User`s manual

U.S. Robotics I-modem Command Reference
Appendix A: Alphabetic Command Summary • Page A-21
&Sn Send the computer a Data Set Ready (DSR) signal via the EIA-232 interface.
(ÒData SetÓ is industry jargon for modem.)
&S0 DSR is always ON (override).
&S1 In Originate mode: Send DSR after dialing, on detection of the remote
deviceÕs answer tone. In Answer mode: Send DSR after sending an answer
tone.
&S2 When Carrier is lost, send a pulsed DSR signal with Clear to Send (CTS)
following Carrier Detect (CD). This option is for specialized equipment
such as automatic callback units.
&S3 Same as &S2, but without the CTS signal.
&S4 Send the computer DSR at the same time as CD.
&S5 Send DSR normally, and follow CTS with CD.
&Tn Test the I-modem.
&T0 End testing.