Control Places

The control systems are initiated in order to permit the operational mode of the module to be manipulated by the exogenous decisions or controls that is made by the DMS of the whole systems. A control place is mostly represented by concentric circles and can enclose either 0 or 1 token. A token in that a place portrays such the output transition of this place is enabled if the other input place of this transition encloses at least one token. Firing an output transition of the control place does not conclude in the token enclosed in the control place. In essence, the condition of the control place depends on the exogenous decisions that are made outside the part of the module modeled via the decision tree timed Petri nets.