Abstract: A multi-tasking operating system for real-time control of industrial processes integrates ladder type programs and state-type programs by viewing each as a series of instructions with an implicit pointer list pointing to the next instruction. A fixed number of instructions of each program task are executed after which the effective pointer to the next instruction is stored toward the next time that task is invoked. Multiple tasks that need to be coordinated can be linked with subtasks that can be guaranteed complete execution by allocating sufficient instructions to those subtasks.

Abstract: A processor that executes coded instructions using an instruction scheduling unit receiving the coded instructions and issuing an instruction for execution. A replay signaling device generates a signal indicating when the instruction failed to execute properly within a predetermined time. A replay device within the instruction scheduling unit responsive to the signaling device then reissues the instruction for execution.

Abstract: An image processing system having programmable keys for recording frequently used procedures is disclosed. The scanner comprises a scanning module for scanning an document, a plurality of programmable keys for recording frequently used procedures and a program key. The computer comprises a script file generation program for generating a script file of the programmable key. The script file is generated by using the following steps: (1) press the program key to generate a script file, (2) press a programmable key to relate the script file to the programmable key, (3) generate a plurality of control signals sequentially through various control keys of the scanner, (4) store the control signals in the script file, and (5) press the program key to complete the script file.