User`s manual

U.S. Robotics I-modem Command Reference
Controlling EIA-232 Signaling • Page 6-1
Chapter 6
Controlling EIA-232 Signaling
The EIA-232
1
interface deals with the signals and voltages used when data is exchanged
between a computer and a serial device, such as a modem or serial printer.
While external I-modems have physical serial ports, internal I-modems have virtual serial
ports. Even though you canÕt see the internal I-modemÕs serial port, the commands
described in this chapter affect its internal serial communications.
Controlling EIA-232 Signaling
Data Terminal Ready
Your computer sends a Data Terminal Ready (DTR) signal to the I-modem when it is
ready to send and receive data (use &Dn to tell the I-modem how to deal with the DTR
signal).
1. The EIA-232 standard was formerly known as RS-232 (RS stands for Recommended Standard).