Extended AT commands
Command Function
&C_ &C0 Force Carrier Detect Signal High (ON)
&C1 Turn on CD when remote carrier is present
&D_ &D0 Modem ignores the DTR signal
&D1 Modem returns to Command Mode after DTR
toggle
&D2 Modem hangs up, returns to the Command
Mode after DTR toggle
&D3 Resets modem after DTR toggle
&F_ &F Recall factory default configuration
&G_ &G0 Guard tone disabled
&G1 Guard tone disabled
&G2 1800 Hz guard tone
&K_ &K0 Disable flow control
&K3 Enable RTS/CTS hardware flow control
&K4 Enable XON/XOFF software flow control
&K5 Enable transparent XON/XOFF flow control
&K6 Enable both RTS/CTS and XON/XOFF flow
control
&M_ &M0 Asynchronous operation
&P_ &P0 US setting for off-hook-to-on-hook ratio
&P1 UK and Hong Kong off-hook-to-on-hook ratio
&P2 Same as &P0 setting but at 20 pulses per
minute
&P3 Same as &P1 setting but at 20 pulses per
minute
&R_ &R0 Reserved
&R1 CTS operates per flow control requirements
&S_ &S0 Force DSR Signal High (ON)
&S1 DSR off in command mode, on in on-line
mode
&T_ &T0 Ends test in progress
&T1 Perform Local Analog Loopback Test
&T3 Perform Local Digital Loopback Test
&T4 Grant Remote Digital Loopback Test request
by remote modem
&T5 Deny Remote Digital Loopback Test request
&T6 Perform a Remote Digital Loopback Test
&T7 Perform a Remote Digital Loopback Test and
Self-Test
&T8 Perform Local Analog Loopback Test and
Self-Test
&V &V0 Displays Active and Stored Profiles
Appendix A. Manual modem commands 47
