Method for modifying data

A method for modifying data to be used by a program of a data processing system for controlling an assembly, the data being stored in a first memory as reference data associated with memory addresses in the first memory, the memory addresses in the first memory being stored in a reference data memory address table of the first memory in order to be addressed by the program, and the reference data including a portion to be modified and another portion to be left unmodified, the method comprising the steps of:

• a) copying the reference data memory address table to a second memory as a working data memory address table in order to be addressed by the program;
• b) copying the portion of reference data to be modified to the second memory as working data to be modified, the working data to be modified being associated with memory addresses in the second memory;
• c) modifying the working data memory address table in order to replace the memory addresses of the portion of reference data to be modified in the first memory with the memory addresses of the working data to be modified in the second memory;
• and
• d) modifying the working data, wherein the working data to be modified is modified during an execution of the program.