Hayes at Commands

7/29/2019 Hayes at Commands

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01/ 13 Hayes AT Commands

1/23me.intekom.com/opti on/hayesat.htm

The Hayes AT command setis the industry standard method of

communicating with and setting up a modem. These represent

commands for the Rockwell chipsets.

Syntax rules

Hayes AT Commands Listing

SMS commands

AT Command Result Codes

Country Settings

S Registers

Syntax Rules

A command string should start with "AT" or "at", except for the commands "A/" and "+++".

At or aT are invalid.

Several commands can be given in one command string.

The commands can be given in upper or lower case.

A command string should contain less than 40 characters.

When an error is made during the typing of the command, it can be corrected using the

backspace key.

Commands and command strings must be terminated with an , except +++ and A/

A telephone number can exist of following characters:

1 2 3 4 5 6 7 8 9 * = , ; # + > . All other characters are ignored (space, underscore ). They

help formatting the dialstring.

Commands that use a numerical parameter, can be used without a numerical value. In this

case the command will be issued with the value zero.

If the command string contains two consecutive commands without parameter, as discussed

above, the modem will respond with an error.

After the command ATZ has been issued, a pause of two seconds should be respected

before entering the next commands.

IMPORTANT: The commands below are standard Hayes AT commands, and will work with the

Option 2-in-1 modem. Some vendors implement their own AT commands which will only work

with their brand/model of modem.

Hayes AT Commands

AT or at always precedes a command. The modem needs these two letters to adjust itself to the

settings of the PCs comport. The modem then switches automatically to the defined baud rate
http://home.intekom.com/option/hayesat.htm#S-Registershttp://home.intekom.com/option/hayesat.htm#Supported%20countrieshttp://home.intekom.com/option/hayesat.htm#AT%20Command%20Result%20Codeshttp://home.intekom.com/option/hayesat.htm#Hayes%20AT%20Commandshttp://home.intekom.com/option/hayesat.htm#S-Registershttp://home.intekom.com/option/hayesat.htm#Supported%20countrieshttp://home.intekom.com/option/hayesat.htm#AT%20Command%20Result%20Codeshttp://home.intekom.com/option/faq59.htmhttp://home.intekom.com/option/hayesat.htm#Hayes%20AT%20Commandshttp://home.intekom.com/option/hayesat.htm#Syntax%20Rules


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and parity, until the next command is issued or the modem is turned off. The modem will not

respond to any commands not preceded by an AT.

The modem recognises following formats :

1 or 0 start bits, 7 or 8 data bits, no, odd or even parity and 1 or 2 stop bits.

The commands can be issued at a rate between 300 and 115,000bps. In V.23 mode, the

commands are sent at 1,200bps. The modems replies are then sent at 75bps to the PC.

The command interpreter recognizes AT and at, but not At or aT. Both characters have to be

sent in upper- or lowercase and must be sent directly after one another.

+++ Switch from data mode to command mode without dropping the line. A second

before and after this command, no other character may be sent to the modem, including

a .

A/Repeat last command, no

ATAAnswer incoming call

When you want to answer a call manually, you type this command after a ring has appeared on

the sc reen of your Terminal emulator.

DDial a telephone number

ATDTn After issuing this command, the modem will attempt to establish a connection and dial the

number n.

Options to the command D:

W Wait for dialtone. When using a PABX this is used to wait for the second dialtone.

Note: not all PABXs give a second dialing tone. Consider using "@" instead.

@ Wait for silence for 5 seconds.

, Pause for 2 seconds (S8)

! Flash ( on-hook for value in S29 )

; Return to command mode after dialing.

P Pulse dial


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T Tone dial

n The telephone number to be dialed

Sn Dial number stored in directory entry &Zn where n=0..19. The selected number is shown

on the screen for verification.

J Perform MNP10 link negotiation at highest supported speed (for this call only).

L Redial last number.

^ Disable calling tone, this call only.

The call can be aborted at any stage before the connect message appears, by entering any

character except Linefeed.

