PROFIsafe

PROFIsafe (PROFIBUS safety or PROFINET safety) is the first open functional safety communication technology for distributed automation systems worldwide. Its specification for PROFIBUS DP and PROFIBUS PA was published first back in spring 1999. It incorporates the knowledge of more than 25 renowned safety companies. Extensions for the Ethernet based PROFINET IO followed in fall 2005. More than 30,000 automation systems with more than 300,000 PROFIsafe nodes are currently in use worldwide (spring 2007).

In the past, safety automation had to be "hard-wired" and based on "relay" technology due to existing international standards. This changed with the advent of a new standard – IEC 61508 – specifying how microcontrollers and software can be used in safety automation. This triggered the development of PROFIsafe, which was to integrate safety into the existing standard PROFIBUS fieldbus technologies. PROFIsafe is designed as a separate layer on top of the fieldbus application layer and reduces the error probability of the data transmission to the level required by or better than the relevant standards. PROFIsafe messages are using the existing standard fieldbus cables in coexistence with the standard messages ("Single Channel"). PROFIsafe does not benefit from any error detection mechanisms of underlying transmission channels and thus supports the securing of whole communication paths, even backplanes inside controllers or remote I/O. PROFIsafe coined the term "Black Channel" for this concept, which now is adopted by most of the other safety fieldbusses. PROFIsafe can be used in safety applications up to Safety Integrity Level 3 (SIL) according to IEC 61508, Performance Level "e" (PL) according to ISO 13849-1, or Category 4 according to EN 954-1.

PROFIsafe is using expanded fault (errors and failures) detection mechanisms such as

* Consecutive numbering
* Timeout monitoring
* Source/destination authentication
* Cyclic redundancy checking (CRC)

PROFIsafe is standardized in IEC 61784-3-3. It also is a Chinese standard (GB/Z 20830-2007).

PROFIsafe runs its own web portal on www.profisafe.net (see Web Links) with more details on the technology and hints for device developers, integrators and end users.

The PROFIsafe standard is maintained, updated and marketed by PROFIBUS International, a non-profit organisation administered from Karlsruhe in Germany. PROFIBUS International is also responsible for the development of PROFIBUS and PROFINET, an Ethernet based fieldnetwork.

External links

* [http://www.profibus.com PROFIBUS International]
* [http://www.profisafe.net PROFIsafe web portal]