(TXT) View Source
       
       # MICROCOM, INC.
       
          QX/4232BIS+
       
          Card Type              Modem (synchronous/asynchronous)        
          Processor              Z80                                     
          Processor Speed        10MHz                                   
          Maximum Onboard Memory 64KB DRAM                               
          Maximum Data Rate      14.4Kbps                                
          Data Bus               Serial                                  
          Data Modulation        Bell 103A/212A                          
                                                                         
                                 ITU-T V.21, V.22, V.23, V.22bis, V.32,  
                                 V.32bis                                 
          Error                  MNP5, MNP10, V.42, V.42bis              
          Correction/Compression 
       
 (IMG) IMG 1
          
       
          +------------------------------------------------------------+
          |                        CONNECTIONS                         |
          |------------------------------------------------------------|
          |     Function     | Label |        Function         | Label |
          |------------------+-------+-------------------------+-------|
          | Line out         |  CN1  | Volume control          |  R1   |
          |------------------+-------+-------------------------+-------|
          | Line in          |  CN2  | Talk/Data switch        |  SW4  |
          |------------------+-------+-------------------------+-------|
          | AC power in      |  CN3  | Originate/Answer switch |  SW5  |
          |------------------+-------+-------------------------+-------|
          | RS232/422 port   |  CN4  | Reset switch            |  SW6  |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                 USER CONFIGURABLE SETTINGS                 |
          |------------------------------------------------------------|
          |                Setting                 | Label | Position  |
          |----------------------------------------+-------+-----------|
          | Minimum receive signal level set to    |  JP4  | Pins 1 &  |
          | -43 dBm                                |       | 2 closed  |
          |----------------------------------------+-------+-----------|
          | Minimum receive signal level set to    |  JP4  | Pins 2 &  |
          | -33 dBm                                |       | 3 closed  |
          |----------------------------------------+-------+-----------|
          | í Factory configured - do not alter    | JP8/A |  Closed   |
          |----------------------------------------+-------+-----------|
          | í Factory configured - do not alter    | JP8/B |   Open    |
          |----------------------------------------+-------+-----------|
          | í Factory configured - do not alter    | JP8/C |   Open    |
          |----------------------------------------+-------+-----------|
          | í Factory configured - do not alter    | JP9/A |  Closed   |
          |----------------------------------------+-------+-----------|
          | í Factory configured - do not alter    | JP9/B |   Open    |
          |----------------------------------------+-------+-----------|
          | í Factory configured - do not alter    | JP9/C |   Open    |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |             USER CONFIGURABLE SETTINGS (CON’T)             |
          |------------------------------------------------------------|
          |                Setting                | Label  | Position  |
          |---------------------------------------+--------+-----------|
          | Pin 1 of serial port connected to     |  JP10  | Pins 2 &  |
          | signal ground                         |        | 3 closed  |
          |---------------------------------------+--------+-----------|
          | Pin 1 of serial port connected to     |  JP10  | Pins 1 &  |
          | chassis ground                        |        | 2 closed  |
          |---------------------------------------+--------+-----------|
          | Pin 18 has no function                | JP11/A |   Open    |
          |---------------------------------------+--------+-----------|
          | Modem performs local analog loopback  | JP11/A |  Closed   |
          | test when pin 18 goes high            |        |           |
          |---------------------------------------+--------+-----------|
          | í Factory configured - do not alter   | SW3/7  |    On     |
          | (for North America)                   |        |           |
          |---------------------------------------+--------+-----------|
          | í Factory configured - do not alter   | SW3/8  |    On     |
          | (for North America)                   |        |           |
          |------------------------------------------------------------|
          |      Note: If pin 18 is enabled, busy out must be          |
          |      disabled.                                             |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                    LINE TYPE SELECTION                     |
          |------------------------------------------------------------|
          |        Setting         |   JP1/A   |   JP1/B   |   JP1/C   |
          |------------------------+-----------+-----------+-----------|
          |  Leased line (0 dBm)   |   Open    |   Open    |  Closed   |
          |------------------------+-----------+-----------+-----------|
          |  Permissive (-10 dBm)  |  Closed   |   Open    |   Open    |
          |------------------------+-----------+-----------+-----------|
          | Programmable (-12 dBm) |   Open    |  Closed   |   Open    |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                     BUSY OUT SELECTION                     |
          |------------------------------------------------------------|
          |         Setting          |     JP11/B     |     JP11/C     |
          |--------------------------+----------------+----------------|
          |     Busy out enabled     |     Closed     |      Open      |
          |--------------------------+----------------+----------------|
          |    Busy out disabled     |      Open      |     Closed     |