ATECommand echo to host

E0 Commands are not echoed

E1 Commands are echoed

With this command you can select if the modem should return all the commands to the screen or

not. This is useful to check if all characters are received by the modem. If characters appear

double on the screen, disable echoing by the modem or by your terminal. The value of ATE can be

written in the RAM of the modem using AT&W.

ATFnSelect transmission mode/speed

F0 Auto mode

F1 V.21 300bps

F3 V.23 75Tx/1200Rx with AT%F1

V.23 1200Tx/75Rx with AT%F2

F4 V.22 1,200bps

F5 V.22bis 2,400bps

F6 V.32bis 4,800bps

F7 V.32bis 7,200bps

F8 V.32bis 9,600bps

F9 V.32bis 12,000bps

F10 V.32bis 14,400bps


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These commands are not valid for V.34 modems. The equivalent command for the V.34 modems is

+MS, please refer to this command.

ATHGo on-hook, hang up.

H0 Go on-hook ( Hang up )

H1 Go off-hook

ATIIdentifiers

I0 Product code

I1 Pre-computed Checksum

I2 Returns OK

I3 Returns OK

I4 OEM String

I5 - I11 Returns OK

I12 ROM Checksum

I13 RC Version number

I14 Shows Firmware version

I15 Shows selected country

I17 GSM option

I18 Shows Supported GSM Kit (GSM-ready only)

ATLSpeaker volume settings

L0 Lowest speaker volume

L1 Low speaker volume

L2 Medium speaker volume

L3 Highest speaker volume


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With this command the speaker volume can be set.

ATMSpeaker control

M0 Speaker always off

M1 Speaker on until carrier detected

M2 Speaker always on

M3 Speaker on only while answering

ATNnSelect Auto mode

N0 Auto mode disabled

N1 Auto mode enabled

This command is not longer valid for the V.34 modems.

ATOnReturn to data mode

O0 Return to data mode from command mode, only if on-line.

O1 Return on-line and initiate retrain (2400bps or higher)

ATQnResult codes

Q0 Modem returns result codes

Q1 Quiet mode enabled. Modem gives no result codes.

If the quiet mode is enabled, the responses from the modem are not sent to the PC.


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ATSnSets and reads the selected register

Sn=x Sets register n to the value x

Sn? Reads the value of register n

n is a numeric value, varying between 0 and 255 (depending on the register).

ATVnResult codes in numerical or verbose form

V0 Returns the code in numerical form

V1 Full-word result codes

ATWnConnect messages formatting

W0 DTE rate ( connect rate )

W1 Hayes 4 line format : Carrier, Protocol, Compression, DTE rate

W2 Result code is DCE rate ( carrier rate )

ATXnExtended Result codes

X1 Ignore dialtone and busy tone

X2 Ignore busy tone

X3 Inner dialtone

X4 Modem recognises dialtone and busy tone

X3 and X1 set the modem for Blind Dialing. This option is country specific, because some countries

do not allow blind dialing.

ATYnLong Space disconnect


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Y0 Disable long space disconnect

Y1 Enable long space disconnect

If the modems receives after activating this function, a BREAK-signal of at least 1.6 seconds

coming from the remote PC, it will send a BREAK-signal of 4 seconds back to the remote PC before

hanging up the telephone line.

ATZnResetting the modem

Z0 Restore stored profile 0

Z1 Restore stored profile 1

If this command is issued to the modem during a connection, the modem will drop the line.

According to the parameter n, the modem will restore the values stored in the non-volatile RAM

(See also &W ).

AT&CnCarrier-detect

&C0 DCD is always active

&C1 DCD is active if modem is on-line

Data Carrier Detect (DCD) is a hardware signal that notifies the software that the modem is in

communication with another modem. Most softwares will not start-up properly if the DCD is

active. Default is &C1.

AT&DnData Terminal Ready settings

&D0 Modem ignores DTR

&D1 Go to command mode on ON-to-OFF DTR transition.

