Abstract: According to one embodiment, a control program maintenance device includes a display processing unit that displays whether a first control program and a second control program are matched or mismatched on a display unit as a result of comparison. When a mismatch occurs, the display processing unit develops the configuration to a lower level by referring to a product tree; displays different parts in the control programs within the range to be compared on the display unit; and displays, in a developable manner and by referring to the product tree, mismatch parts in the control programs of a comparison source and a comparison destination before and after maintenance work is performed on a control program to be maintained.

Abstract: According to one embodiment, a control program maintenance device includes a display processing unit that displays whether a first control program and a second control program are matched or mismatched on a display unit as a result of comparison. When a mismatch occurs, the display processing unit develops the configuration to a lower level by referring to a product tree; displays different parts in the control programs within the range to be compared on the display unit; and displays, in a developable manner and by referring to the product tree, mismatch parts in the control programs of a comparison source and a comparison destination before and after maintenance work is performed on a control program to be maintained.

Abstract: According to one embodiment, a plant control system includes a station mounting controllers thereon, an engineering device which manages programs, and a device which connects the controllers and the engineering device. The engineering device includes database which stores information on a first variable for allowing data to be shared among programs in each controller and a second variable for allowing data to be shared among programs in the station, the database management part, and a relocate management part which moves the program, and the relocate management part includes a designating module which designates an execution order of programs in a source controller, one or more programs to be moved, a destination controller, and the source controller, a module which moves the program as designated in the designating module, and a changing module which, when the program is moved, moves or copies the first and second variable used in the program.

Abstract: According to one embodiment, a plant control system includes a station mounting controllers thereon, an engineering device which manages programs, and a device which connects the controllers and the engineering device. The engineering device includes database which stores information on a first variable for allowing data to be shared among programs in each controller and a second variable for allowing data to be shared among programs in the station, the database management part, and a relocate management part which moves the program, and the relocate management part includes a designating module which designates an execution order of programs in a source controller, one or more programs to be moved, a destination controller, and the source controller, a module which moves the program as designated in the designating module, and a changing module which, when the program is moved, moves or copies the first and second variable used in the program.

Abstract: A debug system is provided with a control program compilation processing unit 11a that generates a control program for producing a first instruction for designating a connecting state on an input side of a connecting point with respect to the connecting point for connecting symbols, its connecting destination, a first internal variable, a second instruction for designating a connecting state on an output side of a connecting point and its connecting destination, and a second internal variable; and a wire force processing unit 11b that commands that the first instruction and the first variable are rewritten to a third instruction and a third variable or that either one of the first instruction and the first variable is rewritten to the third instruction or the third variable and commands that the second instruction and the second variable are rewritten to a fourth instruction and a fourth variable or that either one of the second instruction and the second variable is rewritten to the fourth instruction or the