How To Make A Serial RS-232 Loopback Connector with a Cisco Adapter
This video will show you how to make a serial loopback connector for a Cisco EIA/TIA RS-232 Adapter. The simple RJ-45 loopback plug will allow you to loop the transmit to receive, so that you can effectively test a Com port or USB to serial adapter. Something to throw into your toolbox along with you EIA/TIA adapter.
Full plans can be found at http://www.networkedminds.com/make-rs-232-loopback-plug-cisco-adapter/