Editing Hayes AT command set (section)

=== Example session ===
The following represents two computers, computer A and computer B, both with modems attached, and the user controlling the modems with [[terminal emulator]] software. Terminal-emulator software typically allows the user to send Hayes commands directly to the modem, and to see the responses. In this example, the user of computer A makes the modem dial the phone number of modem B at phone number (212) 555-0100 (long distance). After every command and response, there is a [[carriage return]] sent to complete the command.

{| class="wikitable"
! Modem A !! Modem B !! Comment
|-
| '''ATDT12125550100''' || || User at modem A issues a dial command: AT-Get the modem's ATtention; D-Dial; T-Touch-Tone; 12125550100-Call this number
|-
| || ''RING'' || Modem A begins dialing. Modem B's phone-line rings, and the modem reports the fact.
|-
| || '''ATA''' || Computer at modem B issues answer command.
|-
| ''CONNECT'' || ''CONNECT'' || The modems connect, and both modems report "connect". (In practice, most modems report more information after the word CONNECT — specifying the speed of the connection.) Also, at this time, both modems will raise the DCD, or Data Carrier Detect signal, on the serial port.
|-
| '''abcdef''' || ''abcdef'' || When the modems are connected, any characters typed at either side will appear on the other side. The person at computer A starts typing. The characters pass through the modem and appear on computer B's screen. (User A may not see his own typed characters — depending on the terminal software's [[echo (computing)|local echo]] setting).
|-
| || '''+++''' || The person at computer B issues the modem escape command. (Alternately, and more commonly, the computer B could drop the DTR, or Data Terminal Ready signal, to achieve a hangup, without needing to use +++ or ATH.)
|-
| || ''OK'' || The modem acknowledges it.
|-
| || '''ATH''' || The person at computer B issues a hang up command.
|-
| ''NO CARRIER'' || ''OK'' || Both modems report that the connection has ended. Modem B responds "OK" as the expected result of the command; modem A says [[NO CARRIER]] to report that the remote side interrupted the connection. The modems on both sides drop their DCD signals as well.
|}