{"product_id":"allen-bradley-1756-a7-b-controllogix-chassis-module","title":"Allen-Bradley 1756-A7\/B ControlLogix Chassis Module","description":"\u003ch1 class=\"PDq2pG_selectionAnchorContainer\"\u003eAllen-Bradley 1756-A7\/B ControlLogix Chassis Module\u003cspan class=\"PDq2pG_selectionAnchor\"\u003e\u003c\/span\u003e\n\u003c\/h1\u003e\n\u003cp\u003eThe\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eAllen-Bradley 1756-A7\/B\u003c\/strong\u003e, also cataloged as the\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e1756-A7\/B ControlLogix Chassis\u003c\/strong\u003e, serves as the primary\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eControlLogix backplane chassis\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eutilized to execute module slot hosting and distributed backplane power routing across ControlLogix platforms. The chassis provides physical slot interconnect and electrical bus alignment for installed I\/O, CPU, and communication modules within a 7-slot configuration.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003eSuffix Breakdown \u0026amp; Model Matrix\u003c\/h3\u003e\n\u003cp\u003eNo formal suffix segmentation is defined for the 1756-A7\/B chassis structure.\u003c\/p\u003e\n\u003cul class=\"list-paddingleft-2\"\u003e\n\u003cli\u003e\n\u003cp\u003e1756-A7\/B: ControlLogix chassis platform, 7-slot backplane architecture, Series B mechanical revision\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003eHardware Specifications\u003c\/h3\u003e\n\u003ctable class=\"w-fit min-w-(--thread-content-width)\"\u003e\n\u003cthead\u003e\n\u003ctr class=\"firstRow\"\u003e\n\u003cth class=\"last:pe-10\"\u003eParameter\u003c\/th\u003e\n\u003cth class=\"last:pe-10\"\u003eSpecification\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\u003e1756-A7\/B\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\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e1.10 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions\u003c\/td\u003e\n\u003ctd\u003e50.8 cm x 60.9 cm x 20.3 cm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower Consumption\u003c\/td\u003e\n\u003ctd\u003eMax power dissipation 4.5 W\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSlots\u003c\/td\u003e\n\u003ctd\u003e7\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBackplane Voltage (1.2 V DC)\u003c\/td\u003e\n\u003ctd\u003e1.5 A chassis current\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBackplane Voltage (3.3 V DC)\u003c\/td\u003e\n\u003ctd\u003e4 A chassis \/ 4 A per slot\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBackplane Voltage (5.1 V DC)\u003c\/td\u003e\n\u003ctd\u003e15 A chassis \/ 6 A per slot\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBackplane Voltage (24 V DC)\u003c\/td\u003e\n\u003ctd\u003e2.8 A chassis \/ 2.8 A per slot\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMounting\u003c\/td\u003e\n\u003ctd\u003eHorizontal panel mount only\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eEnclosure Rating\u003c\/td\u003e\n\u003ctd\u003eNone (open chassis design)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGrounding\u003c\/td\u003e\n\u003ctd\u003eFunctional earth 8 AWG, protective earth 14 AWG\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003chr\u003e\n\u003ch3\u003eBackplane Communication and Power Distribution Architecture (ControlLogix System Bus Behavior)\u003c\/h3\u003e\n\u003cp\u003eThe 1756-A7\/B implements a high-speed multi-voltage backplane structure supporting synchronized power distribution across 1.2 V DC, 3.3 V DC, 5.1 V DC, and 24 V DC rails. Each slot is electrically coupled through a shared backplane bus, enabling deterministic module-to-module communication latency governed by ControlLogix internal arbitration logic.\u003c\/p\u003e\n\u003cp\u003eBackplane current allocation is segmented per voltage domain, with per-slot current ceilings defined to prevent bus saturation during high-density I\/O or processor load conditions. The chassis does not perform signal processing but enforces electrical continuity and bus impedance matching for installed modules.\u003c\/p\u003e\n\u003cp\u003eSignal integrity across the backplane is dependent on module firmware compatibility and chassis revision level (Series B mechanical baseline). Grounding architecture separates functional earth and protective earth to stabilize reference potential across distributed modules, reducing common-mode voltage drift in mixed analog\/digital configurations.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003eFrequently Asked Questions (FAQ)\u003c\/h3\u003e\n\u003cp\u003eQ: Does the 1756-A7\/B support hot-swap module insertion?\u003cbr\u003eA: Yes. ControlLogix architecture supports module hot-swap depending on installed module type and system configuration. Backplane remains energized during controlled insertion\/removal cycles.\u003c\/p\u003e\n\u003cp\u003eQ: What limits backplane current distribution across slots?\u003cbr\u003eA: Current is limited by internal backplane rail segmentation per voltage domain (1.2 V, 3.3 V, 5.1 V, 24 V DC). Each slot has defined current ceilings enforced by chassis backplane design.\u003c\/p\u003e\n\u003cp\u003eQ: Is electrical isolation provided between slots?\u003cbr\u003eA: Isolation is not implemented at chassis level. Channel-to-channel or module isolation is determined by installed module design, not by the 1756-A7\/B chassis.\u003c\/p\u003e\n\u003chr\u003e\u003chr\u003e\n\u003ch3\u003eField Installation Guidelines\u003c\/h3\u003e\n\u003cul class=\"list-paddingleft-2\"\u003e\n\u003cli\u003e\n\u003cp\u003eInstall chassis in horizontal orientation only to maintain designed backplane connector alignment.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eEnsure cabinet structural rigidity to prevent mechanical stress on backplane connectors during module insertion.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eMaintain proper grounding using specified functional earth and protective earth conductors before energizing system.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eRoute power and communication cabling separately to reduce electromagnetic coupling into backplane reference plane.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eVerify minimum clearance above and below chassis to support convection airflow across installed modules.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eAvoid partial module insertion under energized conditions unless module type explicitly supports hot-swap operation.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":43572349337690,"sku":"1756-A7\/B","price":123.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0612\/4601\/3530\/files\/1756-A71.jpg?v=1778667100","url":"https:\/\/www.plcmasters.com\/products\/allen-bradley-1756-a7-b-controllogix-chassis-module","provider":"PLC Masters Ltd.","version":"1.0","type":"link"}