US Robotics 56K USB Modem User Manual page 30

&D<value>—Data Terminal Ready (DTR) Control
Use this command to select the modem's response to the data terminal ready (DTR) signal. The host
system generates the DTR signal and supplies it to the modem.
Result codes:
• OK if <value> = 0—3.
ERROR if <value> ≠ 0—3.
•
Table 26. &D<value> Commands
Command*
&D0 Modem ignores the true status of DTR and treats it as always on. Use this command if
the computer does not provide DTR to the modem.
&D1 If the DTR signal is not detected while in online data mode, the modem enters command
mode, issues the OK result code, and remains connected.
&D2 If the DTR signal is not detected while in online data mode, the modem disconnects
(default).
&D3 Resets modem on the on-to-off DTR transition.
* ITU-T Recommendation V.250 (05/99) standardized this command. However, the standard does not include the additional func-
tionality added with the D3 command.
&F<value>—Restore Factory Default Configuration
Use this command to reset the modem to the configuration programmed at the factory. This operation
replaces all of the command options
values.
Note: In voice mode, the command line is ignored if the AT&F command is placed on the same line as the
other commands. To load factory settings in voice mode, issue the &F<value> command by itself.
Result codes:
• OK if <value> = 0.
ERROR if <value> ≠ 0.
•
Table 27. &F<value> Commands
Command
&F0 Loads the configuration stored and programmed at the factory (default).
&G<value>—V.22bis Guard Tone Control
Use this command to select which guard tone, if any, the modem sends while transmitting in the high band
(answer mode). This command is only used in V.22 and V.22bis mode. This option is not used in North
America; it is for international use only.
Result codes:
• OK if <value> = 0—2.
ERROR if <value> ≠ 0—2.
•
1. There are several noted exceptions to this command and caution should be used when determining the state of the command
options once this command has been executed.
Function
1
and S-register settings in the active configuration with factory default
Function
56K USB Modem
User Guide
Command Reference - 24