Safety Control Data Refresh During Program Changes

The patent segments the control program into two distinct parts: safety control programs that must continue executing without interruption, and general control programs that can be modified. This segmentation allows the safety control unit to selectively stop only the general control programs during program changes while maintaining continuous execution of safety control programs, thereby resolving the contradiction between program adaptability and safety control reliability.

The patent implements dynamic control over program execution by introducing a selective stop mechanism. The safety control unit dynamically determines which programs to stop based on their classification (safety-related vs. general control), allowing flexible program modification while preserving safety control continuity. This dynamic approach enables the system to adapt program execution behavior according to the specific modification needs while maintaining safety guarantees.

The patent ensures continuous execution of data refresh operations that are related to safety control by excluding them from the stop command issued during program changes. The safety control unit specifically identifies and maintains data refresh processes that feed safety control data, allowing these useful actions to continue uninterrupted while other non-critical data refresh operations may be paused. This selective continuity maintains safety control productivity while enabling program modification.

The patent segments data refresh operations into safety-critical data refresh (which continues) and non-critical data refresh (which may stop). This segmentation allows the system to perform program modifications with minimal interruption to overall system productivity by maintaining only the essential safety-related data input streams while pausing other operations.

The patent segments programs into safety-critical programs and general control programs, allowing selective stopping of only the general control programs during modifications. This segmentation enables safe program changes in the general control portion while maintaining operation of safety control programs and their associated external devices, thereby improving ease of operation during maintenance without compromising program change safety.

The patent applies preliminary anti-action by pre-identifying and protecting safety control programs from being stopped during program changes. Before initiating a program modification, the system determines which programs are safety-critical and prevents their interruption, thereby counteracting the potential harmful effect of unnecessary safety device stops while still allowing safe modification of non-critical programs.