PLCs always pack the individual Booleans into 16/32 bit registered (packed Booleans) to optimize communication – one register read request vs. 16 bit reads requests. Every control systems HMI/DCS graphics package is designed to accommodate this data structure. So matching bit patterns is an efficient way to design the display. These displays were, of course, designed before there was any consideration of the limitations of PI or any thought to historize these transient statuses.
Can PI create its own “meta integer” combining these two bit into its four possible combinations: OPEN, CLOSED, NOT OPEN OR CLOSED, and BOTH OPEN AND CLOSED?