BECKHOFF EL1904 - Manual (Page 12)

System description
10 EL1904
2.2 TwinSAFE
2.2.1 The I/O construction kit is extended safely
With the TwinSAFE Terminals, Beckhoff offers the option of simply expanding the proven Bus Terminal
system, and to transfer the complete cabling for the safety circuit into the already existing fieldbus cable.
Safe signals can be mixed with standard signals without restriction. This saves design effort, installation
and material. Maintenance is simplified significantly through faster diagnosis and simple replacement of
only a few components.
The new ELx9xx series Bus Terminals only include three basic functionalities: digital inputs EL19xx,
digital outputs EL29xx and a logic unit EL6900. For a large number of applications, all sensors and
actuators can be wired on these Bus Terminals. The required logical link of the inputs and the outputs is
handled by the EL6900. For small to medium-sized configurations, the tasks of a fail-safe PLC can thus
be handled within the Bus Terminal system.
2.2.2 Safety concept
TwinSAFE: Safety and I/O technology in one system
 Extension of the familiar Beckhoff I/O system with TwinSAFE terminals
 Freely selectable mix of safe and standard signals
 Logical link of the I/Os in the EL6900 TwinSAFE logic terminal
 Safety-relevant networking of machines via bus systems
TwinSAFE protocol (Fail Safe over EtherCAT - FSoE)
 Transfer of safety-relevant data via any media (“genuine black channel”)
 TwinSAFE communication via fieldbus systems such as EtherCAT, Lightbus, PROFIBUS or
Ethernet
 IEC 61508:2010 SIL 3 compliant
Configuring instead of wiring: the TwinSAFE configurator
 Configuration of the TwinSAFE system via the TwinCAT System Manager
 System Manager for editing and displaying all bus parameters
 Certified function blocks such as emergency stop, operation mode, etc.
 Simple handling
 Typical function blocks for machine safety
 Any bus connection with the EL6900 TwinSAFE logic terminal
TwinSAFE logic Bus Terminal EL6900
 Link unit between TwinSAFE input and output terminals
 Configuration of a simple, flexible, cost-effective, decentralized safety controller
 No safety requirements for higher-level control system
 TwinSAFE enables networks with up to 65535 TwinSAFE devices
 TwinSAFE logic terminal can establish up to 128 connections (TwinSAFE connections).
 Several TwinSAFE logic terminals are cascadable in a network
 Safety functions such as emergency stop, protective door etc. are already included
 Suitable for applications up to SIL 3 according to IEC 61508:2010 and DIN EN ISO 13849-
1:2006 (Cat 4, PL e).