Shared Data on InterBus

InterBus is a fieldbus system with cyclic operation making use of a total frame protocol. It is very well suited for real time applications. The additionally defined PCP (peripherals communication protocol) is designed for the exchange of numerous data without hard real time demands, eg. parameters and program downloads. “Shared Data” is a new approach presented in this paper which enhances the features of PCP. It offers a data channel on InterBus generally useable both for tasks similar to PCP and for temporary real time connections among a small number of partners. The shared data channel allows data transfers marked with specific transfer codes directing data to a predefined number of modules. An immediate read out of data of modules is possible as well as a transfer of multiple data within the same execution cycle.