[ AT Command Set For The PC-TEL Reference Design ]
AT Command Set For The PC-TEL Reference Design. |
Disclaimer: Since manufacturers who use our chips can modify portions of the drivers, these may not be accurate for your modem! If these do not match your modem, contact the manufacturer. |
AT Commands | Ampersand Commands | Percent Commands | Backlash Commands | Asterisk Commands
Command |
Description |
AT |
Attention - this precedes all commands except A/ |
/A |
Execute previous command - does not require a <CR> * |
A |
Causes the modem to go off hook. If a call is coming in, the modem will try to answer it. The procedure for answering a call is a short silence and then an answer tone. Sending a character to the modem during this procedure will abort the answer procedure. The amount of time the modem will wait for a carrier is programmable by modifying the S7 register. |
B0 |
Select CCITT V.22 (1200 bps) Select Bell 212A (1200 bps) Select CCITT V23 Originate mode will transmit data at 75 bps and receive data at 1200 bps. Answer mode will transmit data at 1200bps and receive data at 75bps. The command N0 (Disable auto mode) must be selected. |
D |
D alone will take the modem off-hook and wait for a dial tone. (See X command for exceptions) The length of time to wait for a dialtone before dialing is programmable in register S6. |
Dmn |
ATDmn will dial a phone number where m is a
modifier: L, W, ,, ;, @, !, or S. It will dial the telephone number n. Dial last number Wait for dial tone. If you have selected X0 or X1 (disable dial tone detection), then you can use this modifier to override that setting. Pause during dial. The amount of time to pause is determined in register S8. Return to command mode after dialing. It doesn't wait for carrier or hang up. Wait for 5 seconds of silence. This is used to access systems that do not provide a dial tone. Hook flash. Causes the modem to go on-hook for 0.5 seconds. This is used in PBX systems and for voice features like call waiting. Dials a stored number. Up to ten numbers can be stored, and the addresses are from 0 to 9. To store a number into one of these addresses, use the &Z command. |
E0 |
Commands
issued to the modem are not echoed to the local terminal. This only matters in the command
mode. It does not affect the modems ability to send response codes. Commands are echoed to the local terminal. |
H0 |
Force
modem on-hook (hang-up). Force modem off-hook (to answer or dial). |
I0 |
Return
numeric product code Return hardware variation code Report internal code Report software revision number Report product feature listing |
L0 |
Speaker
volume zero Speaker volume low Speaker volume low Speaker volume low (Hardware currently limits volume adjustment to on/off) |
M0 |
Speaker
always off Speaker on until carrier detected Speaker always on Speaker on during answering only |
N0 |
Disable
auto-mode. This forces the modem to connect at the speed specified in register S37. Enable auto-mode. The modem will answer at the highest available line speed and ignore any ATBn command. |
O0 |
Return to data mode. If you have entered the
command mode using the time independent escape sequence, this will put you back in data
mode without going on-hook. Retrain the modem. If the line condition has changed since the original connection, retraining the modem will cause it to reconnect at the most efficient speed for the current line condition. |
P |
Pulse dialing allows the modem to work on telephone networks where tone is not supported. Pulse and Tone dialing can not be mixed on the same command line. |
Q0 |
Enable
response to DTE. Disable response to DTE. The modem does not respond to the terminal. Issuing a command will not produce a response (unless the command is something like ATZ, which will restore this setting to default.) |
Sn |
Set
default S-register. Any subsequent = or ? commands will modify the default S register. Set register n to value m Return the value of register n |
T |
Tone