          |------------------------------------------------------------|
          |      Note: If busy out is enabled, pin 18 must be          |
          |      disabled.                                             |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |          LEASED LINE TRANSMISSION LEVEL SELECTION          |
          |------------------------------------------------------------|
          |    Setting    |    SW3/1     |    SW3/2     |    SW3/3     |
          |---------------+--------------+--------------+--------------|
          |    -2 dBm     |      On      |      On      |      On      |
          |---------------+--------------+--------------+--------------|
          |    -4 dBm     |     Off      |      On      |      On      |
          |---------------+--------------+--------------+--------------|
          |    -6 dBm     |      On      |     Off      |      On      |
          |---------------+--------------+--------------+--------------|
          |    -8 dBm     |     Off      |     Off      |      On      |
          |---------------+--------------+--------------+--------------|
          |    -10 dBm    |      On      |      On      |     Off      |
          |---------------+--------------+--------------+--------------|
          |    -12 dBm    |     Off      |      On      |     Off      |
          |---------------+--------------+--------------+--------------|
          |    -14 dBm    |      On      |     Off      |     Off      |
          |---------------+--------------+--------------+--------------|
          |    -16 dBm    |     Off      |     Off      |     Off      |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |         SWITCHED LINE TRANSMISSION LEVEL SELECTION         |
          |------------------------------------------------------------|
          |    Setting    |     SW3/4     |    SW3/5     |    SW3/6    |
          |---------------+---------------+--------------+-------------|
          |    -2 dBm     |      On       |      On      |     On      |
          |---------------+---------------+--------------+-------------|
          |    -4 dBm     |      Off      |      On      |     On      |
          |---------------+---------------+--------------+-------------|
          |    -6 dBm     |      On       |     Off      |     On      |
          |---------------+---------------+--------------+-------------|
          |    -8 dBm     |      Off      |     Off      |     On      |
          |---------------+---------------+--------------+-------------|
          |    -10 dBm    |      On       |      On      |     Off     |
          |---------------+---------------+--------------+-------------|
          |    -12 dBm    |      Off      |      On      |     Off     |
          |---------------+---------------+--------------+-------------|
          |    -14 dBm    |      On       |     Off      |     Off     |
          |---------------+---------------+--------------+-------------|
          |    -16 dBm    |      Off      |     Off      |     Off     |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                CONFIGURATION MODE FUNCTION                 |
          |------------------------------------------------------------|
          | Mode  |                      Function                      |
          |-------+----------------------------------------------------|
          |   0   | Normal operation of modem - sets power-up defaults |
          |       |                for various commands                |
          |-------+----------------------------------------------------|
          |   1   | Sets user profile that will be loaded at power-up  |
          |-------+----------------------------------------------------|
          |   2   |             Performs diagnostic tests              |
          |-------+----------------------------------------------------|
          |   3   |   Modifies factory default settings loaded by &F   |
          |       |                      command                       |
          |-------+----------------------------------------------------|
          |   4   | Sets power-up defaults for V.25bis synchronous and |
          |       |               dumb synchronous modes               |
          |------------------------------------------------------------|
          |      Note: The QX/4232bis+ modem can be configured by      |
          |      switches in five modes, although command              |
          |      configuration is preferable when possible.            |
          |      Configuration modes 1, 3, and 4 can be stored in      |
          |      NVRAM by pressing the reset switch. Mode 0 is read on |
          |      reset or power-up. Before operating, the modem’s      |
          |      switches should be returned to mode 0 and the         |
          |      appropriate settings made.                            |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                CONFIGURATION MODE SELECTION                |
          |------------------------------------------------------------|
          |Mode |Command Set|Async/Sync|  SW1/1   |SW1/2 |SW1/3 |SW1/9 |
          |-----+-----------+----------+----------+------+------+------|
          |  0  |    AT     |  Async   |See mode 0| Off  |  On  |  On  |
          |-----+-----------+----------+----------+------+------+------|
          |  0  |  V.25bis  |  Async   |See mode 0|  On  |  On  |  On  |
          |-----+-----------+----------+----------+------+------+------|
          |  1  |    N/A    |   N/A    |   Off    | Off  | Off  |  On  |
          |-----+-----------+----------+----------+------+------+------|
          |  2  |    N/A    |  Async   |See mode 2|  On  | Off  |  On  |
          |-----+-----------+----------+----------+------+------+------|
          |  2  |    N/A    |   Sync   |See mode 2|  On  | Off  | Off  |
          |-----+-----------+----------+----------+------+------+------|
          |  3  |    N/A    |   N/A    |    On    | Off  | Off  |  On  |
          |-----+-----------+----------+----------+------+------+------|
          |  4  |  V.25bis  |   Sync   |See mode 4|  On  |  On  | Off  |
          |-----+-----------+----------+----------+------+------+------|
          |  4  |   None    |   Sync   |See mode 4| Off  |  On  | Off  |
          +------------------------------------------------------------+
       
