User Guide Desktop PC 8288, 8297, 8326, 8329, 8342, 8380
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  C.  Manual  modem  commands  37










