Is there a non-Otis solution that allows these existing Otis serial/multi-drop operator to be replaced, without having to get the Otis controller reconfigured to use a discrete door interface (assuming that is even possible)?
This might allow them to continue to maintain these units rather than paying for another newer Otis door operator like a Glide A that locks them into buying even more Otis spare parts (or locks them out if it requires an Otis mechanic with special tools). If the building owner decided to modernize the controllers (which would be an expensive "nuclear option" to get away from Otis proprietary equipment), that Glide A might not be compatible with the next control system.
A lot of those older Otis controllers like E411 seem to "just work" for many years with some TLC, but door operators inevitably wear out mechanically or the drive motors and electronics die from millions of open-close cycles.
42” side slides, doors tend to bang open so i have to adjust the openoffset, unitec says its because my doors are “a little on tbeogbtvside”