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       # U.S. ROBOTICS, INC.
       
          COURIER HST
       
          Modem Type                   Data (synchronous/asynchronous)   
          Maximum Data Rate            9600bps                           
          Data Bus                     External                          
          Data Modulation Protocol     Bell 103A/212A                    
                                                                         
                                       ITU-T V.22bis                     
                                                                         
                                       USR HST                           
          Error Correction/Compression MNP5                              
       
   IMG IMG 1
          
       
          +------------------------------------------------------------+
          |                        CONNECTIONS                         |
          |------------------------------------------------------------|
          |     Purpose      | Location |      Purpose      | Location |
          |------------------+----------+-------------------+----------|
          | Line in          |   CN1    | DC power          |   CN4    |
          |------------------+----------+-------------------+----------|
          | Line out         |   CN2    | Power switch      |   SW2    |
          |------------------+----------+-------------------+----------|
          | RS-232/422       |   CN3    |                   |          |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                         DTR SIGNAL                         |
          |------------------------------------------------------------|
          | Setting                    |             SW1/1             |
          |----------------------------+-------------------------------|
          | » On                       |        DTR forced high        |
          |----------------------------+-------------------------------|
          | Off                        |          DTR normal           |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                        RESULT CODES                        |
          |------------------------------------------------------------|
          | Setting                    |             SW1/2             |
          |----------------------------+-------------------------------|
          | » Off                      |  Verbal result codes enabled  |
          |----------------------------+-------------------------------|
          | On                         | Numeric result codes enabled  |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                    RESULT CODES DISPLAY                    |
          |------------------------------------------------------------|
          | Setting                    |             SW1/3             |
          |----------------------------+-------------------------------|
          | » On                       |       Display disabled        |
          |----------------------------+-------------------------------|
          | Off                        |        Display enabled        |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                   ECHO COMMANDS DISPLAY                    |
          |------------------------------------------------------------|
          | Setting                    |             SW1/4             |
          |----------------------------+-------------------------------|
          | » Off                      |      Local echo enabled       |
          |----------------------------+-------------------------------|
          | On                         |      Local echo disabled      |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                        AUTO ANSWER                         |
          |------------------------------------------------------------|
          | Setting              |                SW1/5                |
          |----------------------+-------------------------------------|
          | » On                 | Modem does not answer on first ring |
          |----------------------+-------------------------------------|
          | Off                  |     Modem answers on first ring     |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                       CARRIER DETECT                       |
          |------------------------------------------------------------|
          | Setting                    |             SW1/6             |
          |----------------------------+-------------------------------|
          | » Off                      |           CD normal           |
          |----------------------------+-------------------------------|
          | On                         |        CD forced high         |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                MULTILINE PHONE INSTALLATION                |
          |------------------------------------------------------------|
          | Setting                    |             SW1/7             |
          |----------------------------+-------------------------------|
          | » Off                      |    Single phone connected     |
          |----------------------------+-------------------------------|
          | On                         |   Multiple phones connected   |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                       AT COMMAND SET                       |
          |------------------------------------------------------------|
          | Setting                    |             SW1/8             |
          |----------------------------+-------------------------------|
          | » On                       |   AT command set recognized   |
          |----------------------------+-------------------------------|
          | Off                        |    AT command set disabled    |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                        ESCAPE CODE                         |
          |------------------------------------------------------------|
          | Setting |                      SW1/9                       |
          |---------+--------------------------------------------------|
          | » On    |  Go to command mode and display OK result code   |
          |         |        when escape character is received         |
          |---------+--------------------------------------------------|
          | Off     |  Disconnect, go to command mode and display NO   |