                     Configuration Mode 0 - Normal Operation
       
          +------------------------------------------------------------+
          |                 USER CONFIGURABLE SETTINGS                 |
          |------------------------------------------------------------|
          |                Setting                 | Label  | Position |
          |----------------------------------------+--------+----------|
          | í Modem goes to command mode and       | SW1/1  |    On    |
          | disconnects on low DTR                 |        |          |
          |----------------------------------------+--------+----------|
          | Modem ignores DTR                      | SW1/1  |   Off    |
          |----------------------------------------+--------+----------|
          | í Command echo enabled                 | SW1/4  |    On    |
          |----------------------------------------+--------+----------|
          | Command echo disabled                  | SW1/4  |   Off    |
          |----------------------------------------+--------+----------|
          | í Auto-answer on one ring              | SW1/5  |    On    |
          |----------------------------------------+--------+----------|
          | Auto-answer disabled                   | SW1/5  |   Off    |
          |----------------------------------------+--------+----------|
          | í Command sets enabled                 | SW1/8  |   Off    |
          |----------------------------------------+--------+----------|
          | Command sets disabled                  | SW1/8  |    On    |
          |----------------------------------------+--------+----------|
          | í Originate/Answer button determines   | SW1/10 |    On    |
          | mode                                   |        |          |
          |----------------------------------------+--------+----------|
          | Force answer mode                      | SW1/10 |   Off    |
          |----------------------------------------+--------+----------|
          | í Error correction result codes        | SW2/5  |   Off    |
          | enabled                                |        |          |
          |----------------------------------------+--------+----------|
          | Extended result codes disabled         | SW2/5  |    On    |
          |----------------------------------------+--------+----------|
          | í User profile loaded on reset and     | SW2/6  |    On    |
          | power up                               |        |          |
          |----------------------------------------+--------+----------|
          | Factory profile loaded on reset and    | SW2/6  |   Off    |
          | power up                               |        |          |
          |----------------------------------------+--------+----------|
          | í Switch configuration enabled         | SW2/7  |   Off    |
          |----------------------------------------+--------+----------|
          | Switch configuration disabled          | SW2/7  |    On    |
          |----------------------------------------+--------+----------|
          | í Serial port speed locked             | SW2/8  |   Off    |
          |----------------------------------------+--------+----------|
          | Serial port speed follows connect      | SW2/8  |    On    |
          | speed                                  |        |          |
          |------------------------------------------------------------|
          |      Note: SW2/8 has no function in V.25bis mode.          |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |           CD, CTS, AND DSR SIGNAL CONFIGURATION            |
          |------------------------------------------------------------|
          |                  Setting                   | SW1/6 | SW1/7 |
          |--------------------------------------------+-------+-------|
          |        CD, CTS, and DSR forced high        |  On   |  On   |
          |--------------------------------------------+-------+-------|
          | CD normal, CTS follows CD, DSR follows OH  |  On   |  Off  |
          |--------------------------------------------+-------+-------|
          |   CD, CTS, and DSR forced high except at   |  Off  |  On   |
          |                 disconnect                 |       |       |
          |--------------------------------------------+-------+-------|
          |    í CD normal, CTS and DSR forced high    |  Off  |  Off  |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                   FLOW CONTROL SELECTION                   |
          |------------------------------------------------------------|
          |                  Setting                   | SW2/1 | SW2/2 |
          |--------------------------------------------+-------+-------|
          |           Flow control disabled            |  On   |  On   |
          |--------------------------------------------+-------+-------|
          |    Bidirectional XON/XOFF flow control     |  On   |  Off  |
          |                  enabled                   |       |       |
          |--------------------------------------------+-------+-------|
          |    í Bidirectional RTS/CTS flow control    |  Off  |  On   |
          |                  enabled                   |       |       |
          |--------------------------------------------+-------+-------|
          |      CTS flow control by DCE enabled       |  Off  |  Off  |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                   CONNECT MODE SELECTION                   |
          |------------------------------------------------------------|
          |            Setting            |    SW2/3     |    SW2/4    |
          |-------------------------------+--------------+-------------|
          |      Normal mode enabled      |      On      |     On      |
          |-------------------------------+--------------+-------------|
          |   MNP reliable mode enabled   |      On      |     Off     |
          |-------------------------------+--------------+-------------|
          | í Auto-reliable mode enabled  |     Off      |     On      |
          |-------------------------------+--------------+-------------|
          |   LAPM or MNP reliable mode   |     Off      |     Off     |
          +------------------------------------------------------------+
       
                       Configuration Mode 1 - User Profile
       
          +------------------------------------------------------------+
          |                 USER CONFIGURABLE SETTINGS                 |
          |------------------------------------------------------------|
          |                Setting                 | Label  | Position |
          |----------------------------------------+--------+----------|
          | í Factory configured - do not alter    | SW1/6  |   N/A    |
          |----------------------------------------+--------+----------|
          | í Factory configured - do not alter    | SW1/7  |   N/A    |
          |----------------------------------------+--------+----------|
          | í Factory configured - do not alter    | SW1/8  |   N/A    |
          |----------------------------------------+--------+----------|
          | í Originate/Answer button determines   | SW1/10 |    On    |
          | mode                                   |        |          |
          |----------------------------------------+--------+----------|
          | Force answer mode                      | SW1/10 |   Off    |
          |----------------------------------------+--------+----------|
          | í Factory configured - do not alter    | SW2/1  |   N/A    |
          |----------------------------------------+--------+----------|
          | í Factory configured - do not alter    | SW2/2  |   N/A    |
          |----------------------------------------+--------+----------|
          | í Factory configured - do not alter    | SW2/3  |   N/A    |
          |----------------------------------------+--------+----------|
          | í Factory configured - do not alter    | SW2/4  |   N/A    |
          |----------------------------------------+--------+----------|
          | í Factory configured - do not alter    | SW2/5  |   N/A    |
          |----------------------------------------+--------+----------|
          | í Factory configured - do not alter    | SW2/6  |   N/A    |
          |----------------------------------------+--------+----------|
          | í Factory configured - do not alter    | SW2/7  |   N/A    |
          |----------------------------------------+--------+----------|
          | í Factory configured - do not alter    | SW2/8  |   N/A    |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                   USER PROFILE SELECTION                   |
          |------------------------------------------------------------|
          |           Setting           |    SW1/4     |     SW1/5     |
          |-----------------------------+--------------+---------------|
          |       User profile 0        |      On      |      On       |
          |-----------------------------+--------------+---------------|
          |       User profile 1        |      On      |      Off      |
          |-----------------------------+--------------+---------------|
          |       User profile 2        |     Off      |      On       |
          |-----------------------------+--------------+---------------|
          |       User profile 3        |     Off      |      Off      |
          +------------------------------------------------------------+
       
