The purpose of the invention is the simplification of a task of changing a control program upon a control device which is in use. A support device comprises: a computing part computing, for each unit program which configures a control program, identification information according to the content of each of the unit programs; a first transferring part transferring the unit programs and the identification information which is associated with the unit programs to a control device; a generating part generating changed unit programs according to a change operation upon any of the unit programs which configure the control program; and a second transferring part transferring the changed unit programs to a control device which is in use on condition that identification information is present on the control device which is identical to the identification information which is associated with the unit programs which configure the control program.

A transport control system divides a series of data-processing operations into mutually independent processes, and causes the process execution units to execute the respective processes. The data input or output by each process execution unit is stored in the data storage separate from the process execution unit, and transfer of the data between the respective process execution units is performed via the data storage instead of being performed directly between the process execution units. By separating the processes from each other and also separating the processes from the data in this manner, without affecting process execution units other than a process execution unit to be changed and the data storage, the process execution unit to be changed can be changed to a different process execution unit.

A user program for a safety controller is created by means of a program editor. The user program has a first program portion and at least one additional program portion. The first program portion defines safety-related logical dependencies between selected sensor signals and actuator signals. The user program is compiled and linked, in order to obtain an executable original program code. The original program code is transferred to a first memory of the safety controller and executed by a processor of the safety controller. The first program portion may be modified and compiled in order to obtain a modified first code portion. The modified first code portion is transferred to a second memory of the safety controller while the original program code is executed. The modified first code portion is then executed in addition to the original additional code portion and instead of the original first code portion.

A transport control system divides a series of data-processing operations into mutually independent processes, and causes the process execution units to execute the respective processes. The data input or output by each process execution unit is stored in the data storage separate from the process execution unit, and transfer of the data between the respective process execution units is performed via the data storage instead of being performed directly between the process execution units. By separating the processes from each other and also separating the processes from the data in this manner, without affecting process execution units other than a process execution unit to be changed and the data storage, the process execution unit to be changed can be changed to a different process execution unit.

When a first program storage memory is used to load a program, a program write controller stores an updated program into a second program storage memory. When the program is loaded in a first program execution memory, a program load controller loads the updated program into a second program execution memory. When a program executor is executing the program loaded in the first program execution memory, an updated-program switch controller causes the program executor to execute the updated program loaded in the second program execution memory.