Implementing real-time event channels on CAN-bus

Factory automation systems connect large numbers of autonomous, cooperating devices by fieldbus networks. Fieldbuses, however, provide rather low-level communication objects and their features regarding quality aspects of communication are difficult to assess and use for applications. We present an implementation of realtime event channels on the RTLinux that uses the CAN-bus as the communication media. The real-time event channel interfaces allow applications to specify quality aspects of the communication at a high level of abstraction. The paper presents a description of the middleware architecture used in the implementation. Special attention is given to implementation issues of real-time event channels as clock synchronization and the impact of controller hardware. Finally, we provide experimental results for event channels with different QoS properties.

[1]  Jörg Kaiser,et al.  Implementing the real-time publisher/subscriber model on the controller area network (CAN) , 1999, Proceedings 2nd IEEE International Symposium on Object-Oriented Real-Time Distributed Computing (ISORC'99) (Cat. No.99-61702).

[2]  Hermann Härtig,et al.  RTLinux with Address Spaces , 2001 .

[3]  Holger Zeltwanger,et al.  Time-Triggered Communication on CAN , 2002 .

[4]  Carlos Eduardo Pereira,et al.  COSMIC: a middleware for event-based interaction on CAN , 2003, EFTA 2003. 2003 IEEE Conference on Emerging Technologies and Factory Automation. Proceedings (Cat. No.03TH8696).

[5]  Weijia Jia,et al.  Scheduling Hard and Soft Real-Time Communication in the Controller Area Network (CAN) , 1998 .

[6]  Robert I. Davis.  Dual Priority Scheduling: A Means of Providing Flexibility in Hard Real-time Systems , 1994 .

[7]  Kang G. Shin,et al.  Non-preemptive scheduling of messages on controller area network for real-time control applications , 1995, Proceedings Real-Time Technology and Applications Symposium.

[8]  José Alberto Fonseca,et al.  The FTT-CAN protocol: why and how , 2002, IEEE Trans. Ind. Electron..

[9]  T. Führer,et al.  Time Triggered Communication on CAN ( Time Triggered CAN-TTCAN ) , 2000 .

[10]  Wilfried Elmenreich,et al.  A universal smart transducer interface: TTP/A , 2000, Proceedings Third IEEE International Symposium on Object-Oriented Real-Time Distributed Computing (ISORC 2000) (Cat. No. PR00607).

[11]  Janusz Bryzek.  Introduction to IEEE-P1451, the emerging hardware-independent communication standard for smart transducers , 1997 .

[12]  Jean Bacon,et al.  Generic Support for Distributed Applications , 2000, Computer.

[13]  David S. Rosenblum,et al.  Interfaces and Algorithms for a Wide-Area Event Notification Service , 1999 .

[14]  Henrik Thane,et al.  A communication protocol for hard and soft real-time systems , 1996, Proceedings of the Eighth Euromicro Workshop on Real-Time Systems.

[15]  Thomas Bemmerl,et al.  Integration of a CAN-based connection-oriented communication model into Real-Time CORBA , 2003, Proceedings International Parallel and Distributed Processing Symposium.

[16]  Jörg Kaiser,et al.  A publisher/subscriber architecture supporting interoperability of the CAN-Bus and the Internet , 2002, 4th IEEE International Workshop on Factory Communication Systems.

[17]  Douglas C. Schmidt,et al.  The design and performance of a real-time CORBA event service , 1997, OOPSLA '97.

[18]  Gwangil Jeon,et al.  Integrating subscription-based and connection-oriented communications into the embedded CORBA for the CAN bus , 2000, Proceedings Sixth IEEE Real-Time Technology and Applications Symposium. RTAS 2000.

[19]  Jörg Kaiser,et al.  A real-time event channel model for the CAN-Bus , 2003, Proceedings International Parallel and Distributed Processing Symposium.