If there is wifi or wired ethernet available at the pool equipment you can test/implement it with any of an array of things like an old 2-series all the way up to the current cen com2 whatever box..? Sounds like they lost the interface though, so that is a bummer.
Thank.? I wish that was an option.? The issue is it would cost a butt load of money to trench to the two Jandy systems, add lightning protection, and then even find an RS Interface.? The current single RS interface was working until someone apparently slice that line somewhere in the yard.? Then replaced the Jandy controller.? And no one knows how it gets in the house.
That serial interface might still work.? I would test it before abandoning something that works.? I have one operating on an iAquaLink system, although the Jandy folks say it won¡¯t work