Appendix J. AT Command Set (Partial Listing)
AT Command Set (Partial listing)
All commands are preceded by AT. Commands can be grouped after one AT string.
| Command | Function | |
| A | Answer incoming call | |
| B0 | Use V.22 1200 baud connection | |
| B1 | Use Bell 212A 1200 baud connection | |
| Dxxx-xxxx | Dials a phone number: xxx-xxxx | D can be followed by: |
| ! Goes on hook for time given in S29 | ||
| , Pauses during dial (pause time is in S8) | ||
| S=#{#=0-3} Dials number stored in &Z# | ||
| ; (comes after dial string) Return to | ||
| command mode after dialing | ||
| @ Waits for 5 sec of silence before dialing | ||
| L | Redials last number dialed | |
| P | Pulse dial | |
| R | Accept command, but don't act on it [...] | |
| W | Wait for dial tone | |
| ^ | Turn on call tone | |
| E0 | Echo off - no command characters | |
| E1 | Echo command characters | |
| H0 | Hang up | |
| H1 | Off hook (same as hang up) | |
| I0 | Info - returns product code | |
| I1 | Info - Returns ROM checksum | |
| I2 | Info - Checks ROM checksum and returns OK or ERROR | |
| I3 | Info - Returns firmware revision code | |
| I4 | Info - Returns modem ID string | |
| I5 | Info - Returns country code | |
| I6 | Info - Returns data pump info | |
| L0 | Sets speaker volume to lowest | |
| L1 | Sets speaker volume to low | |
| L2 | Sets speaker volume to medium | |
| L3 | Sets speaker volume to highest | |
| M0 | Speaker off | |
| M1 | Speaker is on until a carrier detect | |
| M2 | Speaker is always on | |
| M3 | Speaker is on during answering only | |
| N0 | Disables automatic modulation negotation | |
| O0 | Puts modem in data mode | |
| O1 | Takes modem out of data mode | |
| P | Pulse dialing | |
| Q0 | Sets DTR line | |
| Q1 | Clears DTR line | |
| S# | Make S-register # default register | |
| S#=x | Set S-register # to x | |
| S#? | Returns value of register # | |
| T | Tone dialing | |
| V0 | Numeric responses | |
| V1 | Verbose responses | |
| W0 | Returns computer-modem speed | |
| W1 | Returns transfer rate and error correction protocol | |
| W2 | Returns modem-modem speed | |
| X0 | Verbose error codes | |
| X1 | X0 responses and connect speed | |
| X2 | X1 responses and NO DIALTONE | |
| X3 | X1 responses and BUSY | |
| X4 | All responses | |
| Y0 | Disable disconnection on pause | |
| Y1 | Enable disconnection on pause | |
| Z0 | Sets modem to profile 0 (set in &W0) | |
| Z1 | Sets modem to profile 1 (set in &W1) |
The following AT commands are not part of the original specification, and are called the "Extended AT" command set. Each command is preceded by a "&" symbol.
| &C0 | Sets DCD on |
| &C1 | Sets DCD to follow the actual carrier |
| &D0 | DTR active |
| &D1 | DTR drop as an escape sequence |
| &D2 | DTR drop as a hang up command |
| &D3 | DTR drop as a reset; loads profile from &Y |
| &F | Loads the factory profile (may be many) |
| &G0 | Disables gaurd tone |
| &G1 | Disables gaurd tone |
| &G2 | Enables 1800 Hz guard tone |
| &K0 | No flow control |
| &K3 | Hardware flow control |
| &K4 | Software (XON / XOFF) flow control |
| &M0 | No error correction; no speed control |
| &Q0 | Does same thing as &M0 |
| &Q5 | Modem negotiates error correction |
| &Q6 | &M0 with speed buffering |
| &S0 | Data Set Ready active |
| &S1 | DSR active after answer detected (until carrier is lost) |
| &T0-8 | {Engineering tests} |
| &V | Returns profiles [&Y] and stored numbers [&Z] |
| &W0 | Save current config as profile 0 |
| &W1 | Save current config as profile 1 |
| &Y0 | Modem uses profile 0 on startup |
| &Y1 | Modem uses profile 1 on startup |
| &Z#=x | Set stored number (0-3) to # |