In a control apparatus allowing control programs and information programs to coexist, execution management data that indicates the upper limit of resources that are resources usable by the programs is enabled to be appropriately changed. The control apparatus downloads at least one of one or more object programs (one or more programs among one or more control programs and one or more information programs) from a program distribution apparatus via a network and one or more network ports. At timing different from the timing of the download, the control apparatus changes the execution management data that indicates the upper limit of resources that are resources usable by the object program in relation to a plurality of computing resources of the control apparatus. Each control program is a program that performs a scan operation of outputting control information on the control object apparatuses coupled to I/O ports. Each information program is a program that performs information processing different from the scan operation.

A control apparatus where control programs and information programs coexist is allowed to change programs flexibly. The control programs and information programs are installed in the control apparatus, which is provided with a shared area. The shared area is an area that at least one control program and at least one information program can access. Shared information is stored in the shared area. The shared information includes at least one of information related to an I/O port accessed by the control programs, and information related to the control program. Each control program is a program that performs scan operation of outputting control information on the relevant control object apparatus coupled to the I/O port accessed for controlling a control object apparatus with respect to the control program, to this I/O port. Each information program is a program that performs information processing that does not include the scan operation.

A control apparatus where control programs and information programs coexist is allowed to change programs flexibly. The control programs and information programs are installed in the control apparatus, which is provided with a shared area. The shared area is an area that at least one control program and at least one information program can access. Shared information is stored in the shared area. The shared information includes at least one of information related to an I/O port accessed by the control programs, and information related to the control program. Each control program is a program that performs scan operation of outputting control information on the relevant control object apparatus coupled to the I/O port accessed for controlling a control object apparatus with respect to the control program, to this I/O port. Each information program is a program that performs information processing that does not include the scan operation.