{"product_id":"allen-bradley-1756-dhrio-communication-module","title":"Allen Bradley 1756-DHRIO Communication Module","description":"\u003ch1 class=\"PDq2pG_selectionAnchorContainer\"\u003eAllen Bradley 1756-DHRIO Communication 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-DHRIO\u003c\/strong\u003e, also cataloged as the\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003e1756-DHRIO\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eCommunication Module, operates as a dedicated hardware component for Data Highway Plus bridging and Remote I\/O scanning within ControlLogix backplane architectures.\u003c\/p\u003e\n\u003cp\u003eConfigured for dual-network communication routing in ControlLogix chassis systems, the\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eAllen Bradley 1756-DHRIO\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003e(\u003cstrong\u003e1756-DHRIO\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eCommunication Module) provides direct physical\/electrical execution of DH+ messaging and RIO scan control across two independent communication channels.\u003c\/p\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-DHRIO\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\u003e0.28 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower Consumption\u003c\/td\u003e\n\u003ctd\u003e24 VDC backplane, up to 850 mA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNumber of Channels\u003c\/td\u003e\n\u003ctd\u003e2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eNetwork Types\u003c\/td\u003e\n\u003ctd\u003eData Highway Plus \/ Remote I\/O\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCommunication Rates\u003c\/td\u003e\n\u003ctd\u003e57.6 \/ 115.2 \/ 230.4 Kbps\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDH+ Message Capacity\u003c\/td\u003e\n\u003ctd\u003e32 messages per module\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRIO Connections\u003c\/td\u003e\n\u003ctd\u003e32 per channel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBlock Transfer Connections\u003c\/td\u003e\n\u003ctd\u003e16 per channel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eBackplane Bus Communication Velocity and EtherNet\/IP Deterministic Network Coordination (ControlLogix DH+ \/ RIO Layer)\u003c\/h3\u003e\n\u003cp\u003eThe 1756-DHRIO module executes protocol translation between ControlLogix backplane scan cycles and legacy DH+ \/ RIO serial architectures. Channel separation maintains independent timing domains for DH+ messaging and Remote I\/O scanning.\u003c\/p\u003e\n\u003cp\u003eBackplane transaction throughput is constrained by scheduled task execution within ControlLogix controllers. Each channel operates with fixed baud rate selection and deterministic polling intervals defined by network configuration switches.\u003c\/p\u003e\n\u003cp\u003eRIO scan logic maintains fixed rack connection mapping, supporting up to 32 RIO connections per channel with deterministic block transfer sequencing.\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions (FAQ)\u003c\/h3\u003e\n\u003cp\u003eQ: Can the 1756-DHRIO module be hot-swapped in an energized ControlLogix chassis?\u003cbr\u003eA: Hot-swap is supported only under ControlLogix chassis rules. Network sessions are reset during module reinsertion and require reestablishment of DH+ and RIO links.\u003c\/p\u003e\n\u003cp\u003eQ: What limits the maximum communication throughput on DH+ networks?\u003cbr\u003eA: Throughput is constrained by selectable baud rate (57.6 \/ 115.2 \/ 230.4 Kbps) and message arbitration across shared DH+ bus access.\u003c\/p\u003e\n\u003cp\u003eQ: Does each channel operate independently?\u003cbr\u003eA: Yes. Each of the two channels maintains independent DH+ or RIO communication stacks with separate configuration parameters.\u003c\/p\u003e\n\u003chr\u003e\n\u003ch3\u003eField Installation Guidelines\u003c\/h3\u003e\n\u003cp\u003eInsert the 1756-DHRIO module into a powered-down or chassis-supported hot-insert slot according to ControlLogix mechanical alignment rails. Ensure full backplane connector engagement before applying system power.\u003c\/p\u003e\n\u003cp\u003eMaintain proper separation between DH+ cabling and high-noise power conductors to reduce induced coupling on serial communication lines. Use shielded twisted pair for DH+ and ensure single-point grounding of the shield.\u003c\/p\u003e\n\u003cp\u003eVerify rotary or switch-based network configuration settings prior to system startup. Incorrect baud rate selection will prevent network synchronization across DH+ or RIO segments.\u003c\/p\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":43581167337562,"sku":"1756-DHRIO","price":123.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0612\/4601\/3530\/files\/1756-DHRIO2.jpg?v=1782963720","url":"https:\/\/www.plcmasters.com\/products\/allen-bradley-1756-dhrio-communication-module","provider":"PLC Masters Ltd.","version":"1.0","type":"link"}