A precisely timed fully parallel process input/output facility for control applications

Contemporary real-time computers are unable to manipulate external parallel processes simultaneously, and their response times are generally unpredictable. It is shown that these problems can be solved by endowing process control computers with input/output facilities, working fully in parallel, and making use of exact time specifications. The required system functions are compiled, the design of the additional hardware components is given, and the supporting elements needed in high-level languages and real-time operating systems are discussed. As a by-product, the exact timing feature of input/output operations opens a new way of synchronising the access of multiple tasks to shared peripherals, which is based on the parameter time.