Patent ID: 8396060

Claim:
A network control system for packet-transmitting a manipulated variable (“MV”) of a controller, which is calculated based on a deviation between a processed variable from a sensor that measures a physical quantity of a controlled object plant and a set value at a predetermined sampling period, to an actuator provided on a controlled object plant side via a network, and causing the actuator to provide the manipulated variable to the controlled object plant, the network control system comprising: an MV complementing unit that provides a complementary value of the manipulated variable to the actuator when an error occurs in a packet transmission; an MV buffering unit that answers back trend data of the manipulated variable being provided to the controlled object plant from the actuator or the complementary value being complemented by the MV complementing unit for the actuator, to the controller via the network; and an MV compensating unit that corrects a calculation of the manipulated variable of the controller based on the trend data or the complementary value being answered back, wherein the MV compensating unit calculates a virtual set value (“SV”) based on the trend data or the complementary value being answered back and the trend data being held on the controller side, such that an amount of the manipulated variable obtained from a sampling at a time of occurrence of the error in the packet transmission to a current sampling coincides with a value of the trend data, and then corrects/calculates the manipulated variable in the controller from the virtual SV.