User`s manual

U.S. Robotics I-modem Command Reference
Appendix A: Alphabetic Command Summary • Page A-22
&T3 Start local digital loopback testing.
&T4 Grant a remote digital loopback test of your I-modem.
&T5 Deny a remote digital loopback test of your I-modem.
&T6 Start remote digital loopback testing.
&T7 Start remote digital loopback with self-test and error detection.
&W Write the current settings to NVRAM
.
&Yn Break handling. This command lets you send a break to stop data transfer without
disconnecting.
&Y0 Destructive, don't send break.
&Y1 Destructive, expedited.
&Y2 Nondestructive, expedited.