RS232 DB9 Serial Loopback for Norton
The PC loopback plug is a useful diagnostic tool. The loopback plug connects serial inputs to serial outputs so that the port may be tested. There is more than one way to wire up a loopback plug - but this is the most common. Used to verify that a port is working. This one works with Norton Utilities: Norton Diagnostics from Symantec.
 | DB9 pin D-SUB male (at the computer) |
| Name | Pin | Pin | Pin | Pin |
|---|---|---|---|---|
| Jumpering 1 | 2 | 3 | ||
| Jumpering 2 | 7 | 8 | ||
| Jumpering 3 | 1 | 4 | 6 | 9 |
DB9 loopback (variant #1)
DB25 loopback (variant #1)
DB25 loopback (variant #2)