EL1904 | Beckhoff EtherCAT TwinSAFE 4-Channel Safe Digital Input Terminal

Description 

The Beckhoff EL1904 is a TwinSAFE EtherCAT input terminal designed for safety-related signal acquisition from potential-free 24 V DC contacts. It provides four independent fail-safe input channels and delivers safety-relevant data to a TwinSAFE logic component via FSoE communication.

Technical Specifications 

Information About EL1904

The EL1904 is a TwinSAFE EtherCAT digital input terminal designed for acquiring safety-relevant 24 V DC signals through four fail-safe channels, transmitting them to a TwinSAFE Logic component via Fail Safe over EtherCAT (FSoE). It supports configurable safety parameters such as 1- or 2-channel evaluation, individual channel testing, and cross-circuit detection, ensuring flexibility for various safety architectures. Because parameters are stored in the logic controller rather than the terminal, replacement is simplified—installing a new terminal automatically restores all safety settings upon application start. Engineered to meet SIL 3 and PL e safety requirements, the EL1904 provides dependable, high-integrity safety integration for modern EtherCAT systems.

Key Features:

• Four Independent Fail-Safe Inputs: Supports potential-free 24 V DC sensors such as emergency stop switches, interlocks, and safety contacts with high reliability.
• TwinSAFE FSoE Communication: Ensures secure, deterministic safety data transfer directly to TwinSAFE Logic components for real-time evaluation.
• Flexible Safety Evaluation: Allows per-channel configuration for 1-channel or 2-channel redundancy, enabling adaptation to various safety designs and required PL/SIL levels.
• Cross-Circuit and Wiring Fault Detection: Automatically identifies short circuits, open circuits, and unintended cross-connections to prevent unsafe states.
• Software-Stored Safety Parameters: Parameters reside in the logic device, not the terminal, enabling plug-and-play replacement without reconfiguration.
• Individual Channel Test Functions: Enables activation of test pulses for each input, improving diagnostic coverage and compliance with high safety categories.
• Fast Response Time: Typical 4 ms input-to-bus processing ensures rapid reaction to safety events in time-critical applications.
• Certified for High Safety Standards: Meets SIL 3 (EN 61508) and PL e Category 4 (EN ISO 13849-1), supporting demanding machine safety requirements.
• Compact EtherCAT Terminal Design: Offers high channel density and seamless cabinet integration while maintaining electrical isolation and robust performance.

The EL1904 delivers the reliability, diagnostics, and functional safety depth required for advanced EtherCAT-based safety architectures.