[c-nsp] Max length of 9600 serial over CAT5e

[Seth Mattinen]

Bill Wichers wrote:
> RS-232 has more limitations than just cable capacitance. RS-232 is a
> single-ended communication protocol (on the physical level), so it's
> noise immunity is not very good. This is especially a problem if you're
> running the cable in an electrically noisy environment (like a cable
> tray or wiring closet(s), etc.).
> 
> If you need to run a long distance, why not just convert your RS-232
> signal to RS-422 where you can safely run a 9600bps signal out to over a
> kilometer? All you need is a 2 pair cable, ideally with a shield,
> provided you don't need hardware flow control. The converters are
> usually cheap, maybe $50 or so per end unless you need electrical
> isolation.
> 

I'll second the 422. It's not worth running 232 for long distances. The
converter cost is trivial. Plus if you're stuck running serial through a
1/2" conduit not having that DB9 connector makes the job so much easier.

~Seth