I am assuming you would like to run a long RS232 DB9 cable between floors/walls etc... The monoprice CAT RJ45 to RS232 may be a great option and if it is Phoenix, XLR or some other type of connector you may want to run a shielded signal cable with a positive, negative and a ground. Would help to know what 2 devices you are trying to connect and the distance.
-- Thanks, Anil A. Apple Communication LLC. www.apple-link.com Pro-AV - Pro Lighting - Networking - Security Cameras - Home Theater For all your low voltage cabling needs
