AT Commands


This section introduces the AT commands available in Hayes modems. The section provides a general introduction to the AT command structure and then presents an alphabetical listing of the commands.

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For information about a specific command, click on a command from the following list:

A - Answer Command

Bn - Communications Options


D - Dial Command

En - Select Echo

Hn - Control Switchhook

I0 - Display Product Code

I2 - Perform ROM Checksum Test

I7 - Version Number

I9 - Identify Plug and Play ID

I12 - Display GCP version strings

Ln - Select Speaker Volume

Mn - Select Speaker Function

Nn - Select Negotiate Handshake

On - Go Online

P - Select Pulse Dial

Qn - Select Result Code

Sn - Write to S register

Sn? - Read an S register

T - Select Tone Dialing

Vn - Result Code Format

Wn - Extended Result Code

Xn - Call Progress

Yn - Long Space Disconnect

Zn - Perform Soft Reset

&An - Originate/Answer for Autoanswer

&B - Disable Auto Retrain

&Cn - Data Carrier Detect

&D - Data Terminal Ready

&F - Factory Defaults

&Gn - Guard Tone

&Jn - Jack Type

&Kn - Flow Control

&Ln - Line Type

&On - Pad Channel

&Pn - Pulse Dial Parameters

&Qn - Communications Mode

&Rn - RTS/CTS Option

&Sn - Data Set Ready

&T0 - Terminate Test

&T1 - Local Analog Loopback

&T3 - Local Digital Loopback

&T4 - Grant RDL Requests

&T5 - Deny RDL Requests

&T6 - Initiate Remote Digital Loopback

&T7 - RDL with Self Test

&T8 - Local Loopback/Self Test

&T19 - RTS/CTS Cable Test

&Un - Disable Trellis Coding

&V - View Configuration Profiles

&V6 - View Blacklist

&V8 - View Call Statistics

&Wn - Store Active Profile

&Xn - Sync Xmit Clock Source

&Yn - Stored Profile for Hard Reset

&Zn=- Stored Telephone Number

&Hn= - Help Menu Commands

%CD - Carrier Detect Lamp

%BAUD - Bit Rate Multiplier

-SSE - Simultaneous Voice Data

-SSG - Set DSVD Receive Gain

-SSP - Select DVSD Port

,comma- Perform Pause

%SPRT Security Mode - Outgoing Calls

%SUID - User ID Outgoing Calls

%SPWD - Password Outgoing Calls

%SSPW - Supervisor Password Outgoing Calls

%SCBR - Call Back Reference Outgoing Calls

%SKEY - Store Authentication Key Outgoing Call

-SUID - Program User ID

-SPWD - Program Password

-SPRT - Remote Security Mode

-SKEY - Program Key

-SSPW - Supervisor Password

-SSKY - Program Supervisor Key

$BRC - Enable/Disable Host

$GIVEBRC - Enter BRC State (from Target Online Command State)

_+BRC+_ Remote Escape into BRC State (from Host Online Data Mode)

%CCID - Enable Caller ID

%CRID - Repeat Last ID

+VCID - Caller ID Service

#CID - Enable Caller ID Detection

%CXID - XID Enable

%CDIA - Display last DIAG

%CIDS - Store ID Numbers

%CSIG - Store SIG Numbers

%SPNP - Serial Plug and Play Control
About Commands

With a few exceptions, command names contain a prefix (optional), a letter, and a suffix (optional).
Prefix  &, %, etc.                                                                                          


Letter  A, B, etc.                                                                                             


Suffix  a number, such as 5                                                                                    
Following are several examples:

Example: &K5 prefix = &
letter = K

suffix = 5

Example: D letter only

Example: I0 letter and suffix

In the command descriptions, the suffix is represented generally by the letter n. Do not insert spaces in command names. The modem ignores spaces between commands.

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