Loopback Adapter Tester Plug Serial DB25-F DB9-F (RS232)
A very nice addition to any tech's tool kit.
These work great and can test additional wires besides just the send and recieve.
DSUB 9 Female Connector
DSUB 25 Female Connector
Wiring Wired Together DB-25 port: 2-3, 4-5, 6-8-20-22. DB-9 port: 3-2, 7-8, 6-1-4-9.Originally Used with IBM PC Diagnostic Software.
Used with Checkit Software.
For a fast test install and use Terminal it should echo back.
Technical Drawing for Part PCC-31020