Epson ESC/VP21 User Manual page 20

&Dn DTR Option
This command controls how the modem responds to DTR, After toggling DTR,
the host should wait 200 ms before modifying the UART registers or sending a
new command to the modem as the modem does not send an 'OK' message to
indicate it has performed the requested function.
&D0
&D1
&D2
&D3
Note :
&F
Fetch Factory Configuration
command loads command and S-register factory defaults into the active configura-
This
tion, and configures the modem for data mode.
12
In asynchronous mode (&Q0), the modem
ignores DTR.
The modem switches from data mode to
command mode when an on-to-off transition
of DTR occurs.
An on-to-off transition of DTR causes the
modem to go on-hook (hang-up) and disable
auto-answer mode. Auto-answer mode (S0
is not equal to zero) is enabled when DTR is
turned on. (default)
An on-to-off transition of DTR re-initializes
the modem. The re-initialize procedure
performs a power-up reset, except that the
UART registers are not re-configured,
The modem will not respond to a DTR toggle
in sleep or power down mode (see S-register
S30) It is recommended that a character be
sent to wake up the modem prior to toggling
DTR.
COMMAND REFERENCE - 2