Title :
The cyclic services in an industrial network
Author_Institution :
Dept. of Comput. Eng., Swiss Federal Inst. of Technol., Lausanne, Switzerland
Abstract :
In Profibus master stations poll data from slave stations using the cyclic service-CSRD (Cyclic Send and Request Data with Reply). Because the polling-interval determines the data sampling interval, it is important for the Profibus user to be able to know the maximum polling-interval of a cyclic service. In this paper we develop a formula for determining the maximum polling-interval of a cyclic service. Furthermore, if the polling-interval of a cyclic service cannot be met, then we can repeat the corresponding cyclic service in a poll list to reduce the polling-interval. However, how are the repeated cyclic services to be positioned in the poll list? The approach we use is an equi-distance one
Keywords :
computer networks; system buses; Profibus; cyclic services; industrial network; polling-interval; Actuators; Data communication; Data engineering; Feedback control; Field buses; Intelligent networks; Master-slave; Sampling methods; Sensor phenomena and characterization; Sensor systems;
Conference_Titel :
Real-Time Computing Systems and Applications, 1996. Proceedings., Third International Workshop on
Conference_Location :
Seoul
Print_ISBN :
0-8186-7626-4
DOI :
10.1109/RTCSA.1996.554980