I my previous job we used "Moxa Serial to Ethernet Converter" [read-only in one way] to connect with almost 100 machines in various laboratories around the coun

I my previous job we used "Moxa Serial to Ethernet Converter" [read-only in one way] to connect with almost 100 machines in various laboratories around the country to get spectography(and other "BIG OIL" stuff) data into my distributed SQLITE and MS-SQL databases back in HQ. Worked really well. One of the oldest machine was some 286 connected to some freaky gasoline density aparatus :) In many cases you can't simply upgrade software, as software for such machines does not support anything else - and you can't really reverse engineer drivers for 50 different machines in sane amount of time. Most of really expensive machines provide some kind of output over serial interfaces - it seems to be industry standard, but I forgot the name for it.