Safety Over Ethernet Options Increasing

With the idea of using a shared real-time Ethernet network for machine control and safety quickly gaining acceptance, suppliers and technology organizations are scrambling to make this integrated safety strategy easier to implement. The latest development on that score comes from SERCOS International and Germany’s IXXAT Automation GmbH.

IXXAT will this year develop a new software stack for the “CIP Safety on SERCOS” protocol. Consisting of a CIP Safety layer and a CIP Safety on SERCOS adaptation layer, the new software stack will be designed for both SERCOS master and slave implementations.

CIP Safety On Sercos isn’t a brand new concept, but IXXAT’s involvement will help standardize it. According to Ron Larsen, managing director of SERCOS North America,  CIP Safety on SERCOS previously required individual implementations by the various drive and control vendors. “The whole idea with IXXAT is to have a standardized solution that keeps everyone from having to reinvent the wheel,”  Larsen says.

He adds that software will be pre-certified to IEC 61508 SIL 3 by TÜV and BGIA, two key European safety agencies.

In a related move, IXXAT will also develop a SERCOS III interface module based on its Universal Industrial Ethernet Module.  By putting the full SERCOS III real-time Ethernet functionality onto an Altera FPGA, IXXAT’s module allows a wide variety of slave devices to connect to a host system via a universal interface. Similar modules for other varieties of real-time Ethernet have already been developed.

IXXAT, a specialist in data communications technologies for automotive and industrial automation, is no newcomer to the safety arena. The company has already helped develop similar safety software for Ethernet Powerlink. “We already have the certified safety engineers on staff to develop safety applications,” say Bill Seitz, president of IXXAT North America.

On the hardware side, IXXAT will make good use of its experience developing Ethernet technologies on FPGAs. These include not only the industrial Ethernet modules for slave devices–such as the forthcoming module for SERCOS III–but also FPGA-based controllers for safety. “Developing safety solutions on FPGAs gives us the flexibility we need to adapt to all the different kinds of industrial Ethernet,” says Seitz.