                    Configuration Mode 2 - Diagnostic Testing
       
          +------------------------------------------------------------+
          |                      TOGGLE SWITCHES                       |
          |------------------------------------------------------------|
          |      Function       |   Label    |   Function   |  Label   |
          |------------------------------------------------------------|
          | Start or stop test in       |   SW1/1   | Start or   | SW4 |
          | progress                    |           | stop test  |     |
          |                             |           | in         |     |
          |                             |           | progress   |     |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                 USER CONFIGURABLE SETTINGS                 |
          |------------------------------------------------------------|
          |                Setting                | Label  | Position  |
          |---------------------------------------+--------+-----------|
          | Modem will perform local digital      | SW1/4  |    Off    |
          | loopback test                         |        |           |
          |---------------------------------------+--------+-----------|
          | Modem will not perform local digital  | SW1/4  |    On     |
          | loopback test                         |        |           |
          |---------------------------------------+--------+-----------|
          | Modem will perform local analog       | SW1/5  |    Off    |
          | loopback test                         |        |           |
          |---------------------------------------+--------+-----------|
          | Modem will not perform local analog   | SW1/5  |    On     |
          | loopback test                         |        |           |
          |---------------------------------------+--------+-----------|
          | SW1/5 performs local analog loopback  | SW1/6  |    Off    |
          | with self-test                        |        |           |
          |---------------------------------------+--------+-----------|
          | SW1/5 performs local analog loopback  | SW1/6  |    On     |
          | test                                  |        |           |
          |---------------------------------------+--------+-----------|
          | í Factory configured - do not alter   | SW1/7  |    N/A    |
          |---------------------------------------+--------+-----------|
          | í Factory configured - do not alter   | SW1/8  |    N/A    |
          |---------------------------------------+--------+-----------|
          | í Factory configured - do not alter   | SW1/10 |    N/A    |
          |---------------------------------------+--------+-----------|
          | í Factory configured - do not alter   | SW2/1  |    N/A    |
          |---------------------------------------+--------+-----------|
          | í Factory configured - do not alter   | SW2/2  |    N/A    |
          |---------------------------------------+--------+-----------|
          | í Factory configured - do not alter   | SW2/3  |    N/A    |
          |---------------------------------------+--------+-----------|
          | í Factory configured - do not alter   | SW2/4  |    N/A    |
          |---------------------------------------+--------+-----------|
          | í Factory configured - do not alter   | SW2/5  |    N/A    |
          |---------------------------------------+--------+-----------|
          | í Factory configured - do not alter   | SW2/6  |    N/A    |
          |---------------------------------------+--------+-----------|
          | í Factory configured - do not alter   | SW2/7  |    N/A    |
          |---------------------------------------+--------+-----------|
          | í Factory configured - do not alter   | SW2/8  |    N/A    |
          |------------------------------------------------------------|
          |      Note: The modem will conduct tests in synchronous or  |
          |      asynchronous mode according to where SW1/9 was set    |
          |      the last time it was reset.                           |
          +------------------------------------------------------------+
       
