Single Wire Coexistence of Sercos and EtherNet/IP

Technical Abstract

Request for standardized high level functionality (e.g., functional safety) has led to the use of the CIP Safety protocol on sercos. CIP Safety enables vendors to reuse their development efforts and users to rely on widely supported standards.

Rexroth is now developing a solution that allows EtherNet/IP and sercos devices to be operated over a single Ethernet cable. The controller will contain a combined sercos master and EtherNet/IP Scanner which allow devices of both networks to be combined in system applications.

For proof of concept several configurations have been investigated in terms of

  • Topology
  • Stability
  • Features
    • Real Time for both sercos and EtherNet/IP
    • CIP Safety devices on both networks
    • No limits in connection size, except channel bandwidth
    • All standard IP frames supported
    • Limits due to bandwidth and timing detected during engineering phase
  • Conformance to Ethernet physical layer, common rules for cabling

The concept was successfully verified. Detected limits will be removed in the next release of the Sercos specification.

Paper and presentation from the 2012 ODVA Industry Conference & 15th Annual Meeting

Ludwig Leurs, Bosch Rexroth AG