Citing what it called “an important milestone,” the EtherCat Technology Group (ETG, www.ethercat.org) announced on July 13 that the Safety-over-EtherCat Protocol has been accepted unanimously by the 27 national committees of the International Electrotechnical Commission (IEC), together with the IEC 67184-3 specification. The IEC approval will further leverage the wide acceptance and uniform use of EtherCat technology within the automation world, the ETG said.
The Safety-over-EtherCat protocol is referred to as FSCP 12 (Functional Safety Communication Profile) in the IEC 61784-3 specification. This standard defines the fundamental requirements of a communication system in terms of safety relevant data transmission. In order to do so, it also defines potential errors whose occurrences have to be assumed and describes possible recognition and corrective measures. All requirements are met safely by the Safety-over-EtherCat Protocol.
The Safety-over-EtherCat protocol was introduced by the ETG and has been used in applications worldwide since 2005, the organization said. The protocol is well-suited for applications up to the Safety Integrity Level 3 (SIL 3) according to IEC 61508. Safety communication and standard communication use a single bus system.
Black channel
Use of Safety-over-EtherCat, however, is not limited to EtherCat. By employing the “black channel” approach, the safety quality is independent of the communication channel: EtherCat, Ethernet, other fieldbus systems, underlying sub-bus systems and even wireless communication links are allowed, the ETG said.
This is confirmed by the certification of the notifying body TÜV SÜD and is used in practice: Safety-over-EtherCat data containers are routed via standard controllers and even gateways to neighboring systems where they are interpreted in a safe manner—thus one safety domain can successfully span the entire installation.
“Safety-over-EtherCat is simple to implement, bus independent and open,” says Dr. Guido Beckmann, who is in charge of the Safety-over-EtherCat Technology within the ETG. “The acknowledgement of this well-proven safety protocol as an international standard is yet another logical step toward the proliferation of EtherCat technology. It provides additional assurance to both device manufacturers and end-users who can depend on a stable and globally-accepted technology.”