               Configuration Mode 3 - Factory Default Modification
       
          +------------------------------------------------------------+
          |                 USER CONFIGURABLE SETTINGS                 |
          |------------------------------------------------------------|
          |                Setting                 | Label  | Position |
          |----------------------------------------+--------+----------|
          | Verbose result codes enabled           | SW1/6  |    On    |
          |----------------------------------------+--------+----------|
          | Numeric result codes enabled           | SW1/6  |   Off    |
          |----------------------------------------+--------+----------|
          | Pins 18 and 21 have no function        | SW1/7  |    On    |
          |----------------------------------------+--------+----------|
          | Perform local analog loopback test     | SW1/7  |   Off    |
          | when pin 18 is high, remote digital    |        |          |
          | loopback test when pin 21 is high      |        |          |
          |----------------------------------------+--------+----------|
          | \K set to 0                            | SW1/8  |   Off    |
          |----------------------------------------+--------+----------|
          | \K set to 5                            | SW1/8  |    On    |
          |----------------------------------------+--------+----------|
          | Originate/Answer button determines     | SW1/10 |    On    |
          | mode                                   |        |          |
          |----------------------------------------+--------+----------|
          | Force answer mode                      | SW1/10 |   Off    |
          |----------------------------------------+--------+----------|
          | Inactivity timer disabled              | SW2/1  |    On    |
          |----------------------------------------+--------+----------|
          | Inactivity timer set to 15 minutes     | SW2/1  |   Off    |
          |----------------------------------------+--------+----------|
          | Modem-to-modem flow control disabled   | SW2/2  |    On    |
          |----------------------------------------+--------+----------|
          | Modem-to-modem flow control enabled    | SW2/2  |   Off    |
          |----------------------------------------+--------+----------|
          | Parity checking of flow control and    | SW2/3  |    On    |
          | escape characters disabled             |        |          |
          |----------------------------------------+--------+----------|
          | Flow control and escape characters     | SW2/3  |   Off    |
          | will be processed only if their parity |        |          |
          | matches serial port                    |        |          |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                 RESULT CODE CONFIGURATION                  |
          |------------------------------------------------------------|
          |                Setting                 |  SW1/4  |  SW1/5  |
          |----------------------------------------+---------+---------|
          |          Result codes enabled          |   On    |   On    |
          |----------------------------------------+---------+---------|
          |         Result codes disabled          |   On    |   Off   |
          |----------------------------------------+---------+---------|
          | Result codes enabled on originate only |   Off   |   N/A   |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                      PARITY SELECTION                      |
          |------------------------------------------------------------|
          |              Setting               | SW2/4 | SW2/5 | SW2/6 |
          |------------------------------------+-------+-------+-------|
          | Modem will use eight data bits, no |  On   |  On   |  On   |
          |               parity               |       |       |       |
          |------------------------------------+-------+-------+-------|
          |  Modem will use seven data bits,   |  On   |  On   |  Off  |
          |             odd parity             |       |       |       |
          |------------------------------------+-------+-------+-------|
          |  Modem will use seven data bits,   |  On   |  Off  |  On   |
          |            even parity             |       |       |       |
          |------------------------------------+-------+-------+-------|
          |  Modem will use seven data bits,   |  On   |  Off  |  Off  |
          |            MARK parity             |       |       |       |
          |------------------------------------+-------+-------+-------|
          |  Modem will use seven data bits,   |  Off  |  On   |  On   |
          |            SPACE parity            |       |       |       |
          |------------------------------------+-------+-------+-------|
          |  Modem will use eight data bits,   |  Off  |  On   |  Off  |
          |             odd parity             |       |       |       |
          |------------------------------------+-------+-------+-------|
          |  Modem will use eight data bits,   |  Off  |  Off  |  On   |
          |            even parity             |       |       |       |
          |------------------------------------+-------+-------+-------|
          |  Modem will use eight data bits,   |  Off  |  Off  |  Off  |
          |            MARK parity             |       |       |       |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                      SPEED SELECTION                       |
          |------------------------------------------------------------|
          |                  Setting                   | SW2/7 | SW2/8 |
          |--------------------------------------------+-------+-------|
          |  Serial port speed set to 38.4Kbps; line   |  On   |  On   |
          |           speed set to 14.4Kbps            |       |       |
          |--------------------------------------------+-------+-------|
          |  Serial port speed set to 19.2Kbps; line   |  On   |  Off  |
          |           speed set to 14.4Kbps            |       |       |
          |--------------------------------------------+-------+-------|
          | Serial port and line speeds set to 9600bps |  Off  |  On   |
          |--------------------------------------------+-------+-------|
          |  Serial port speed set to 57.6Kbps; line   |  Off  |  Off  |
          |           speed set to 14.4Kbps            |       |       |
          +------------------------------------------------------------+
       
