Abstract: A method and apparatus for detecting an endless loop in a rules-based expert system. This is preferably accomplished by maintaining a count for each of the rules during rule processing. The count indicates the number of times a corresponding rule is executed by the rules based expert system. If the count corresponding to any of the rules exceeds a predetermined value, it is concluded that the rules-based expert system is stuck in an endless loop, and the rules-based expert system is interrupted.

Abstract: When implementing services compiled of service independent building blocks (SIB) in an intelligent network, the SIB parameters to be relayed in computer instructions are replaced with a global data structure, whereby no parameters at all are transferred in the instruction call. Having no parameters means that each SIB receives the parameters it needs from one global variable. The global variable is visible to all SIBs, whereby each individual SIB fetches the parameters it requires from it. As regards some SIBs it is rather certain that they will remain unchanged and thus really service independent, but for some there is no such certainty, and for this reason the SIBs may be divided logically into two groups: assisting and performing SIBs respectively. Parameters of the performing SIBs are not relayed in the sub-programme call, but in one or several global data structure variables.

Abstract: A device in accordance with the present invention includes drive circuitry (110) coupled to a plant (120). The drive circuitry (110) generates a first set of command signals to transition the state of the plant (120) from an initial state to an intermediate state at a first discrete time. The drive circuitry (110) generates a second set of command signals to transition the state of the plant (120) from the intermediate state to the final state at a second discrete time. A state estimator (130) is coupled to the plant to detect the state of the plant (120). A method for changing the state of a plant (120) is also provided. The method includes the steps of transitioning the plant (120) from a first state to a selected state at one of a plurality of discrete times, each of the discrete times being separated by at least one discrete time interval, and transitioning the plant (120) from the selected state to a final state at another of the plurality of discrete times.