Chapter 4

AT Commands

This chapter describes the basic modem commands in alphabetical order. Some commands have factory default settings, for which you can refer to your Getting Started manual Command Summary table.

4.1Prefix, Repeat and Escape Commands

AT Attention. Precede all command lines except A/ and +++

A/ Re-execute the last command in command buffer

+++Escape characters, requires guard time before and after

4.2Dial Commands and Dial Modifiers

DOriginate a call

S=n Dial the nth stored number

TTouch tone dialing P Pulse dialing

R Dial in answer mode

WWait for second dial tone L Re-Dial the last valid

telephone number

,Pause ! Flash

; Return to command state

4.3Operation Commands

A

Answer incoming call

 

M2

detected

B0

CCITT or ITU-T compatibility

 

Speaker always on

 

N0

Fixed data rate follow *N

B1

Bell protocol only

 

 

 

 

 

command

E0

Disable command echo

 

 

 

N1

Enable adaptive data rate

E1

Enable echo command

 

 

O0

Return to data-link without

 

characters

 

 

 

 

 

retrain

H0

Hang up the connection (on-

 

O1

 

Return to data-link with

 

hook)

 

H1

 

 

retrain

Go off-hook to make a call

 

 

 

Q0

Modem sends response

I0

Reports product code

 

 

 

codes

I1

Calculates the ROM

 

Q1

 

Do not send response codes

 

checksum

 

I3

 

Sr?

Display the value in register

Reports firmware version

 

 

 

 

Sr=n

Set register r to a value n

 

L0

Low volume

 

V0

Display response codes in

L1

Low volume

 

L2

Medium volume

 

 

digit form

L3

High volume

 

V1

Display response codes in

 

 

 

 

words

 

M0

Speaker off at all times

 

 

 

W0

Disable V.42 response codes,

M1

Speaker on until CD

 

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Advantech PCM-3601 AT Commands, Prefix, Repeat and Escape Commands, Dial Commands and Dial Modifiers, Operation Commands