                     Configuration Mode 4 - Synchronous Mode
       
          +------------------------------------------------------------+
          |                 USER CONFIGURABLE SETTINGS                 |
          |------------------------------------------------------------|
          |                Setting                 | Label  | Position |
          |----------------------------------------+--------+----------|
          |   Modem goes to command mode and       | SW1/1  |    On    |
          |   disconnects on low-to-high DTR       |        |          |
          |   transition                           |        |          |
          |----------------------------------------+--------+----------|
          | Modem ignores DTR                      | SW1/1  |   Off    |
          |----------------------------------------+--------+----------|
          | Originate/Answer button determines     | SW1/10 |    On    |
          | mode                                   |        |          |
          |----------------------------------------+--------+----------|
          | Force answer mode                      | SW1/10 |   Off    |
          |----------------------------------------+--------+----------|
          | Pins 18 and 21 have no function        | SW2/3  |    On    |
          |----------------------------------------+--------+----------|
          |   Perform local analog loopback test   | SW2/3  |   Off    |
          |   when pin 18 is high, remote digital  |        |          |
          |   loopback test when pin 21 is high    |        |          |
          |----------------------------------------+--------+----------|
          | Auto-answer on one ring                | SW2/7  |   Off    |
          |----------------------------------------+--------+----------|
          | Auto-answer disabled                   | SW2/7  |    On    |
          |----------------------------------------+--------+----------|
          | Modem will match connect speeds.       | SW2/8  |    On    |
          |----------------------------------------+--------+----------|
          | Modem will connect only at current     | SW2/8  |   Off    |
          | speed.                                 |        |          |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                  STORED NUMBER SELECTION                   |
          |------------------------------------------------------------|
          |                  Setting                   | SW1/4 | SW1/5 |
          |--------------------------------------------+-------+-------|
          |              Manual dial only              |  On   |  On   |
          |--------------------------------------------+-------+-------|
          |  Dial first stored number when Talk/Data   |  On   |  Off  |
          |             switch is pressed              |       |       |
          |--------------------------------------------+-------+-------|
          |  Dial second stored number when Talk/Data  |  Off  |  On   |
          |             switch is pressed              |       |       |
          |--------------------------------------------+-------+-------|
          |  Dial third stored number when Talk/Data   |  Off  |  Off  |
          |             switch is pressed              |       |       |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                    LINE TYPE SELECTION                     |
          |------------------------------------------------------------|
          |              Setting               | SW1/6 | SW1/7 | SW1/8 |
          |------------------------------------+-------+-------+-------|
          |   Modem is connected to switched   |  On   |  On   |  On   |
          |                line                |       |       |       |
          |------------------------------------+-------+-------+-------|
          |    Modem is connected to 2-wire    |  Off  |  On   |  On   |
          |            leased line             |       |       |       |
          |------------------------------------+-------+-------+-------|
          |    Modem is connected to 4-wire    |  Off  |  Off  |  On   |
          |            leased line             |       |       |       |
          |------------------------------------+-------+-------+-------|
          |    Modem is connected to 2-wire    |  On   |  Off  |  On   |
          |  leased line. After 6 seconds of   |       |       |       |
          | receiving no input, the modem goes |       |       |       |
          | off-hook and attempts to connect.  |       |       |       |
          |------------------------------------+-------+-------+-------|
          |    Modem is connected to 4-wire    |  On   |  On   |  Off  |
          |  leased line. After 6 seconds of   |       |       |       |
          | receiving no input, the modem goes |       |       |       |
          | off-hook and attempts to connect.  |       |       |       |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                  CONNECT SPEED SELECTION                   |
          |------------------------------------------------------------|
          |            Setting             |    SW2/1    |    SW2/2    |
          |--------------------------------+-------------+-------------|
          | Modem will connect at 14.4Kbps |     On      |     On      |
          |--------------------------------+-------------+-------------|
          | Modem will connect at 9600bps  |     On      |     Off     |
          |--------------------------------+-------------+-------------|
          | Modem will connect at 4800bps  |     Off     |     On      |
          |--------------------------------+-------------+-------------|
          | Modem will connect at 2400bps  |     Off     |     Off     |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |         CD, CTS, DSR, AND RTS SIGNAL CONFIGURATION         |
          |------------------------------------------------------------|
          |              Setting               | SW2/4 | SW2/5 | SW2/6 |
          |------------------------------------+-------+-------+-------|
          |    CD, CTS, and DSR forced high    |  On   |  On   |  On   |
          |------------------------------------+-------+-------+-------|
          |      CD, CTS, and DSR normal       |  On   |  On   |  Off  |
          |------------------------------------+-------+-------+-------|
          |    CD, CTS, and DSR forced high    |  On   |  Off  |  On   |
          |        except at disconnect        |       |       |       |
          |------------------------------------+-------+-------+-------|
          | CD normal, CTS and DSR forced high |  On   |  Off  |  Off  |
          |------------------------------------+-------+-------+-------|
          |      CD, CTS, and DSR normal       |  Off  |  On   |  On   |
          |------------------------------------+-------+-------+-------|
          |  CD normal, CTS follows RTS, DSR   |  Off  |  On   |  Off  |
          |            forced high             |       |       |       |
          |------------------------------------+-------+-------+-------|
          |    CD and CTS use ITU-T V.13 to    |  Off  |  Off  |  On   |
          |  simulate half-duplex modes, DSR   |       |       |       |
          |               normal               |       |       |       |
          |------------------------------------+-------+-------+-------|
          |    CD and CTS use ITU-T V.13 to    |  Off  |  Off  |  Off  |
          |  simulate half-duplex modes, DSR   |       |       |       |
          |            forced high             |       |       |       |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                DIAGNOSTIC LED(S) (POWER-UP)                |
          |------------------------------------------------------------|
          |  TST   |   OH   |    HS    |           Condition           |
          |--------+--------+----------+-------------------------------|
          |   On   |  Off   |   Off    |  Firmware checksum incorrect  |
          |--------+--------+----------+-------------------------------|
