This Appendix details the "AT" commands used by modems and ISDN TAs. This information is provided to assist users who are using the serial port of LevelOne WBR-1100TX.
It is not relevant to Cable or DSL modems connected to the WAN (Ethernet) port.
For the LevelOne Wireless Broadband Router to use the Serial Port correctly, the modem or ISDN TA must be set as follows.
Setting |
AT Command |
Fixed baud rate setting
|
AT&B1
|
RTS/CTS flow control
|
AT&K3
|
DCD to track the presence of a carrier
|
AT&C1
|
DTR off to hang-up modem
|
AT&D2
|
DSR always on
|
AT&S0
|
If your Modem or ISDN TA uses the commands above, then the Initial String would be as follows:
AT&F&B1&K3&C1&D2&S0X4
Notes:
If your modem or ISDN TA is already working correctly using the PC's serial port, but you don’t know what the initialization string is, you can use the following procedure to find out.
Most modems use the standard AT commands, as shown in the following tables. Consult the manual for your modem to set what AT commands it supports.
Note that the trailing "n" in many commands indicates a number.
The
allowable numbers, and their effect, are listed below the command.
Command |
Description |
|
<any key>
|
Terminate current connection attempt
|
|
+++
|
Escape sequence code, entered in data state, wait for modem to return to
command state
|
|
ATA
|
Force answer mode on-line
|
|
ATBn
|
Handshake operation
|
|
|
B0
|
Select ITU-T V.22 for 1200 bps communication
|
|
B1
|
Select Bell 212A for 1200 bps communication
|
ATD
|
Dial number and options that follow
|
|
|
P
|
Pulse dial
|
|
T
|
Tone dial
|
|
,
|
Pause for a specified time
|
|
;
|
Return to command state after dialing
|
|
!
|
Hook flash, call transfer
|
|
W
|
Wait for second dial tone
|
|
@
|
Wait for 5-second silence before proceeding, otherwise return O
ANSWER"
|
|
R
|
Reverse Dial (Originate a call in answer mode)
|
ATDL
|
Dial last number
|
|
ATDSn
|
Dial number stored in NVRAM at position n. (n=0..9)
|
|
ATEn
|
Command mode local echo of keyboard commands
|
|
|
E0
|
Echo off
|
|
E1
|
Echo on
|
ATHn
|
On/Off hook control
|
|
|
H
|
Hang up modem
|
|
H0
|
Hang up (on hook), same as ATH
|
|
H1
|
Get off hook
|
ATIn
|
Display inquired information
|
|
|
I0
|
Display product code
|
|
I1
|
Display product information and ROM checksum
|
|
I2
|
Link status report
|
ATLn
|
Speaker volume control. n=0-7
|
|
ATMn
|
Speaker control
|
|
|
M0
|
Speaker always off
|
|
M1
|
Speaker on until carrier is detected
|
|
M2
|
Speaker always on
|
|
M3
|
Speaker on after last digit dialed, off at carrier detect
|
ATNn
|
Ring volume control, n=0 disables ring function. (n=0..7)
|
|
ATO
|
Return to on-line state
|
|
ATP
|
Pulse dial
|
|
ATQn
|
Result code displayed
|
|
|
Q0
|
Modem returns result code
|
|
Q1
|
Modem does not return result code
|
|
Q2
|
Return result code but quiet in answer mode (will not show in
AT&Vn)
|
ATS0=n
|
Number of rings required before modem answers. n=0 disables auto-answer.
|
|
ATSr.b=n
|
Set bit b of S-register r to n. (n=0 or
1)
|
|
ATSr.b?
|
Inquiry bit b of S-register r
|
|
ATSr=n
|
Set S-register r to value n, where n is a decimal
number between 0-255
|
|
ATSr?
|
Display value stored in S-register r
|
|
ATT
|
Tone dial
|
|
ATVn
|
Verbal/Numeric result codes
|
|
|
V0
|
Display result codes in numeric form
|
|
V1
|
Display result codes in verbose form
|
ATXn
|
Result code options. (n=0..7)
|
|
ATZn
|
Reset the modem and set power-on profile. (n=0..4)
|
|
|
Zn
|
Reset modem and load user profile n (n=0..3)
|
|
Z4
|
Reset modem and load factory settings
|
AT$
|
Help, Basic command summary
|
|
AT&$
|
Help, Extended AT& command summary
|
|
AT*$
|
Help, Extended AT* command summary
|
(Includes RTS/CTS Flow Control Commands)
Command |
Description |
|
&Bn
|
Data rate, terminal-to-modem
|
|
|
&B1
|
DTE/DCE rate fixed at DTE setting
|
&Cn
|
Carrier Detect operations
|
|
|
&C1
|
Carrier Detect tracks presence of carrier
|
&Dn
|
Data Terminal Ready (DTR) operations
|
|
|
&D2
|
DTR off causes modem to hang up
|
&F
|
Load the default factory settings,
|
|
&Kn
|
Data flow control, DTE/DCE, n=0,3,4
|
|
|
&K0
|
Flow control disabled
|
|
&K3
|
Hardware (RTS/CTS) flow control
|
|
&K4
|
Software (XON/XOFF) flow control
|
&Sn
|
Data Set Ready (DSR)
|
|
|
&S0
|
DSR overridden, DSR always on
|