Abstract: An improvement in an industrial controller having a processor with a memory holding an I/O table used for storing inputs and outputs transmitted between the industrial controller and a controlled process, via multiple I/O devices, uses templates associated with each I/O device to define the partitioning of the I/O table for the data. The templates define data types and ordering of data required for the particular I/O device permitting the space in the I/O table to be efficiently and intuitively allocated. The templates also relate physical addresses in the I/O table to program variables used by the control program.

Abstract: A communication-efficient change log historian allows workstations having images of a shared memory to remain correlated to the shared memory. The system comprises one or more workstations connected to a microprocessor-based device which includes a memory device. The memory device includes the shared memory, and also stores a memory change list and a memory change index. The memory change list forms a list of changes which have been made to the information stored in the shared memory area, and the change index is indicative of the location of the most recent entry to the memory change list. The workstations maintain an image of the shared memory area, and store workstation change indexes which are indicative of the most recent entry to the memory change list which has also been implemented to respective images of the shared memory area in the workstations.

Abstract: A decompiler works with a compiler for an industrial controller having a user modifiable instruction table to contain code fragments necessary to compile particular instructions. During compilation, the instructions are replaced with the code fragments. Thus new instructions recognizable by the compiler may be added simply by editing this instruction table. The decompiler identifies a portion of the compiled new instructions by reference to the same instruction table used by the compiler thus maintaining compatibility with the compiler.