Re: Elevator interface
Article says 80s, so probably not very since RS485 came about in early to mid 80s. Current loop would've been around for sure.
Quite a few implementations in those days supported current loop option, so may not even had necessarily needed converters. The article doesn't mention distance, but sounds long enough for current loop to be the more sensible option especially since lower maximum data rate would not have been an issue.
Biting the hand that feeds IT
