Today, machines, plants and safety systems are stuck in a rigid scheme made up of hardware-based safety functions. The consequences of this are cost-intensive cabling and limited diagnostic options. More recent attempts with safety field buses are characterized by proprietary standard and limited cycle times in the millisecond range. These buses will soon be obsolete due to the rapid deployment of Real-Time Industrial Ethernet. A thorough analysis of existing safety protocols has shown that these are not suitable to be integrated within an open Real-Time Ethernet network.
Therefore the EPSG has defined the next generation safety protocol for Real-Time Industrial Ethernet: Ethernet Powerlik Safety (EPLsafety). EPLsafety allows both publish/subscriber and client/server communication. Safety relevant data is transmitted via an embedded data frame inside of standard communication messages. Measures to avoid any undetected failures due to systematic or stochastic errors are an integral part of the safety protocol. EPLsafety is in conformance with IEC 61508.
The protocol fulfills the requirements of SIL3, and within specific architectures also SIL 4. Error detection techniques have no impact on existing transport layers.
EPLsafety Highlights:
• Real-Time Industrial Ethernet compliant• Data transfer time as low as 100µs• Conform to international safety standard IEC 61508• Fulfills requirements of Safety Integrity Level 3 (SIL 3, IEC 61508)• SIL 4 achieved with specific architectures• Standard and safety related devices are using the same communication network• Compatible with CANopen• Supports hierarchical mixed Ethernet and field bus systems• Routable via standard (non safety related) gateways• Independent of transport media• Up to 4096 safety related devices within 1 safety domain• Up to 4096 safety domains• Fully compatible with Ethernet TCP/IPFor more information visit www.br-automation.com .
