25 02 2010

Quickly Referenced Commands

AT –  “Attention!

+++ –  “Escape Sequence

, –  “Pause

A/ –  “Repeat Sequence

ATA –  “Answer Mode

Bn –  “Select Communication Protocol

Cn –  “Transmission Carrier

Dn –  “Dial Control

En –  “Echo

Fn –  “Data Mode Echo

Hn –  “Hook Select

In –  “Report Modem Information

Ln –  “Set Speaker Volume

Mn –  “Set Speaker Mode

Nn –  “Automode Selection/Detection

On –  “Retrain Selection

P –  “Pulse Dialing

Qn –  “Result Codes to DTE

Sn=x –  “Status Registers

T –  “Tone Dialing

Vn –  “Format of Result Code

Wn –  “Extended Result Codes

Xn –  “Result Codes for Call Progress

Yn –  “Long Space Disconnect

Zn –  “Soft Reset and Restore

Verbosely Referenced Commands

AT –  “Attention!”  –  This command tells the modem that a command follows it.

+++ –  “Escape Sequence”  –  This command initiates an escape sequence to return the modem to the on-line command mode.

, –  “Pause”  –  The Comma normally initiates a 1-5 second pause, however is sometimes used as a command separator in +MS and other commands.

A/ –  “Repeat Sequence”  –  This repeats the previous command.  This command will not function properly if preceded by the AT command or followed by <CR>.

ATA –  “Answer Mode”  –  This command initiates the modem into an auto-answer mode.

Bn –  “Select Communication Protocol”  –  This command selects the v.22 or Bell 212A protocols for data calls.

B0 –  ITU-T v.22 (300bps or 1200bps)

B1 –  Bell 212A (300bps or 1200bps)

(There is sometimes a B2 that enables v.23)

Cn –  “Transmission Carrier”  –  This command controls the switching of the transmit carrier.

C0 –  Transmit carrier disabled

C1 –  Transmit carrier enabled

Dn –  “Dial Control”  –  This command dials the phone number with accordance to the modifiers of n.

DL –  Redial the last dialed number

DP –  Pulse dial

DR –  Enable answer mode

DS=x –  Dial the stored telephone number in x

DT –  Tone dial

DW –  Resume dialing after dial tone is detected

D, –  Pause before dial

D“555-4NET” –  Letters enclosed in quotes will be dialed as their corresponding numbers on the dialpad.

D! –  Enable “flash”.  (modem can go off hook for a specified amount of time before returning on hook)

D@ –  Modem will wait for a quiet answer before dialing the rest of the dial string

En –  “Echo”  –  This command controls whether the modem echos commands received by the DTE or not.

E0 –  Echo Disabled

E1 –  Echo Enabled

Fn –  “Data Mode Echo”  –  This command controls whether the modem echos commands sent while in data mode.

F0 –  Echo in data mode enabled

F1 –  Echo in data mode disabled

Hn –  “Hook Select”  –  This command determines whether the modem is on-hook (hangs up) or off-hook (picks up).

H0 –  On-hook

H1 –  Off-hook

In –  “Report Modem Information”  –  This command reports selected information about the modem.

I0 –  Modem model and speed

I1 –  ROM checksum

I2 –  Tests ROM checksum THEN reports it

I6 –  Data connection info

I7 –  Manufacturer and model info

Ln –  “Set Speaker Volume”  –  This command controls the speaker volume of the modem.

L0 –  Mute

L1 –  Low volume

L2 –  Medium volume

L3 –  High volume

Mn –  “Set Speaker Mode”

M0 –  Disable speaker

M1 –  Enable speaker until a carrier signal is detected

M2 –  Enable speaker

M3 –  Enable speaker after dialing but disable after a carrier signal is detected

Nn –  “Automode selection/detection”  –  This command is usually more basic (a simple N0 for disabled, N1 for enabled) on 56k modems where automode is more often controlled by an s-register or the +MS command.  The full basic Nn command is included for completeness.

N0 –  Disable automode

N1, N2, N3, N4, and N5 –  Enable automode.  Originate mode and Answer mode v.XX attempts will vary from register to register.  The N2-N5 commands will not normally be used by 56k modems.

On –  “Retrain Selection”  –  Confusing command that probably should never have been created as it uses an O rather than a 0 and can often be confused.  It enables or disables retraining.

O0 –  Retraining disabled in on-line command mode

O1 –  Retraining enabled in on-line command mode

P –  “Pulse Dialing”  –  This command sets the modem to pulse dial.  This command can be duplicated by DP.

Qn –  “Result Codes to DTE”  –  This command selects whether the modem sends result codes to the DTE or not.

Q0 –  Enable result codes to DTE

Q1 –  Disable result codes to DTE

Sn=x –  “Status Registers”  –  This command writes to or reads data from S-register n.  The data written is represented in the place of x.  The data used in read mode is selected by the value in x.  S-registers can vary a great deal, please consult the AT Command Set specific to your modem when attempting to use these.

T –  “Tone Dialing”  –  This command sets the modem to tone dial.  This command can be duplicated by DT.

Vn –  “Format of Result Code”  –  This command selects the format for information-text and result codes.

V0 –  Numeric format

V1 –  Word (verbose) format

Wn –  “Extended Result Codes”  –  This command enables selection of extended result codes.

W0 –  Enables the CONNECT result codes to report the DTE speed.

W1 –  Enables the CONNECT result codes to report the DTE speed.

W2 –  Enables the CONNECT result codes to report the DCE speed.

Xn –  “Result Codes for Call Progress”  –  This command selects tone detection and result code formatting options.

X0 –  Disable busy and dialtone detection.  Result codes 0-4 enabled.

X1 –  Disable busy and dialtone detection.  Result codes 0-5,10 enabled.

X2 –  Disable busy detection, enable dialtone detection.  Result codes 0-6,10 enabled.

X3 –  Enable busy detection, disable dialtone detection.  Result codes 0-5,7,10 enabled.

X4 –  Busy and dialtone detection enabled.  Result codes 0-7,10 enabled.

Yn –  “Long Space Disconnect”  –  This command tells the modem whether or not to disconnect if a 1.6 second break is detected.

Y0 – Long space disconnect disabled

Y1 –  Long space disconnect enabled

Zn –  “Soft Reset and Restore”  –  Restores modem profiles that are saved in non-volatile RAM.  Refers itself to the &W command.

Z –  Soft Reset, basic default restore

Z0 –  Restore setting 0

Z1 –  Restore setting 1



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