I always find myself interfacing with old (or new) equipment for which you're expected to have a proprietary cable. Instead, I have breakout boards for every kind of connector I've ever come across (except RJ-style 10P10C and 4P4C connectors that have stumped me) and I make whatever kind of cable I need on the spot, usually with a length of CAT6 cable between boards. DB9, DB15, DB25, centronics 25-pin and 50-pin, RJ45, RJ12, several molex, etc. M/F breakouts like this:

 

One Manuf that made great both, pre-made and customizable BOB's was Wiedmuller, I collected many over the years, usually surplus as they could be quite pricey
Same DIN rail mounting feet.

 

I worked with it for many years with no problem, as long as you understood it and respected the protocol.
As per post #4, many of the CNC M/C's of the last century are still producing today and use it.
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Hard to figure but in a few days it will mark 9 years since I retired and most of the data acquisition systems I worked with are still in use today at the facility I retired from. I still keep in touch with the people still in my old department. The stuff still works just fine. Never had much to do with the CNC areas but my old department of Assembly and Test is still using RS232 and it still works fine.

Still have a few break out boards too.


Ron

 

Those folks who understood RS232 and were able to understand how to make it work with the software running on the computers and other devices they were using did not have the problems. The unfortunate ones were those folks who did not understand, whose software packages provided either no hints of the functioning, and those folks who became lost in the technical jargon and strange definitions used by the others who either were unable to explain clearly or had no intention of ever providing correct information. And there were more than a few of THOSE characters at the time.

 

Actually the RS232 protocol was very much laid out in detail I found.
Those that "got lost in the technical jargon" probably would have difficulty regardless.
One early primary reason for using the hardware H.S. was due to the fact that much remote equipment was often controlled, i.e. switched on and off, or started, at the beginning and end of transmission, such items as paper punch, tape reader etc.