User Guide

Most people use the communication software programs to tell modems what to do.
Therefore, you may not use the commands in this chapter. However, if you prefer to
communicate with your modem directly, you can type the commands described
below.
Here describes how to work in the terminal mode.
Typing Commands
Use the BACKSPACE key to delete typing errors.
Every command (except A/ and +++) must begin with the AT or at prefix and be
entered by pressing the <Enter> key.
When you see an n, replace the n with one of the letter or numeric options listed
for that command. For example, for the En command, you might type ATE1.
Basic AT Command Guide
+++Escape Sequence
An escape sequence allows the modem to exit data mode and enter on-line
command mode. While in on-line
command mode, AT commands are sent directly to the modem. Use the
return to on-line data mode command
(see O<value>—Return to On-Line Data Mode on page 15) to return to data
mode.
Place a pause before and after the escape sequence to prevent the modem
from interpreting the escape sequence
as data. The length of the pause is set by register S12 (see S12—Escape
Guard Time on page 75), the escape
guard time. Register S2 (see S2—AT Escape Character (User-Defined) on
page 73) identifies the escape
sequence character.
A/—Repeat Last Command
Use this command to repeat the last AT command. The modem repeats the
command currently in the command
buffer. Do not use the AT prefix with this command. Do not conclude the
command with a terminating character
such as enter.
A—Answer
This command instructs the soft modem to go off-hook and answer an
incoming call.
E<value>—Command Echo
Use this command to instruct the modem to echo characters sent to it. When
the echo feature is selected,
characters sent to the modem are sent back to the host and displayed on the
monitor.
Result codes:
_ OK if <value> = 0—1.
_ ERROR if <value>  0—1.
Command Function
E0 Disables echo command.
E1 Enables echo command (default).
B<value>—Communication Standard Setting
Use this command to select the communication standard used by the soft
modem.
Result codes:
_ OK if <value> = 0—3, 15, 16.
_ ERROR if <value>  0—3, 15, 16.
Command Function
B0
Selects CCITT V.22 mode when the modem is at 1200 bits/s.
B1 Selects Bell 212A when the modem is at 1200 bits/s (default).
B2 Deselects V.23 reverse channel (same as B3).
B3 Deselects V.23 reverse channel (same as B2).
B15 Selects V.21 when the modem is at 300 bits/s.
B16 Selects Bell 103J when the modem is at 300 bits/s (default).
C<value>—Carrier Control
This command is supported to ensure compatibility with communications
software that issues the C1 command.
However, this modem does not support the C0 command. The C0 command
instructs some modems not to send
carrier (i.e., it puts them in receive-only mode).
Result codes:
_ OK if <value> = 1.
_ ERROR if <value>  1.
Command Function
C1 Normal transmit carrier switching (default).
D<dial string>—Dial
This command instructs the soft modem to go off-hook and begin the dialing
sequence. The dial string (<dial
string>, including modifiers and the telephone number) is entered after the D
command.
A dial string can be up to sixty characters long. Any digit or symbol may be
dialed as touchtone digits. Characters
such as spaces, hyphens, and parentheses are ignored by the modem and
may be included in the dial string to
enhance readability.
I<value>—Request ID Information
Use this command to display product information about the modem. In each
case the information is transmitted to
the host system followed by a final result code.
Result codes:
_ As described in Table 8 if <value> = 0—9, 11.
_ ERROR if <value> 0—9, 11.
Command Function
L0 Low volume.
L1 Low volume.
L2 Medium volume (default).
L3 High volume.
H<value>—Hook Control
Instructs the modem to go on-hook to disconnect a call or go off-hook to make
the telephone line busy.
Result codes:
_ OK if <value> = 0—1.
_ ERROR if <value> 0—1.
Command Function
H0 The modem goes on-hook (default).
H1 The modem goes off-hook.
M<value>—Speaker Control
Use this command to turn the speaker on and off.
Result codes:
_ OK if <value> = 0—3.
_ ERROR if <value>  0—3.
Command Function
M0 Speaker is off.
M1 Speaker is on until the modem detects the carrier signal (default).
M2 Speaker is always on when the modem is off-hook.
M3 Speaker is on until the carrier is detected, except when dialing.
N<value>—Modulation Handshake
Use this command to set the modem protocol for handling handshake negotiation at
connection time if the communicationspeed of the remote modem is different from the
speed of the local modem.
Result codes:
_ OK if <value> = 0—1.
_ ERROR if <value>  0—1.
O<value>—Return to On-Line Data Mode
Use this command to exit on-line command mode and reenter on-line data
mode. If the modem is not in on-line
command mode when this command is received the modem generates an
ERROR result code.
Result codes:
_ CONNECT if <value> = 0, 1, 3 and the result code and call progress monitor
is set to 0 (X0).
_ CONNECT <rate> if <value> = 0, 1, 3 and the result code and call progress
monitor is not set to 0 (X<value>where n = 1—7).
_ NO CARRIER if the connection is not successfully resumed.
_ ERROR if <value>  0—1, 3.
Command Function
O0 Instructs the modem to exit on-line command mode
and return to data mode
O1 Issues a retrain before returning to on-line data mode.
O3 Issues a rate renegotiation before returning to on-line data mode.
P—Select Pulse Dialing
Use this command to configure the modem for pulse dialing. All subsequent
Commands
Commands
Commands
Commands
For more information, please go to www.hiroinc.com