Dsr Signal Handling; Dcd Signal Handling - Telebit T3000 Reference Manual

DSR Signal Handling
The &S command determines how the modem
handles the Data Set Ready control (DSR) signal.
&SO The DSR signal is always ON.
&S1 The DSR signal goes ON when the modem
detects an answer tone, and it stays on throughout
the connection.
&S2 The DSR signal is always ON except when it goes
OFF for a period of time set by the S47 register
while disconnecting a call.
&S3 The DSR signal goes ON when DTR is turned ON
or when the modem detects a carrier and DTR is
present. DSR goes OFF when DTR is dropped or
the carrier is lost.
&S4 DSR follows DCD. DCD is ON when a carrier is
detected.
DCD Signal Handling
The &C command determines how the modem
handles the Data Carrier Detected (DCD) control
signal.
&CO The DCD signal is always ON.
&C1 When a carrier is detected from the remote
modem, the DCD signal is turned ON after the
CONNECT result code is sent to the DTE. DCD is
turned OFF when the carrier is dropped.
&C2 The DCD signal is always ON except when it goes
OFF for a period of time specified by the S47
register while disconnecting a call.
&C3 The DCD signal is the inverse of the CTS signal.
4-14 Beyond the Basics