&D2 Hang up on DTR-drop and go to command mode

&D3 Reset (ATZ) on DTR-drop. Modem hangs up.


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AT&FRestore Factory Settings

&F0 Use profile 0

&F1 Use profile 1

The modem is reset to the default firmware settings. If the modem is on-line, the command will

not be executed.

AT&GnSelect guard tone

&G0 Disables guard tone

&G1 Disables guard tone

&G2 Selects 1800Hz guard tone

This command may not be permitted in some countries.

AT&KnFlow Control

&K0 Flow control disabled

&K3 RTS/CTS flow control (Hardware)

&K4 XON/XOFF flow control (Software)

&K5 Transparent XON/XOFF flow control

&K6 RTS/CTS and XON/XOFF flow control

Flow control is the use of characters or RS232 signals to start and stop the flow of data to avoid

data loss during buffering. This is extremely important when the DTE/DCE rate is different from the

line speed, e.g. when data compression is used. The DTE/DCE rate must be higher then the line

speed.

RTS/CTS flow control (Hardware flow control)

The PC will send data to the modem. The modem will store this data in a buffer. When this buffer

is full, the modem will drop the CTS-line, telling the PC that it has to stop transmitting data until


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the signal raises again. If the RTS-signal is OFF, transmitting data to the PC is stopped until the

signal switches to ON.

XON/XOFF flow control (Software flow control)

If the modem receives a XON-character (S32) from the PC, it stops transmitting data to the PC

until it receives a XOFF-character (S33). The process is similar if the PC is sending data to the

modem.

NOTE : The preferable setting is RTS/CTS flow control

AT&PnPulse dial make-break

&P0 : 61/39 ratio at 10pps




Settings may be locked depending on country selection. Default is also country dependent.

AT&QnSync/Async Mode

&Q0 : Selects direct async operation.

&Q1 : Selects synchronous connect mode with async off-line command mode.

&Q2 : Selects synchronous connect mode with async off-line command mode and enables DTRdialing.

&Q4 : Selects Autosync mode

&Q5 : The modem will try to negotiate an error corrected link.

&Q6 : Selects async operation in normal mode.

This command is used to control the connection modes permitted.

AT&RnCTS/RTS option


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&R0 : In sync mode, CTS tracks the state of RTS. In async mode, CTS acts according V.25bis

handshake.

&R1 : In sync mode CTS is always on. In async mode, CTS will drop only if required by flow

control.

This selects how the modem controls CTS. CTS operation is modified if hardware FC is selected (

AT&Kn ).

AT&SnDSR Override

&S0 : DSR will remain on at all times.

&S1 : DSR will become active after answer tone has been detected and inactive after the carrier

has been lost.

This command selects how the modem will control DSR.

AT&TnTest and diagnostics

&T0 : Terminates test

&T1 : Initiates local analogue loop back

&T2 : Returns ERROR

&T3 : Initiates local digital loop back

&T4 : Enables digital loop back acknowledgment for remote request.

&T5 : Disables digital loop back acknowledgment for remote request.

&T6 : Requests a remote digital loop back without self test.

&T7 : Requests a remote digital loop back with self test

&T8 : Initiates local analogue loop back with self test.

The modem will perform selected test and diagnostic functions according to the parameter

supplied. A test can be run only when in an asynchronous operation in non-error-correction mode.

To terminate a test in progress, the escape sequence must be entered first, except forparameters 7 and 8.

AT&Vn Display current configuration and stored profiles


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Reports the current (active) configuration, the stored (user) profiles, and the first four stored

telephone numbers.

AT&WnStore current configuration

&W0 : Store current configuration in profile 0

&W1 : Store current configuration in profile 1

AT&XnSelect Synchronous Clock Source

&X0 : Selects internal timing

&X1 : Selects external timing

&X2 : Selects slave receive timing

Selects the source of the transmit c lock for the synchronous mode of operation.

AT&YnDesignate a default reset profile

&Y0 : The modem will use profile 0

&Y1 : The modem will use profile 1

Selects which user profile will be used after a hard reset.