          |         |    CARRIER when escape character is received     |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                        USER PROFILE                        |
          |------------------------------------------------------------|
          | Setting                    |            SW1/10             |
          |----------------------------+-------------------------------|
          | » Off                      |      Use stored profile       |
          |----------------------------+-------------------------------|
          | On                         |      Use factory default      |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                    TX/RX PIN ASSIGNMENT                    |
          |------------------------------------------------------------|
          | Setting                    |              SW3              |
          |----------------------------+-------------------------------|
          | » Off                      |       Normal operation        |
          |----------------------------+-------------------------------|
          | On                         | Reverse TX/RX pin assignments |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                     DIAGNOSTIC LED(S)                      |
          |------------------------------------------------------------|
          | LED | Color |  Status  |             Condition             |
          |-----+-------+----------+-----------------------------------|
          | HS  |  Red  |    On    |   Modem is operating at 9600bps   |
          |-----+-------+----------+-----------------------------------|
          | HS  |  Red  |   Off    | Modem is operating at slower than |
          |     |       |          |              9600bps              |
          |-----+-------+----------+-----------------------------------|
          | AA  |  Red  |    On    |        Auto-answer enabled        |
          |-----+-------+----------+-----------------------------------|
          | AA  |  Red  |   Off    |       Auto-answer disabled        |
          |-----+-------+----------+-----------------------------------|
          | CD  |  Red  |    On    |      Carrier signal detected      |
          |-----+-------+----------+-----------------------------------|
          | CD  |  Red  |   Off    |    Carrier signal not detected    |
          |-----+-------+----------+-----------------------------------|
          | OH  |  Red  |    On    |         Modem is off-hook         |
          |-----+-------+----------+-----------------------------------|
          | OH  |  Red  |   Off    |         Modem is on-hook          |
          |-----+-------+----------+-----------------------------------|
          | RD  |  Red  | Blinking |      Modem is receiving data      |
          |-----+-------+----------+-----------------------------------|
          | RD  |  Red  |   Off    |    Modem is not receiving data    |
          |-----+-------+----------+-----------------------------------|
          | TD  |  Red  | Blinking |    Modem is transmitting data     |
          |-----+-------+----------+-----------------------------------|
          | TD  |  Red  |   Off    |  Modem is not transmitting data   |
          |-----+-------+----------+-----------------------------------|
          | TR  |  Red  |    On    |        DTR signal is high         |
          |-----+-------+----------+-----------------------------------|
          | TR  |  Red  |   Off    |         DTR signal is low         |
          |-----+-------+----------+-----------------------------------|
          | MR  |  Red  |    On    |            Power is on            |
          |-----+-------+----------+-----------------------------------|
          | MR  |  Red  |   Off    |           Power is off            |
          |-----+-------+----------+-----------------------------------|
          | MR  |  Red  | Blinking |  Modem is retraining or in test   |
          |     |       |          |               mode.               |
          |-----+-------+----------+-----------------------------------|
          | RS  |  Red  |    On    |        RTS signal is high         |
          |-----+-------+----------+-----------------------------------|
          | RS  |  Red  |   Off    |         RTS signal is low         |
          |-----+-------+----------+-----------------------------------|
          | CS  |  Red  |    On    |        CTS signal is high         |
          |-----+-------+----------+-----------------------------------|
          | CS  |  Red  |   Off    |         CTS signal is low         |
          |-----+-------+----------+-----------------------------------|
          | EC  |  Red  |    On    |     Error correction enabled      |
          |-----+-------+----------+-----------------------------------|
          | EC  |  Red  |   Off    |     Error correction disabled     |
          |-----+-------+----------+-----------------------------------|
          | EC  |  Red  | Blinking |   Modem is retransmitting data    |
          |-----+-------+----------+-----------------------------------|
          | AL  |  Red  |    On    |  Analog loopback self test mode   |
          |     |       |          |             enabled.              |
          |-----+-------+----------+-----------------------------------|
          | AL  |  Red  |   Off    |         Normal operation          |
          +------------------------------------------------------------+
       
                            Proprietary AT Command Set
       
          +------------------------------------------------------------+
          |                  BIT-MAPPED REGISTER S13                   |
          |------------------------------------------------------------|
          | Format          | AT [cmds] S13=n [cmds]                   |
          |-----------------+------------------------------------------|
          | Example:        | ATS13=139<CR>                            |
          |-----------------+------------------------------------------|
          | Default:        | 0                                        |
          |-----------------+------------------------------------------|
          | Range:          | 0 - 255                                  |
          |-----------------+------------------------------------------|
          | Unit:           | Bit-mapped                               |
          |-----------------+------------------------------------------|
          | Description:    | Controls DTR reset, DTR dialing, reset   |
