{"product_id":"beckhoff-el1904-ethercat-twinsafe-digital-input-terminal","title":"BECKHOFF EL1904 Bornier d'entrée numérique TwinSAFE EtherCAT","description":"\u003ch3\u003eProduct Overview\u003c\/h3\u003e\n\u003cp\u003eThe\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eEL1904 (EL1904)\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eis a specialized EtherCAT Terminal designed for functional safety within the Beckhoff TwinSAFE ecosystem. This 4-channel digital input terminal allows for the direct connection of safety-related sensors, such as emergency stop buttons, light curtains, and safety switches, to the EtherCAT I\/O system. Operating at 24 VDC, the\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eEL1904\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003efulfills the most stringent safety requirements by utilizing the\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eSafety over EtherCAT (FSoE)\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eprotocol, enabling seamless integration of safety and standard automation data on the same network. By decentralizing safety logic and providing high-density monitoring in a compact 12 mm housing, this module is critical for reducing wiring overhead in complex manufacturing cells, power plants, and automated assembly lines while ensuring SIL 3\/Category 4 protection levels.\u003c\/p\u003e\n\u003ch3\u003eTechnical Configuration (Deep Dive)\u003c\/h3\u003e\n\u003cp\u003eThe EL1904 architecture is built around the TwinSAFE protocol, which ensures data integrity through diverse signal processing.\u003c\/p\u003e\n\u003cul class=\"list-paddingleft-2\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eTwinSAFE\/FSoE Protocol:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eThe terminal communicates via the Safety over EtherCAT protocol, where safety-related data is encapsulated within standard EtherCAT frames. This \"black channel\" approach allows for safety communication across any standard network media without compromising the safety function.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eSafety Logic Integration:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eEach of the four channels features a parameterizable input filter. The module performs internal cross-checking of the input signals and the FSoE communication. If a fault is detected (e.g., a communication timeout or internal hardware failure), the terminal enters a \"Safe State\" within the defined fault response time, typically governed by the watchdog timer settings.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eWiring Versatility:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eSupporting both 1-wire and 2-wire connection technologies, the terminal provides flexibility for various sensor types. The tension clamp system allows for rapid wiring of solid or stranded conductors, ensuring vibration-proof connections in harsh industrial environments.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr class=\"firstRow\"\u003e\n\u003ctd\u003e\u003cstrong\u003eParameter\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cstrong\u003eSpecification Details\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eModel\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eEL1904\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eBrand\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eBECKHOFF\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eOrigin\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eGermany\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eNumber of Inputs\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e4 Safety Digital Inputs\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eConnection Type\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e1-\/2-wire technology\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eProtocol\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eTwinSAFE \/ Safety over EtherCAT (FSoE)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eResponse Time\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eTyp. 4 ms (read input\/write to E-bus)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eCurrent Consumption\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eTyp. 200 mA (E-bus)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eDimensions\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e100 mm x 12 mm x 68 mm\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eWeight\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e0.05 kg (Shipping weight 2 kg)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eHousing Material\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003ePolycarbonate\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eMounting\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e35 mm DIN rail (EN 60715)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003e\u003cstrong\u003eProtection Rating\u003c\/strong\u003e\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eIP20\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eTechnical FAQs\u003c\/h3\u003e\n\u003cul class=\"list-paddingleft-2\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is the \"Watchdog Time\" and how does it affect the fault response?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe watchdog time is a parameterizable safety timing window. If the EL1904 does not receive a valid FSoE frame within this period, it automatically triggers a fault response and moves to a safe state. This ensures that a loss of communication is handled with the same priority as a physical emergency stop trigger.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eCan the EL1904 be used without a TwinSAFE Logic terminal?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eNo. The EL1904 functions as a safety \"alias\" device. It requires a TwinSAFE Logic terminal (such as an EL6910 or an integrated Safety PLC) to process the safety signals and execute the programmed safety logic.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is the maximum current load for the power contacts?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe EL1904 is rated for a maximum current load of 10 A through the power contacts. It is essential to calculate the total current draw of all downstream terminals in the segment to ensure this limit is not exceeded.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch3\u003eEngineering \u0026amp; Installation Guide\u003c\/h3\u003e\n\u003cul class=\"list-paddingleft-2\"\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eSpring-Clamp Termination:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eFor optimal reliability, strip conductors to exactly 8-9 mm. When using flexible stranded wire, the use of ferrules is recommended (0.14 to 1.5 mm²) to prevent fraying and potential short circuits between the high-density terminal points.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eHorizontal Thermal Management:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eThe EL1904 is designed for horizontal installation on a 35 mm DIN rail. Ensure that the double slot and key connection is firmly engaged with adjacent terminals to maintain the integrity of the E-bus and power contacts. Maintain adequate clearance above and below the terminal row for natural convection cooling.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003eShielding for Safety Integrity:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eTo prevent nuisance tripping from electromagnetic interference, ensure that all safety sensor cables are properly routed away from high-voltage motor leads. For long cable runs, utilize shielded cables grounded at the entry point of the control cabinet.\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eEngineering Advantages\u003c\/h3\u003e\n\u003cp\u003eThe\u003cspan\u003e \u003c\/span\u003e\u003cstrong\u003eEL1904\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003estands out for its extreme reliability in high-vibration environments, characterized by its robust polycarbonate housing and spring-actuated wiring. Its primary advantage lies in \"Safety-at-the-Point-of-Use\"—by placing safety inputs directly on the EtherCAT segment, engineers eliminate the need for long, expensive home-run wiring to a central safety relay. This modularity allows for rapid machine expansion; adding another safety zone is as simple as clipping an EL1904 onto the DIN rail and updating the TwinSAFE logic configuration.\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"BECKHOFF","offers":[{"title":"Default Title","offer_id":53106708185451,"sku":"EL1904","price":100.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0953\/3227\/0443\/files\/el1904-zjd02puim5f.png?v=1776244392","url":"https:\/\/www.plcprotech.com\/fr\/products\/beckhoff-el1904-ethercat-twinsafe-digital-input-terminal","provider":"PLC ProTech Ltd.","version":"1.0","type":"link"}