{"product_id":"allen-bradley-1756-srm-redundancy-module","title":"Allen Bradley 1756-SRM Redundancy Module","description":"\u003ch1\u003eAllen-Bradley 1756-SRM ControlLogix System Redundancy Module\u003c\/h1\u003e\n\u003cp\u003eThe \u003cstrong\u003eAllen-Bradley 1756-SRM\u003c\/strong\u003e is a ControlLogix System Redundancy Module used to synchronize primary and secondary ControlLogix controllers in redundant automation architectures. Installed as a matched pair across redundant chassis, the module manages redundancy communications through dedicated fiber-optic links, enabling automatic switchover between controllers while maintaining identical hardware configurations.\u003c\/p\u003e\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003ctable class=\"___1vyiefv f1ddd56o f16vktn6 f1ahpp82 f11qra4b f1uinfot fibjyge fvueend f9yszdx f1fu4s3n f3l3pb3 f10ghnd0 f8fmt76 fjvbh62 f1qrqxae f1vw5qpk fc02sbz fxawf59 fymf513 f1aoyrul f1el8yx3 f1pymoxg f1ofu761 fe6itr f7coize f1794535 f1o0pw0q fbjjl9v fk1v6el f16pyhcb f1ixlhx9 f12zef0i flu5r5u f19haqzy f1owmcxx f1oddm8q f1004tna fcoaxci fh0ee9u f15v23i2 f1dmj53 f1r1gcv9 f14z1veh ffufd3x f1ypplot f1660cg\"\u003e\n\u003ctbody\u003e\n\u003ctr class=\"firstRow\"\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003e1756-SRM\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\u003eProduct Type\u003c\/td\u003e\n\u003ctd\u003eSystem Redundancy Module\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eChassis Slots Required\u003c\/td\u003e\n\u003ctd\u003e2 slots\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCommunication Media\u003c\/td\u003e\n\u003ctd\u003eDuplex fiber-optic cable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompatible Fiber Cables\u003c\/td\u003e\n\u003ctd\u003e1757-SRC series\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAvailable Cable Lengths\u003c\/td\u003e\n\u003ctd\u003e1 m, 3 m, 10 m, 50 m, 100 m\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower Source\u003c\/td\u003e\n\u003ctd\u003eControlLogix chassis backplane\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eIntegrated Features\u003c\/td\u003e\n\u003ctd\u003ePrimary status relay, fiber-optic ports\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Temperature\u003c\/td\u003e\n\u003ctd\u003e0 deg C to 60 deg C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eShipping Weight\u003c\/td\u003e\n\u003ctd\u003eApprox. 2 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eRedundant Controller Architecture\u003c\/h3\u003e\n\u003cp\u003eThe 1756-SRM is designed for ControlLogix redundant control systems that use a primary chassis and a synchronized secondary chassis. Each chassis requires an identical redundancy module installation and matching slot assignments to maintain synchronization.\u003c\/p\u003e\n\u003cp\u003eThe module continuously exchanges controller and system status information between the redundant chassis. If the primary controller becomes unavailable, the redundant system can transfer control to the secondary chassis according to the configured redundancy strategy.\u003c\/p\u003e\n\u003ch3\u003eFiber-Optic Synchronization\u003c\/h3\u003e\n\u003cp\u003eCommunication between redundancy modules is established through duplex fiber-optic connections. The module uses dedicated 1757-SRC series redundancy cables available in multiple lengths, allowing physical separation between primary and secondary systems while maintaining high-speed synchronization.\u003c\/p\u003e\n\u003cp\u003eThe integrated fiber-optic ports are dedicated to redundancy communication and are separate from standard ControlLogix network communications.\u003c\/p\u003e\n\u003ch3\u003eSupported ControlLogix Platforms\u003c\/h3\u003e\n\u003cp\u003eThe 1756-SRM is intended for legacy ControlLogix redundancy systems using compatible controllers and communication modules.\u003c\/p\u003e\n\u003cp\u003eConfirmed compatible controllers include:\u003c\/p\u003e\n\u003cul class=\"list-paddingleft-2\"\u003e\n\u003cli\u003e\n\u003cp\u003eControlLogix5555 (1756-L55 series)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eControlLogix5560 (1756-L61, 1756-L62, 1756-L63)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eSupported network modules include:\u003c\/p\u003e\n\u003cul class=\"list-paddingleft-2\"\u003e\n\u003cli\u003e\n\u003cp\u003e1756-ENBT EtherNet\/IP bridge\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e1756-CNB ControlNet bridge\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e1756-CNBR Redundant ControlNet bridge\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eCompatibility should always be verified against the installed controller firmware, redundancy revision, and system architecture before replacement or expansion.\u003c\/p\u003e\n\u003ch3\u003eSystem Design Requirements\u003c\/h3\u003e\n\u003cp\u003eA key design requirement of the 1756-SRM redundancy architecture is that the primary and secondary chassis must use identical slot configurations. In addition, local I\/O modules are not permitted within the synchronized redundant chassis structure.\u003c\/p\u003e\n\u003cp\u003eInstead, field signals are transferred through remote I\/O networks, allowing both redundant controllers to maintain a consistent view of system operation while supporting deterministic redundancy behavior.\u003c\/p\u003e\n\u003ch3\u003eHardware Integration\u003c\/h3\u003e\n\u003cp\u003eThe module draws operating power directly from the ControlLogix chassis backplane and does not require a separate external power source. A built-in primary status relay provides an additional method for external indication of redundancy state and controller ownership.\u003c\/p\u003e\n\u003cp\u003eBecause redundancy performance depends on both chassis remaining synchronized, hardware replacement should be performed using matching module revisions and approved redundancy components.\u003c\/p\u003e\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eQ: How many chassis slots does the 1756-SRM require?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA: The module occupies two chassis slots. The slot arrangement must be identical in both the primary and secondary redundant chassis.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: What communication method is used between redundant systems?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA: The module uses duplex fiber-optic communication through dedicated 1757-SRC redundancy cables available in lengths from 1 m to 100 m.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Can local I\/O modules be installed in a 1756-SRM redundant chassis?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA: No. The documented redundancy architecture requires system I\/O to be implemented through remote I\/O networks rather than local chassis I\/O modules.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eQ: Which ControlLogix controllers are supported?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA: Confirmed compatible processors include the ControlLogix5555 (1756-L55 series) and ControlLogix5560 controllers including 1756-L61, 1756-L62, and 1756-L63 models.\u003c\/p\u003e","brand":"Allen-Bradley","offers":[{"title":"Default Title","offer_id":67760524329034,"sku":"1756-SRM","price":530.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0587\/8569\/3770\/files\/1756-IF16_3.png?v=1768552371","url":"https:\/\/www.topbrandsplc.com\/products\/allen-bradley-1756-srm-redundancy-module","provider":"Topbrands PLC Limited","version":"1.0","type":"link"}