The use of fieldbuses in automation systems instead of hard wired interaction between components provides a number of well-known advantages like lower costs, more flexibility, new functionalities and higher dynamics. For interactions which are needed to fulfill safety requirements, hard-wired connections are still being used in parallel to the fieldbus wire. In order to reap the aforementioned advantages for the case of safety connections, a safety protocol needs to be integrated into the fieldbus communication layers. The inherent failure rate of fieldbus protocols is generally much higher than that allowed in international standards for safety applications. This paper will focus on the steps that are required to adapt the safety protocol CIP Safety™ to a non-CIP fieldbus. It will explain in detail which steps with respect to specification, TÜV involvement, and conformance testing software modification have to be taken to make CIP Safety the safety protocol of a fieldbus. This paper will use the example of the successful CIP Safety integration on top of the existing sercos III communication layer.
Paper and presentation from the 2012 ODVA Industry Conference & 15th Annual Meeting
Lechler, Schlechtendahl, Leurs, Verl
Institute for Control Engineering of Machine Tools and Manufacturing Units (ISW) University Stuttgart