          |   On   |  Off   |   Red    |        RAM test failed        |
          |--------+--------+----------+-------------------------------|
          |   On   |  Off   |  Green   |         Modem failed          |
          |--------+--------+----------+-------------------------------|
          |   On   |   On   |   N/A    |         Modem failed          |
          |--------+--------+----------+-------------------------------|
          |  Off   |  Off   |   Off    |       All tests passed        |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |            DIAGNOSTIC LED(S) (NORMAL OPERATION)            |
          |------------------------------------------------------------|
          | LED |    Color     |  Status  |         Condition          |
          |-----+--------------+----------+----------------------------|
          | PWR | Unidentified |    On    |        Power is on         |
          |-----+--------------+----------+----------------------------|
          | PWR | Unidentified |   Off    |        Power is off        |
          |-----+--------------+----------+----------------------------|
          | TST | Unidentified |    On    | System error has occurred  |
          |     |              |          |   or modem is retraining   |
          |-----+--------------+----------+----------------------------|
          | TST | Unidentified | Blinking | Serial port is waiting to  |
          |     |              |          |       be configured        |
          |-----+--------------+----------+----------------------------|
          | TST | Unidentified |   One    |  Data error has occurred   |
          |     |              |  blink   |                            |
          |-----+--------------+----------+----------------------------|
          | TST | Unidentified |   Off    |      Normal operation      |
          |-----+--------------+----------+----------------------------|
          | OH  | Unidentified |    On    |     Modem is off-hook      |
          |-----+--------------+----------+----------------------------|
          | OH  | Unidentified |   Off    |      Modem is on-hook      |
          |-----+--------------+----------+----------------------------|
          | HS  |     Red      |    On    | Modem is connected at, or  |
          |     |              |          |  serial port speed is set  |
          |     |              |          |         to, 300bps         |
          |-----+--------------+----------+----------------------------|
          | HS  |     Red      | 1 blink  | Modem is connected at, or  |
          |     |              |          |  serial port speed is set  |
          |     |              |          |         to, 600bps         |
          |-----+--------------+----------+----------------------------|
          | HS  |     Red      | 2 blinks | Modem is connected at, or  |
          |     |              |          |  serial port speed is set  |
          |     |              |          |        to, 1200bps         |
          |-----+--------------+----------+----------------------------|
          | HS  |     Red      | 3 blinks | Modem is connected at, or  |
          |     |              |          |  serial port speed is set  |
          |     |              |          |        to, 2400bps         |
          |-----+--------------+----------+----------------------------|
          | HS  |    Green     |    On    | Modem is connected at, or  |
          |     |              |          |  serial port speed is set  |
          |     |              |          |        to, 4800bps         |
          |-----+--------------+----------+----------------------------|
          | HS  |    Green     | 1 blink  | Modem is connected at, or  |
          |     |              |          |  serial port speed is set  |
          |     |              |          |        to, 7200bps         |
          |-----+--------------+----------+----------------------------|
          | HS  |    Green     | 2 blinks | Modem is connected at, or  |
          |     |              |          |  serial port speed is set  |
          |     |              |          |        to, 9600bps         |
          |-----+--------------+----------+----------------------------|
          | HS  |    Green     | 3 blinks | Modem is connected at, or  |
          |     |              |          |  serial port speed is set  |
          |     |              |          |         to, 12Kbps         |
          |-----+--------------+----------+----------------------------|
          | HS  |    Green     | 4 blinks | Modem is connected at, or  |
          |     |              |          |  serial port speed is set  |
          |     |              |          |        to, 14.4Kbps        |
          |-----+--------------+----------+----------------------------|
          | HS  |     N/A      |   Off    | Modem is connected at, or  |
          |     |              |          |  serial port speed is set  |
          |     |              |          |         to, 75bps          |
          |-----+--------------+----------+----------------------------|
          | DTR | Unidentified |    On    |     DTR signal is high     |
          |-----+--------------+----------+----------------------------|
          | DTR | Unidentified |   Off    |     DTR signal is low      |
          |-----+--------------+----------+----------------------------|
          | TXD | Unidentified | Blinking | Modem is transmitting data |
          |-----+--------------+----------+----------------------------|
          | TXD | Unidentified |   Off    | Modem is not transmitting  |
          |     |              |          |            data            |
          |-----+--------------+----------+----------------------------|
          | RXD | Unidentified | Blinking |  Modem is receiving data   |
          |-----+--------------+----------+----------------------------|
          | RXD | Unidentified |   Off    |   Modem is not receiving   |
          |     |              |          |            data            |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                SUPPORTED STANDARD COMMANDS                 |
          |------------------------------------------------------------|
          |                     Basic AT Commands                      |
          |------------------------------------------------------------|
          | +++, ‘comma’, A/                                           |
          |------------------------------------------------------------|
          | A, B, E, H, I, L, M, O, P, Q, T, V, W, X, Y, Z             |
          |------------------------------------------------------------|
          | &D, &F, &G, &M, &P, &T, &W, &X, &Y, &Z                     |
          |------------------------------------------------------------|
          |                    Extended AT Commands                    |
          |------------------------------------------------------------|
          | \A, \B, \C, \E, \J, \N, \Q, \T                             |
          |------------------------------------------------------------|
          | %A, %C, %E, %F, %G                                         |
          |------------------------------------------------------------|
          |                    Special AT Commands                     |
          |------------------------------------------------------------|
          | -J, *H, )M, @M, :E                                         |
          |------------------------------------------------------------|
          |                        S-Registers                         |
          |------------------------------------------------------------|
          | S0, S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S12, S14,     |
          | S16, S18, S22, S23, S25, S26, S27                          |
          |------------------------------------------------------------|
          |      Note: See MHI documentation for complete information. |
          +------------------------------------------------------------+
       