          |                 | dialing, and MNP3.                       |
          |------------------------------------------------------------|
          |   Bit    | Value  |                Function                |
          |----------+--------+----------------------------------------|
          |    0     | » 0 1  | DTR normal.                            |
          |          |        |                                        |
          |          |        | Reset on low DTR.                      |
          |----------+--------+----------------------------------------|
          |    1     | » 0 1  | Normal auto answer operation.          |
          |          |        |                                        |
          |          |        | When ring is received, enter originate |
          |          |        | and listen for answer tone.            |
          |----------+--------+----------------------------------------|
          |    2     | » 0 1  | Pause 250ms before displaying result   |
          |          |        | codes.                                 |
          |          |        |                                        |
          |          |        | Immediate result code display.         |
          |----------+--------+----------------------------------------|
          |    3     | » 0 1  | DTR dialing disabled.                  |
          |          |        |                                        |
          |          |        | DTR dialing enabled.                   |
          |----------+--------+----------------------------------------|
          |    4     | » 0 1  | Reset dialing disabled.                |
          |          |        |                                        |
          |          |        | Reset dialing enabled.                 |
          |----------+--------+----------------------------------------|
          |    5     | » 0    | Not used.                              |
          |----------+--------+----------------------------------------|
          |    6     | » 0 1  | MNP 3 enabled.                         |
          |          |        |                                        |
          |          |        | MNP 3 disabled.                        |
          |----------+--------+----------------------------------------|
          |    7     | » 0 1  | Hardware reset disabled.               |
          |          |        |                                        |
          |          |        | Hardware reset enabled.                |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                  BIT-MAPPED REGISTER S15                   |
          |------------------------------------------------------------|
          | Format:        | AT [cmds] S15=n [cmds]                    |
          |----------------+-------------------------------------------|
          | Example:       | ATS15=139<CR>                             |
          |----------------+-------------------------------------------|
          | Default:       | 0                                         |
          |----------------+-------------------------------------------|
          | Range:         | 0 - 255                                   |
          |----------------+-------------------------------------------|
          | Unit:          | Bit-mapped                                |
          |----------------+-------------------------------------------|
          | Description:   | Controls HST high frequency equalization, |
          |                | online fallback, back channel,            |
          |                | non-error-correcting mode buffer, MNP4,   |
          |                | BS/DEL switch, and MNP compliance.        |
          |------------------------------------------------------------|
          |   Bit    | Value |                Function                 |
          |----------+-------+-----------------------------------------|
          |    0     | » 0 1 | HST high frequency equalization         |
          |          |       | enabled.                                |
          |          |       |                                         |
          |          |       | HST high frequency equalization         |
          |          |       | disabled.                               |
          |----------+-------+-----------------------------------------|
          |    1     | » 0 1 | Online fallback enabled.                |
          |          |       |                                         |
          |          |       | Online fallback disabled.               |
          |----------+-------+-----------------------------------------|
          |    2     | » 0 1 | 450bps back channel enabled.            |
          |          |       |                                         |
          |          |       | 450bps back channel disabled.           |
          |----------+-------+-----------------------------------------|
          |    3     | » 0 1 | Non-error-correcting mode transmit      |
          |          |       | buffer set to 1.5KB.                    |
          |          |       |                                         |
          |          |       | Non-error-correcting mode transmit      |
          |          |       | buffer set to 128 bytes.                |
          |----------+-------+-----------------------------------------|
          |    4     | » 0 1 | MNP 4 enabled.                          |
          |          |       |                                         |
          |          |       | MNP 4 disabled.                         |
          |----------+-------+-----------------------------------------|
          |    5     | » 0 1 | Use backspace key for delete disabled.  |
          |          |       |                                         |
          |          |       | Use backspace key for delete enabled.   |
          |----------+-------+-----------------------------------------|
          |    6     | » 0 1 | MNP normal.                             |
          |          |       |                                         |
          |          |       | MNP adjusted for non compliant modems.  |
          |----------+-------+-----------------------------------------|
          |    7     | » 0 1 | Proprietary network compatibility       |
          |          |       | disabled.                               |
          |          |       |                                         |