AT&ZnStore telephone number

&Zn=x n=0 to 3 and x=dial string

AT%EnLQM and Auto-retrain or FB/FF


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%E0 : Disable Line Quality Monitor and auto-retrain

%E1 : Enable Line Quality Monitor and auto-retrain

%E2 : Enable Line Quality Monitor and fall back/fall forward. (V.34 only)

Controls whether or not the modem will automatically monitor the line quality and request a retrain

or fall back / fall forward depending on the line quality.

AT%CnEnable/Disable data compression

%C0 : Disables data compression

%C1 : Enables MNP5

%C2 : Enables V.42bis

%C3 : Enables both V.42bis and MNP5 data compression.

Enables or disables data compression negotiation. The modem can only perform data compression

on an error corrected link.

AT\GnModem to modem flow control

\G0 : Disables modem-to-modem flow control

\G1 : Enables modem-to-modem flow control

In non-error correction mode, the modem enables or disables the generation or recognition of

modem to modem XON/XOFF flow control according to the parameter supplied. In error correctionmode, the setting of \G is ignored.

AT\NnOperating mode

\N0 : Normal speed buffered mode. (&Q6)

\N1 : Serial interface selected. (&Q0)

\N2 : Reliable connection ( First V.42 the MNP4). Failure to make a reliable connection results in

modem hanging up.

\N3 : Auto reliable mode ( First V.42, then MNP4 then speed buffered )


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\N4 : V.42 (LAPM) . If connection fails, modem hangs up.

\N5 : MNP4 EC mode. Failure results in hanging up.

This command controls the preferred error correcting mode to be negotiated in a subsequent data

connection.

\AnSelect maximum MNP block size

\A0 64 characters

\A1 128 characters

\A2 192 characters

\A3 256 characters

)MnEnable cellular power level adjustment

)M0 : Disables transmit power level adjustment during MNP10 link negotiation.

)M1 : Enables transmit power level adjustment during MNP10 link negotiation. V.34 : Uses the@Mn value to establish initial cellular connection. After connection power level is determined by

modem.

)M2 : Enables transmit power level adjustment during MNP10 link negotiation. Uses the @Mn value

to establish initial cellular connection. After connection power level is fixed. (V.34 only)

Enables or disables automatic adjustment of the transmit power level to accommodate the

signaling requirements of cellular telephone equipment.

-KnMNP Extended Services

-K0 Disables V.42 LAPM to MNP10 conversion

-K1 Enables V.42 LAPM to MNP10 conversion

-K2 Enables V.42 LAPM to MNP10 conversion, inhibits MNP ES initiation during V.42 LAPM

answering mode detection Phase (V.34 only)

Enables or disables conversion of a V.42 connection to a MNP10 connection.


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V.34 Commands

Following commands are valid only for the V.34 modems.

@MnInitial Cellular Power Level set ting

@M0 -26dBm (Default)

@M1 -30dBm

@M2 -10dBm

@M3-@M10 -10dBm

@M11 -11dBm

...

@M31 -31dBm

Sets the initial power level for up shift at connect until line conditions can be determined.

:EnCompromise Equalizer Enable command

:E0 Disables the equalizer

:E1 Enables the equalizer

Enables or disables the V.32 compromise equalizer. This command can be used when the modem is

attached to either a flat line or a cellular connect ion.

+MSSelect Modulation

Note : The use of the Nn command is not recommended for speeds higher than 14.400.

