Multimedia applications in industrial networks: integration of image processing in Profibus

This paper analyzes the transmission of images through Profibus for applications concerned with the processing of images integrated in control systems, by means of a detailed study of two real cases with different bandwidth requirements. We analyze the special features of an artificial vision system making use of Profibus as a transport system, the scheduling of the traffic in order to guarantee the delivery of the images and the control traffic before their deadlines, the protocol used, and the compression techniques usable in this kind of system, which enable us to reduce the necessary bandwidth for the applications without degrading the operation of the image processing application. We prove that this integration is currently viable in applications with medium-sized bandwidth requirements, above 17 Mb/s, and coexisting with control traffic, while current control techniques prevent its use in systems with greater bandwidth requirements, in particular in the application with 53 Mb/s requirements.