          |          |       | Proprietary network compatibility       |
          |          |       | enabled.                                |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                        BREAK LENGTH                        |
          |------------------------------------------------------------|
          | Type:        | Register                                    |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] S21=n [cmds]                      |
          |--------------+---------------------------------------------|
          | Example:     | ATS21=20<CR>                                |
          |--------------+---------------------------------------------|
          | Default:     | 10                                          |
          |--------------+---------------------------------------------|
          | Range:       | Unidentified                                |
          |--------------+---------------------------------------------|
          | Unit:        | 10 ms                                       |
          |--------------+---------------------------------------------|
          | Description: | Sets the length of Error correction mode    |
          |              | breaks sent from DCE to DTE.                |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                         BREAK TYPE                         |
          |------------------------------------------------------------|
          | Type:        | Configuration                               |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] &Yn [cmds]                        |
          |--------------+---------------------------------------------|
          | Example:     | AT &Y0<CR>                                  |
          |--------------+---------------------------------------------|
          | Description: | Configures action of break signal.          |
          |--------------+---------------------------------------------|
          | Command      |                  Function                   |
          |--------------+---------------------------------------------|
          | &Y0          | Break empties buffer.                       |
          |--------------+---------------------------------------------|
          | » &Y1        | Break empties buffer and is sent            |
          |              | immediately.                                |
          |--------------+---------------------------------------------|
          | &Y2          | Break does not empty buffer and is sent     |
          |              | immediately.                                |
          |--------------+---------------------------------------------|
          | &Y3          | Break does not empty buffer and is sent     |
          |              | with transmitted data.                      |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                CONNECTION SPEED UPPER LIMIT                |
          |------------------------------------------------------------|
          | Type:        | Configuration                               |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] &Nn [cmds]                        |
          |--------------+---------------------------------------------|
          | Example:     | AT &N1 DT555-1212<CR>                       |
          |--------------+---------------------------------------------|
          | Description: | Sets required connection speed if &U is set |
          |              | to 0. Otherwise, sets fastest allowed       |
          |              | connection speed.                           |
          |--------------+---------------------------------------------|
          | Command      |                  Function                   |
          |--------------+---------------------------------------------|
          | » &N0        | Variable.                                   |
          |--------------+---------------------------------------------|
          | &N1          | 300bps                                      |
          |--------------+---------------------------------------------|
          | &N2          | 1200bps                                     |
          |--------------+---------------------------------------------|
          | &N3          | 2400bps                                     |
          |--------------+---------------------------------------------|
          | &N4          | 4800bps                                     |
          |--------------+---------------------------------------------|
          | &N5          | 7200bps                                     |
          |--------------+---------------------------------------------|
          | &N6          | 9600bps                                     |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                     DISCONNECT DISPLAY                     |
          |------------------------------------------------------------|
          | Type:        | Immediate                                   |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] S17? [cmds]                       |
          |--------------+---------------------------------------------|
          | Example:     | ATS17?<CR>                                  |
          |--------------+---------------------------------------------|
          | Default:     | Read only                                   |
          |--------------+---------------------------------------------|
          | Range:       | 1-6, 254, 255                               |
          |--------------+---------------------------------------------|
          | Description: | Displays the reason for a disconnect during |
          |              | error correcting mode.                      |
          |--------------+---------------------------------------------|
          |    Value     |                   Meaning                   |
          |--------------+---------------------------------------------|
          |    S17=1     | Received data different than requested.     |
          |--------------+---------------------------------------------|
          |    S17=2     | Incompatible MNP protocol.                  |
          |--------------+---------------------------------------------|
          |    S17=3     | Connection request parameters unknown.      |
          |--------------+---------------------------------------------|
          |    S17=4     | Remote modem retry timeout.                 |
          |--------------+---------------------------------------------|