Syntax:

+MS=[,[][,[][,[max_rate>]]]]


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+MS? Reports selected options

response : +MS:11,1,300,33600 (example)

+MS=? Reports supported options

response : +MS:(0,1,2,3,8,9,10,13,64,69,74),(0,1),(300-33600),(300-33600)

Sub parameter definitions:

1. Mod

Modulation Bps

0 V.21 300

1 V.22 1200

2 V.22bis 2400 or 1200

3 V.23 1200/75

9 V.32 9600,4800

10 V.32bis 14400,9600,7200,

4800,1200

11 V.34 33600,32100,28800,

26400,24000, 21600,

19200, 16800,

14400,9600,7200, 4800,

2400

64 Bell 103 300

69 Bell 212 1200

74 V.FC 28800,26400,24000,21600,

19200, 16800,

14400,9600,7200,4800,2400

2. is an optional numeric value which enables or disables automatic modulation

negotiation using V.8 or V.32bis Annex A. The options are :

0 Auto mode disabled


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1 Auto mode enabled using V.8 or V.32bis Annex A

The default value is 1, which enables auto mode. Note, however, there are modulations for which

there is no automatic negotiation, e.g., Bell 212.

=1

The modem connects at the highest possible rate in accordance with V.8 or V.32bis Annex A if

V.8 is not supported by the remote modem.

A. If is greater than the highest speed supported by then modulation specified by

, the modem auto modes down from the highest rate to the selected modulation. For

example : +MS=10,1,1200,24000 selects auto moding down from V.32bis 14400bps.

B. To emulate issuance of the N1 command, specify the modulation and the rate to start auto

moding down from using and , respectively. Examples :

+MS=11,1,300,16800 auto mode at V.34 16800bps

+MS=9,1,300,12000 auto mode at V.32bis 12000bps

3. is an optional number which specifies the lowest rate at which the modem may

establish a connection. The value is decimal coded, in units of BPS, e.g. 2400 specifies the lowest

rate to be 2400. The default is 300 for 300bps.

3. is an optional number which specifies the highest rate at which the modem may

establish a connection. The value is decimal coded, in units of BPS, e.g. 14400 specifies the

lowest rate to be 14400. The default is 33,600 for 33,600bps.

AT Command Result Codes

The modem responds to commands from the DTE ( PC ) and to activity on the line by signaling to

the DTE in the form of result codes. The result codes that the modem can send are described

below.

Value Verbose

0 OK


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1 RING

3 NO CARRIER

4 ERROR

5 CONNECT 1200

6 NO DIALTONE

7 BUSY

8 NO ANSWER

9 CONNECT 0600

10 CONNECT 2400

11 CONNECT 4800

12 CONNECT 9600

13 CONNECT 7200

14 CONNECT 12000

15 CONNECT 14400

16 CONNECT 19200

17 CONNECT 38400

18 CONNECT 57600

19 CONNECT 115200

22 CONNECT 75TX/1200RX

23 CONNECT 1200TX/75RX

24 DELAYED

32 BLACKLISTED

33 FAX

35 DATA

40 CARRIER 300

44 CARRIER 1200/75

45 CARRIER 75/1200

46 CARRIER 1200

47 CARRIER 2400

48 CARRIER 4800

49 CARRIER 7200


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50 CARRIER 9600

51 CARRIER 12000

52 CARRIER 14400

53 CARRIER 16800

54 CARRIER 19200

55 CARRIER 21600

56 CARRIER 24000

57 CARRIER 26400

58 CARRIER 28800

59 CARRIER 31200

60 CARRIER 33600

61 CONNECT 16800

62 CONNECT 21600

63 CONNECT 24000

64 CONNECT 26400

65 CONNECT 28800

66 CONNECT 33600

67 COMPRESSION: CLASS 5

68 COMPRESSION: V.42 bis

69 COMPRESSION: NONE

70 PROTOCOL: NONE

77 PROTOCOL: LAPM

80 PROTOCOL: ALT

81 PROTOCOL: ALT-CELLULAR

+F4 +FCERROR

Supported countries


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To change the country settings, use followingfollow next procedure :

AT*NCnn

Modem responds with OK

ATZ

Modem responds with OK

Note : Some counties do not allow their country settings to be altered.

*NCnnCountry select

40 Australia

1 Austria

2 Belgium

3 Denmark

4 Finland

5 France

6 Germany

17 Greece

10 Netherlands

7 Ireland

8 Italy

43 Japan

26 Namibia

11 Norway

12 Portugal

27 South Africa

13 Spain

14 Sweden

15 Switzerland


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16 UK

19 Czech Republic

24 Poland

25 Russia

22 United States

Note : Use the Interactive Manual to setup the country.

