Epson 900 - Manual (Page 85)

Make sure the other drvice is IrDA-
compliant.
Make sure that the communicating IrDA
ports are within three feet of each other,
and are positioned at an angle of 30° or
less.
Check that the IrDA port’s COM
assignment is correct. The default setting
is COM2.
Check that the Serial Port 2 options are set
to IR and to the correct address.
Troubleshooting 7-19