          |    S17=5     | Inactivity timeout.                         |
          |--------------+---------------------------------------------|
          |    S17=6     | Destination user not found.                 |
          |--------------+---------------------------------------------|
          |   S17=254    | Peer protocol error.                        |
          |--------------+---------------------------------------------|
          |   S17=255    | User initiated disconnect.                  |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                   ERROR CORRECTION  MODE                   |
          |------------------------------------------------------------|
          | Type:        | Configuration                               |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] &Mn [cmds]                        |
          |--------------+---------------------------------------------|
          | Example:     | AT &M1 %C1<CR>                              |
          |--------------+---------------------------------------------|
          | Description: | Selects active error correction protocols.  |
          |--------------+---------------------------------------------|
          | Command      |                  Function                   |
          |--------------+---------------------------------------------|
          | &M0          | Normal mode only.                           |
          |--------------+---------------------------------------------|
          | » &M4        | Auto-detect mode.                           |
          |--------------+---------------------------------------------|
          | &M5          | ARQ mode only.                              |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                   EXTENDED RESULT CODES                    |
          |------------------------------------------------------------|
          | Type:        | Configuration                               |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] &An [cmds]                        |
          |--------------+---------------------------------------------|
          | Example:     | AT &A1 %C1<CR>                              |
          |--------------+---------------------------------------------|
          | Description: | Selects extended result codes.              |
          |--------------+---------------------------------------------|
          | Command      |                  Function                   |
          |--------------+---------------------------------------------|
          | &A0          | Extended result codes disabled.             |
          |--------------+---------------------------------------------|
          | » &A1        | ARQ result codes enabled.                   |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |               FLOW CONTROL CHARACTER - XOFF                |
          |------------------------------------------------------------|
          | Type:        | Register                                    |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] S23=n [cmds]                      |
          |--------------+---------------------------------------------|
          | Example:     | ATS23=20<CR>                                |
          |--------------+---------------------------------------------|
          | Default:     | 19                                          |
          |--------------+---------------------------------------------|
          | Range:       | 11-127                                      |
          |--------------+---------------------------------------------|
          | Unit:        | ASCII                                       |
          |--------------+---------------------------------------------|
          | Description: | Sets the character used to represent XOFF.  |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                FLOW CONTROL CHARACTER - XON                |
          |------------------------------------------------------------|
          | Type:        | Register                                    |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] S22=n [cmds]                      |
          |--------------+---------------------------------------------|
          | Example:     | ATS22=20<CR>                                |
          |--------------+---------------------------------------------|
          | Default:     | 17                                          |
          |--------------+---------------------------------------------|
          | Range:       | 11-127                                      |
          |--------------+---------------------------------------------|
          | Unit:        | ASCII                                       |
          |--------------+---------------------------------------------|
          | Description: | Sets the character used to represent XON.   |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                  FLOW CONTROL PASSTHROUGH                  |
          |------------------------------------------------------------|
          | Type:        | Configuration                               |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] &In [cmds]                        |
          |--------------+---------------------------------------------|
          | Example:     | AT &I0 &W<CR>                               |
          |--------------+---------------------------------------------|
          | Description: | Allows modem to act on, then transmit       |
          |              | XON/XOFF characters.                        |
          |--------------+---------------------------------------------|
          | Command      |                  Function                   |
          |--------------+---------------------------------------------|
          | » &I0        | Software flow control disabled.             |
          |--------------+---------------------------------------------|
          | &I1          | XON/XOFF passthrough enabled.               |
          |--------------+---------------------------------------------|
          | &I2          | XON/XOFF passthrough disabled.              |
          |--------------+---------------------------------------------|
          | &I3          | Hewlett-Packard host mode.                  |
          |--------------+---------------------------------------------|
          | &I4          | Hewlett-Packard Terminal mode.              |