S-Registers

S0Auto-answer

Sets the number of the rings required before the modem automatically answers a call.

Setting this register to zero disables auto-answer mode

Range : 0 to 255

S1Ring counter

S1 is incremented each time the modem detects a ring signal on the telephone line.

Range : 0 to 255

S2Escape character

S2 holds the decimal value of the ASCII character used as the escape sequence. A value

over 127 disables the escape process.

Range : 0 to 127 (Default = 43)

S3Carriage Return Character

Sets the command line and result code terminator character. Pertains to asynchronous

operation only.

Range : 0 to 127 ASCII decimal (Default=13)

S4Line feed Character

Sets the character recognised as a line feed. Pertains to asynchronous operation only.


S5Backspace Character

Sets the character recognised as a backspace.


S6Wait for dialtone


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Sets the time in seconds that the modem will try to detect a dialtone (if set) and wait

before starting to dial.

Range : 2 to 255 seconds

S7Wait for Carrier after dial

Sets the time in seconds that the modem will wait for a carrier before hanging up.


S8Pause time for delay

Sets the time the modem must pause when the , dial modifier is used.


S9Carrier detec t response t ime

Sets the time in 10th of a second, that the carrier must be present before the modem

considers it valid and turns on RLSD.

Range : 1 to 255 tenths of a second.

S10Lost carrier to Hang-up delay

Sets the time in 10th of a second, that the modem waits before hanging up after a loss of

carrier.

Range : 1 to 255

S11DTMF Tone duration

Range : 50 to 255 milliseconds (Default=95)

S12Escape Prompt Delay

Defines the maximum period, in fifties of a second, allowed between receipt of the last

character of the three escape character sequence and the sending of the OK message.

Range : 0 to 255 1/50 of a second

S18Test timer

Sets the length in seconds that the modem conducts a test.


S25Delay to DTR

Sets the time that the modem will ignore DTR before taking action specified by &Dn.


S26RTS to CTS delay

Sets the time delay, before the modem turns on CTS after detecting an OFF-ON transition

on RTS when &R0 is commanded.

Range : 0 to 255 hundredths of a second


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S32XON Character


S33XOFF Character


S38Delay Before Forced Hang-up

This register sets the delay between the modems receipt of the H command to disconnect

and the disconnect operation.


S86Call Failure Reason Code

When the modem issues a NO CARRIER result code, a value is written to this S-register.

Range : 0,4,5,9,12,13 or 14

0 Normal disconnect, no error occurred

4 Loss of carrier

5 V.42 negotiation failed

9 The modems could not find a common protocol

12 Normal disconnect initiated by the remote modem

13 Remote modem does not respond after 10 re-transmissions of the same message.

14 Protocol violation

S91PSTN Transmit level Attenuation

Sets the transmit level attenuation level from 0 to 15dBm for the PSTN mode. Some

countries may not permit changing the transmit level.

Range : 0 to 15dBm (Corresponding to 0 to -15dBm transmit level)

Default : 10dBm

S95 Extended Result Codes

The bits in this register can be set to override some of the Wn command options. A bit

set to a 1 in this register will enable the corresponding result code regardless of the Wn

setting.

Bit 0 Connect message indicates DCE speed

Bit 1 Append /ARQ to CONNECT XXXX

Bit 2 Enable CARRIER XXXX message

Bit 3 Enable PROTOCOL message

Bit 4 Reserved

Bit 5 Enable COMPRESSION XXXX


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Bit 6 Reserved

Bit 7 Reserved

DisclaimerAll trademarks or product names mentioned herein are the property of their respective owners.

Specifications subject to change without notice. E&OE.This page serves m erely as an informa tional aid &, unless stated, does no t imply any endoresme nt of or by the

parties mentioned within.Copyright 1997/1998

Hayes at Commands

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Transcript of Hayes at Commands