dialing Pulse and Tone dialing can not be mixed on the same command line. |
V0 |
Result
codes will be sent in numeric form. (See the result code table) Result codes will be sent in word form. (See the result code table.) |
W0 |
Report
DTE speed only. After connection, there will be no message about what Error
Correction or Data Compression protocol is in use. Report DCE speed, Error Correction/Data Compression protocol, and DTE speed. Report DCE speed only |
X0 |
Send OK, CONNECT, RING, NO CARRIER, ERROR and
NO ANSWER. Busy and Dial Tone Detection are disabled. Send X0 messages and CONNECT speed Send X1 message and NO DIALTONE Send X2 messages and BUSY and RING BACK. Dial Tone Detection is disabled. Send all responses |
Y0 |
Disable
long space disconnect Enable long space disconnect With error correction: hang up after sending 1.6 second long space Without error correction: hang up after 4 second long space |
Z0 |
Reset
modem to profile 0 Reset modem to profile 1 |
=n |
Sets the value of the default S register |
? |
Reports the value stored in the default S register. |
Advanced Commands |
&C0 |
Force
DCD on DCD follows remote carrier |
&D0 |
DTR is assumed on DTR drop causes modem back to command mode without disconnecting DTR drop causes modem to hang up DTR drop causes modem to be initialized; &Y determines which profile is loaded. |
&F |
Load factory profile |
&G0 |
Disable
guard tone Enable 550Hz guard tone Enable 1800Hz guard tone on answering modem |
&K0 |
Disable flow control Enable RTS/CTS flow control Enable XON/XOFF flow control Enable transparent software flow control Enable both RTS/CTS and XON/XOFF flow control |
&P0 |
Selects
39%-61% make/break ratio at 10 pulses per second Selects 33%-67% make/break ratio at 10 pulses per second Selects 39%-61% make/break ratio at 20 pulses per second Selects 33%-67% make/break ratio at 20 pulses per second |
&S0 |
Force
DSR on DSR on at the start of handshaking and off after carrier loss |
&T0 |
Terminate
test Start ALB test |
&U0 |
Enable
trellis coding Disable trellis coding |
&V0 |
Display
active profile Display stored profiles Display stored telephone numbers |
&W0 |
Save
active profile to profile 0 Save active profile to profile 1 |
&Y0 |
Use
profile 0 on powerup Use profile 1 on powerup |
&Zn=m |
Save telephone number (up to 36 digits) into memory location n (0-9) |
%C0 |
Disable
data compression Enable MNP5 compression Enable V.42bis compression Enable both V.42bis and MNP5 |
%E0 |
Disable
auto-retrain Enable auto-retrain Enable auto-retrain and fallback Enable auto-retrain and fast hang up |
%L |
Report received signal level in -dBm |
%N0 |
Dynamic CPU loading disabled Dynamic CPU loading not to exceed 10% Dynamic CPU loading not to exceed 20% Dynamic CPU loading not to exceed 30% Dynamic CPU loading not to exceed 40% Dynamic CPU loading not to exceed 50% Dynamic CPU loading not to exceed 60% Dynamic CPU loading not to exceed 70% Dynamic CPU loading not to exceed 80% Dynamic CPU loading not to exceed 90% |
%Q |
Report line signal quality |
| \A0 \A1 \A2 \A3 |
64-character
max. MNP block size 128-character max. MNP block size 192-character max. MNP block size 256-character max. MNP block size |
| \Bn | In non-error correction mode, transmit break in 100 ms units (1-9, default 3) |
| \G0 \G1 |
Disable
XON/XOFF flow control (modem to modem) Enable XON/XOFF flow control (modem to modem) |
| \Kn | Define break type (refer to table 2) |
| \L0 \L1 |
Use
stream mode for MNP Use interactive block mode for MNP |
| \N0 \N1 \N2 \N3 \N4 \N5 |
Normal mode; speed control without error
correction Plain mode; no speed control and no error correction Reliable mode Auto-reliable mode LAPM error correction only MNP error correction only |
*Q0 |
Send the "CONNECT xxxx" result
codes to the DTE when an invalid TIES escape sequence is detected after the
"OK" response has already been sent Does NOT send the "CONNECT xxxx" result codes to the DTE when an invalid TIES escape sequence is detected after the "OK" response has already been sent |