A DIRECTED GRAPH MODEL FOR DISTRIBUTED SEQUENTIAL CONTROL

With the rapid emergence of fieldbus systems, there is a trend towards distributed control with intelligent sensors and actuators interconne cted via a communication network. This paper presents a new approach o f sequential control using fieldbus technology. The distributed sequen tial control system consists of a group of intelligent nodes of sensor s and actuators communicating with one another via a network to achiev e a sequence of control actions without a master controller. A directe d graph model has also been developed to facilitate the configuration for the distributed control system. It translates a user-defined seque nce df control actions to a Petri net model and analyses the Petri net to check feasibility of the sequence. It can also generate the necess ary network data for the distributed sequential control.