Maxwell PLC Ltd","version":"1.0","type":"link"}