A control system for a machine comprising a plurality of independently replaceable machine modules comprises a controller operable to control operation of the machine. Memory stores machine data for use by the controller. Communication means are operable to provide communication for data transfer between the controller and the memory. The memory includes a plurality of memory modules associated with respective machine modules. Each of the memory modules is replaceable with the respective associated machine module and independently of other memory modules. The communication means is operable to provide communication for data transfer between the controller and a replacement memory module associated with a replacement machine module.

A method for manipulating a first function of a control program of an electronic control device, using a second function. The control program is processed using a first calculation kernel of a processor, and the second function is processed by a second calculation kernel during the processing of the control program. The first function assigns a first value to a variable and writes the first value to the storage address of the variable at a first time. The second function assigns a second value to the variable, which value is written to the storage address of the variable at a second time, wherein the second value written by the first function is overwritten. At a third time, the control program reads the second value from the storage address of the variable. A control entity coordinates the times at which the storage address of the variable is accessed.