          |--------------+---------------------------------------------|
          | &I5          | XON/XOFF passthrough for non error          |
          |              | correction mode enabled.                    |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                     FLOW CONTROL TYPE                      |
          |------------------------------------------------------------|
          | Type:        | Configuration                               |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] &Hn [cmds]                        |
          |--------------+---------------------------------------------|
          | Example:     | AT &H0 A<CR>                                |
          |--------------+---------------------------------------------|
          | Description: | Sets type of flow control used by modem.    |
          |--------------+---------------------------------------------|
          | Command      |                  Function                   |
          |--------------+---------------------------------------------|
          | » &H0        | Flow control disabled.                      |
          |--------------+---------------------------------------------|
          | &H1          | CTS/RTS flow control enabled.               |
          |--------------+---------------------------------------------|
          | &H2          | XON/XOFF flow control enabled.              |
          |--------------+---------------------------------------------|
          | &H3          | CTS/RTS and XON/XOFF flow control enabled.  |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                           PAUSE                            |
          |------------------------------------------------------------|
          | Type:        | Configuration                               |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] / [cmds]                          |
          |--------------+---------------------------------------------|
          | Example:     | AT /// &W<CR>                               |
          |--------------+---------------------------------------------|
          | Description: | 125ms pause for each /.                     |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                        HELP SCREENS                        |
          |------------------------------------------------------------|
          | Type:        | Immediate                                   |
          |--------------+---------------------------------------------|
          | Format:      | AT <prefix>$                                |
          |--------------+---------------------------------------------|
          | Example:     | AT &$<CR>                                   |
          |--------------+---------------------------------------------|
          | Description: | Shows command help screens for all commands |
          |              | beginning with the given prefix, or no      |
          |              | prefix if none is given.                    |
          |--------------+---------------------------------------------|
          |   Command    |                  Function                   |
          |--------------+---------------------------------------------|
          |      $       | Shows ATx help screen.                      |
          |--------------+---------------------------------------------|
          |      &$      | Shows AT& help screen.                      |
          |--------------+---------------------------------------------|
          |      D$      | Shows ATDx help screen.                     |
          |--------------+---------------------------------------------|
          |      S$      | Shows S-register help screen.               |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                      INACTIVITY TIMER                      |
          |------------------------------------------------------------|
          | Type:        | Register                                    |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] S19=n [cmds]                      |
          |--------------+---------------------------------------------|
          | Example:     | ATS19=20<CR>                                |
          |--------------+---------------------------------------------|
          | Default:     | 0                                           |
          |--------------+---------------------------------------------|
          | Range:       | Unidentified                                |
          |--------------+---------------------------------------------|
          | Unit:        | 1 minute                                    |
          |--------------+---------------------------------------------|
          | Description: | Sets the length of time that the modem does |
          |              | not receive information before it           |
          |              | disconnects.                                |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                     NO CARRIER DISPLAY                     |
          |------------------------------------------------------------|
          | Type:        | Immediate                                   |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] S20? [cmds]                       |
          |--------------+---------------------------------------------|
          | Example:     | ATS20?<CR>                                  |
          |--------------+---------------------------------------------|
          | Default:     | Read only                                   |
          |--------------+---------------------------------------------|
          | Range:       | 0-7                                         |
          |--------------+---------------------------------------------|
          | Description: | Displays the reason for a NO CARRIER result |
          |              | code..                                      |
          |--------------+---------------------------------------------|
          |    Value     |                   Meaning                   |
          |--------------+---------------------------------------------|
          |    S20=0     | Key press abort.                            |
          |--------------+---------------------------------------------|
          |    S20=1     | DTR low.                                    |
          |--------------+---------------------------------------------|
