SERCOS III

SERCOS III

Sercos III is the third generation of the sercos interface, a globally standardized open digital interface for the communication between industrial controls, motion devices, and input/output devices (I/O). Sercos III merges the hard real-time aspects of the sercos interface with Ethernet. It is based upon and conforms to the Ethernet standard (IEEE 802.3 & ISO/IEC 8802-3). Work began on sercos III in 2003, with vendors releasing first products supporting it in 2005. In addition to the standard sercos features cited under the sercos interface general description, sercos III also provides:

• Cyclic updates to devices at rates as low as 31.25 µs
• Support for up to 511 Slave devices on one network
• Redundancy: Bump-less physical layer single-fault recovery
• Detection of a dropped physical connection within 25 µs (less than one cycle update)
• Hot plugging: insertion & configuration of devices into network while cyclic communication is active.
• Peer-to-peer communications: both controller-to-controller (C2C) for multiple masters to communicate with one another and direct cross-communication (CC) among multiple slave devices.