David Burgess wrote:
> If I understood you you're saying I should just construct a really
> long null modem cable using cat5. Interesting.
> 
> My searches aren't turning up anything by Rob Whitney on the topic,
> but I'll keep looking. Anybody have any pointers on building a 15m
> serial cable, perhaps from cat5 or cat6? I guess I could use the
> charts here (http://www.zytrax.com/tech/layer_1/cables/tech_rs232.htm#rj45)
> to match the pinouts on the db9.

How about this?
http://www.amazon.com/RJ45-Db9-Serial-Connector-Converter/dp/B00006BBTJ

Any adapter should work, as a DB9 has some unused pins in serial config. 
  I have no clue on the distance limitations, however.

			Lee