DATA ACCESS IN DISTRIBUTED CONTROL SYSTEMS

Abstract: When dealing with distributed control systems, the notions of nodes, messages, timetables, etc. are usually not transparent from the control application designer view. For that reason, in the IFATIS platform, the distributed shared memory model has been introduced to decouple the control application design from the issues of the hardware implementation. To cope with that, for the control application, the underlying communication system and peripheral devices are only exposed as a set of data cells. Two processes can use such a cell to communicate with each other regardless of their current location. If they reside in different nodes, data written to a cell is transparently distributed through the system by means of statically scheduled TTCAN messages. For automatic data transformation and fault detection, each data cell can be associated with a validation and/or transformation routine. To utilize this approach control application development tools (Matlab/Simulink and ControlBuild) have been adapted. Copyright © 2005 IFA