OpenSAFETY
OpenSAFETY is a communications protocol for the transmission of safety-related data in the operation of machines and other technical equipment in industrial production, in process plants or in other similar areas. Such safety data can be, for example, act to alarms that have been triggered by the fact that someone or something is advised in beams of light barriers designed to protect in a dangerous area before accidents. While conventional solutions for the transmission of such signals using special lines between the protection of on-site facilities and control systems, which are connected via special relays, openSAFETY allows the transmission of safety information without moved specifically for this kind of data cable runs. This is possible because openSAFETY a protocol bus-based is, which allows to combine safety data on existing Industrial transmit Ethernet cables. Thus, the security protocol used with Ethernet networks that were originally installed for general monitoring and control tasks and continue to be used primarily for this purpose. In contrast to other bus -enabled safety protocols with only one or a few specific industrial Ethernet implementations work and are not compatible with other systems, to openSAFETY can use with a variety of Industrial Ethernet variants.
Certification and functional features
OpenSAFETY is certified according to the standard IEC 61508 and meets the requirements for applications according to SIL 3 The protocol was approved by the national IEC committees of more than two dozen countries, approved as part of the IEC 61784-3 FSCP 13 and released for international standardization.
OpenSAFETY support functions for optimized data transmission, in particular the direct cross traffic between network devices with each other (cross- traffic), that is, the communication from terminal to terminal without going through special control units. It also offers a number of measures to ensure the integrity and accuracy of transmitted data so as timestamp, unique identifiers for data packets and more. The protocol encapsulates security data within a standard Ethernet frames. A openSAFETY frame always consists of two sub- frames, each of identical copies of one another. Each of the subframes includes a separate CRC. By thus achieved multiple backup and redundancy at multiple levels is excluded that falsification of safety data and other types of errors can occur unnoticed.
Interoperability and open source license
In contrast to earlier available bus-based safety solutions, each of which serves as a safety supplement a special Industrial Ethernet protocol or a specific protocol family openSAFETY is targeted at the general interoperability. In addition openSAFETY has been made available under a BSD license; it is so open source, while the other bus-based security solutions such as PROFIsafe, Safety over EtherCAT or CIP Safety proprietary technologies.
Originally, the now -raised in openSAFETY solution of the Ethernet POWERLINK Standardization Group (EPSG ) was developed as a safety supplement designed specifically for the supported from this user organization Industrial Ethernet POWERLINK version. This predecessor of openSAFETY was presented under the name POWERLINK Safety 2007. The further developed and now open source protocol, however, is no longer bound to POWERLINK. It is possible rather an insert with a variety of important Industrial Ethernet implementations, specifically next POWERLINK also with PROFINET, SERCOS III, EtherNet / IP or Modbus TCP. This broad interoperability with about 90 % of the 2010 global installed Industrial Ethernet networks is achieved by openSAFETY works only on the top (application) layer of the communication network. Provide for the transmission of safety data on this layer has different characteristics of different protocol versions on lower network layers no significant restrictions dar. This approach is called in communication protocols as a black channel principle.
Technology demonstration in 2010 and developments since
OpenSAFETY source protocol is available as open since 2009. The protocol is thus under the bus - based security solutions is still a young technology.
Great attention drew the open system at the Hannover Industrial Fair in April 2010 due to difficulties in the local presentation of openSAFETY four different functional implementations of the security solution has been shown that ran in network environments with SERCOS III, Modbus TCP, EtherNet / IP and POWERLINK. This technology demonstration itself and to the importance of the disclosure of the system under an open source license quickly developed a lively debate. Part violent opinions pro and con openSAFETY appeared in the German trade press during the fair and into advanced reporting.
On the openSAFETY idea in Hanover followed by a series of information events on this technology to smaller specialized events, such as a lecture at the 9th International Symposium of TÜV Rheinland in Cologne in May 2010. At this conference for functional safety in industrial applications presented Stefan Schönegger by the Austrian company Bernecker Rainer Industrie- Elektronik Ges.mbH ( B & R), which is a co-developer and primary sponsor of openSAFETY the principal features and functions of the protocol at a glance before. More events on subsequent industry forums devoted to representations by the trade press is increasingly the way of the actual configuration of the protocol and application specific questions.