In a circuit simulation system, a storage section is configured to store a circuit data, an analysis condition data and an output data. The inclination of the central axis of the main shaft is changed with respect to the axis of rotation of the eccentric shaft by a gear transmission comprising cog wheels, such that the magnitude of the constrained stroke motion changes. The second stage includes a driving controller, a driver, a sustain part, and a controller. The relay-to-relay direct communication system also includes a second protective relay directly coupled to the first protective relay via a communication link.