          |    S20=2     | Escape code sent.                           |
          |--------------+---------------------------------------------|
          |    S20=3     | Connection broken.                          |
          |--------------+---------------------------------------------|
          |    S20=4     | Inactivity timeout.                         |
          |--------------+---------------------------------------------|
          |    S20=5     | Automatic hangup with error correction      |
          |              | incompatibility .                           |
          |--------------+---------------------------------------------|
          |    S20=6     | Error correction retry timeout.             |
          |--------------+---------------------------------------------|
          |    S20=7     | Error correction received disconnect.       |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                        REGISTER S18                        |
          |------------------------------------------------------------|
          | Note: This register is reserved and should not be changed. |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                   REPEAT COMMAND STRING                    |
          |------------------------------------------------------------|
          | Type:        | Configuration                               |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] > [cmds]                          |
          |--------------+---------------------------------------------|
          | Example:     | AT *D1 > #E1<CR>                            |
          |--------------+---------------------------------------------|
          | Description: | Causes modem to repeat command string until |
          |              | a keyboard key is pressed.                  |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                     REPORT INFORMATION                     |
          |------------------------------------------------------------|
          | Type:        | Immediate                                   |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] In [cmds]                         |
          |--------------+---------------------------------------------|
          | Example:     | AT I1 O<CR>                                 |
          |--------------+---------------------------------------------|
          | Description: | Displays modem properties.                  |
          |--------------+---------------------------------------------|
          |   Command    |                  Function                   |
          |--------------+---------------------------------------------|
          |      I0      | Reports product code.                       |
          |--------------+---------------------------------------------|
          |      I1      | Reports ROM checksum result.                |
          |--------------+---------------------------------------------|
          |      I2      | Reports RAM checksum result.                |
          |--------------+---------------------------------------------|
          |      I3      | Reports call duration.                      |
          |--------------+---------------------------------------------|
          |      I4      | Reports current command settings.           |
          |--------------+---------------------------------------------|
          |      I5      | Reports current NVRAM settings.             |
          |--------------+---------------------------------------------|
          |      I6      | Reports current connection’s statistics.    |
          |--------------+---------------------------------------------|
          |      I7      | Reports configuration.                      |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                         TEST MODES                         |
          |------------------------------------------------------------|
          | Type:        | Register                                    |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] S16=n [cmds]                      |
          |--------------+---------------------------------------------|
          | Example:     | ATS16=0<CR>                                 |
          |--------------+---------------------------------------------|
          | Description: | Controls analog loopback pattern and dial   |
          |              | tests                                       |
          |--------------+---------------------------------------------|
          | Command      |                  Function                   |
          |--------------+---------------------------------------------|
          | » S16=0      | Testing disabled.                           |
          |--------------+---------------------------------------------|
          | S16=1        | Analog loopback test enabled.               |
          |--------------+---------------------------------------------|
          | S16=2        | Dial test enabled.                          |
          |--------------+---------------------------------------------|
          | S16=4        | Test pattern enabled.                       |
          |--------------+---------------------------------------------|
          | S16=5        | Analog loopback with test pattern enabled.  |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                        TIME DISPLAY                        |
          |------------------------------------------------------------|
          | Type:        | Immediate                                   |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] Kn [cmds]                         |
          |--------------+---------------------------------------------|
          | Example:     | AT K1 *L2 #E1<CR>                           |
          |--------------+---------------------------------------------|
          | Description: | Displays the current call time or clock     |
          |              | time.                                       |
          |--------------+---------------------------------------------|
          | Command      |                  Function                   |
          |--------------+---------------------------------------------|
          | » K0         | Display length of last call.                |
          |--------------+---------------------------------------------|
          | K1           | Display actual time.                        |
          +------------------------------------------------------------+