                            Proprietary AT Command Set
       
          +------------------------------------------------------------+
          |                   COMMAND SET - V.25bis                    |
          |------------------------------------------------------------|
          | Type:        | Immediate                                   |
          |--------------+---------------------------------------------|
          | Format:      | [cmds] \M                                   |
          |--------------+---------------------------------------------|
          | Description: | Enables the V.25bis command set.            |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                  DISPLAY SWITCH SETTINGS                   |
          |------------------------------------------------------------|
          | Type:        | Immediate                                   |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] %Sn [cmds]                        |
          |--------------+---------------------------------------------|
          | Description: | Displays the modem’s switch settings.       |
          |------------------------------------------------------------|
          |     Command     |                 Function                 |
          |-----------------+------------------------------------------|
          |       %S0       | Display settings of SW1/1-SW1/10.        |
          |-----------------+------------------------------------------|
          |       %S1       | Display settings of SW2/1-SW2/8.         |
          |-----------------+------------------------------------------|
          |       %S2       | Display settings of SW3/1-SW3/8.         |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                 LEASED LINE CALL RESTORAL                  |
          |------------------------------------------------------------|
          | Type:        | Configuration                               |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] )Pn [cmds]                        |
          |--------------+---------------------------------------------|
          | Description: | Selects whether the modem will attempt to   |
          |              | reconnect with a dial backup call to a      |
          |              | leased line MNP reliable mode connection    |
          |              | that has terminated abnormally. If the dial |
          |              | backup reconnects successfully, the call    |
          |              | will proceed as if it had not disconnected. |
          |------------------------------------------------------------|
          |     Command      |                Function                 |
          |------------------+-----------------------------------------|
          |       )P0        | Leased line call restoral disabled.     |
          |------------------+-----------------------------------------|
          |      í )P1       | Leased line call restoral enabled.      |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |              LEASED LINE COMPROMISE EQUALIZER              |
          |------------------------------------------------------------|
          | Type:        | Configuration                               |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] )En [cmds]                        |
          |--------------+---------------------------------------------|
          | Description: | Selects whether the compromise equalizer    |
          |              | will be used for leased line V.32 and       |
          |              | V.32bis connections.                        |
          |------------------------------------------------------------|
          |      Command      |                Function                |
          |-------------------+----------------------------------------|
          |       í )E0       | Compromise equalizer disabled.         |
          |-------------------+----------------------------------------|
          |        )E1        | Compromise equalizer enabled.          |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                  LEASED LINE DIAL BACKUP                   |
          |------------------------------------------------------------|
          | Type:        | Configuration                               |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] :Nn [cmds]                        |
          |--------------+---------------------------------------------|
          | Description: | Selects whether the modem will attempt to   |
          |              | connect to the first stored number with a   |
          |              | switched line connection if the leased line |
          |              | connection fails.                           |
          |------------------------------------------------------------|
          |         Command         |             Function             |
          |-------------------------+----------------------------------|
          |           :N0           | Dial backup disabled.            |
          |-------------------------+----------------------------------|
          |          í :N1          | Dial backup enabled.             |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |           LEASED LINE DIAL BACKUP IN ANSWER MODE           |
          |------------------------------------------------------------|
          | Type:        | Configuration                               |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] )Cn [cmds]                        |
          |--------------+---------------------------------------------|
          | Description: | Selects whether the modem is allowed to     |
          |              | execute a dial backup if it is in answer    |
          |              | mode.                                       |
          |------------------------------------------------------------|
          |    Command     |                 Function                  |
          |----------------+-------------------------------------------|
          |      )C0       | Dial backup disabled in answer mode.      |
          |----------------+-------------------------------------------|
          |     í )C1      | Dial backup enabled in answer mode.       |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |            LEASED LINE MAXIMUM RETRAIN COUNTER             |
          |------------------------------------------------------------|
          | Type:        | Configuration                               |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] :Gn [cmds]                        |
          |--------------+---------------------------------------------|
          | Description: | Sets the number of times the modem is       |
          |              | allowed to retrain in the time specified by |
          |              | the :H command before it attempts a dial    |
          |              | backup connection.                          |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |              LEASED LINE MAXIMUM RETRAIN TIME              |
          |------------------------------------------------------------|
          | Type:        | Configuration                               |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] :Hn [cmds]                        |
          |--------------+---------------------------------------------|
          | Default:     | 0                                           |
          |--------------+---------------------------------------------|
          | Range:       | 0 - 255                                     |
          |--------------+---------------------------------------------|
          | Unit:        | 1 minute                                    |
          |--------------+---------------------------------------------|
          | Description: | Sets the amount of time in which the modem  |
          |              | is allowed to retrain the number of times   |
          |              | specified by the :G command before it       |
          |              | attempts a dial backup connection.          |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |              LEASED LINE ORIGINATE MODE TIMER              |
          |------------------------------------------------------------|
          | Type:        | Configuration                               |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] &Vn [cmds]                        |
          |--------------+---------------------------------------------|
          | Default:     | 5                                           |
          |--------------+---------------------------------------------|
          | Range:       | 0 - 90                                      |
          |--------------+---------------------------------------------|
          | Unit:        | 1 minute                                    |
          |--------------+---------------------------------------------|
          | Description: | Sets the amount of time that the            |
          |              | originating modem waits for an answer       |
          |              | before attempting a dial backup.            |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                    LEASED LINE QUALITY                     |
          |------------------------------------------------------------|
          | Type:        | Immediate                                   |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] )F [cmds]                         |
          |--------------+---------------------------------------------|
          | Default:     | N/A                                         |
          |--------------+---------------------------------------------|
          | Range:       | 0 - 65535                                   |
          |--------------+---------------------------------------------|
          | Unit:        | N/A                                         |
          |--------------+---------------------------------------------|
          | Description: | Displays the poorest quality of the phone   |
          |              | line this connection. Higher numbers        |
          |              | indicate a poorer connection.               |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                 LEASED LINE QUALITY CLEAR                  |
          |------------------------------------------------------------|
          | Type:        | Configuration                               |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] :Y [cmds]                         |
          |--------------+---------------------------------------------|
          | Description: | Clears the line quality value reported by   |
          |              | )F so that the current line quality may be  |
          |              | monitored.                                  |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                    LEASED LINE RESTORAL                    |
          |------------------------------------------------------------|
          | Type:        | Configuration                               |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] )Ln [cmds]                        |
          |--------------+---------------------------------------------|
          | Description: | Selects whether the modem will attempt to   |
          |              | restore a leased line connection while      |
          |              | connected with a dial backup connection.    |
          |------------------------------------------------------------|
          |    Command    |                  Function                  |
          |---------------+--------------------------------------------|
          |      )L0      | Modem will not attempt to restore leased   |
          |               | line connection.                           |
          |---------------+--------------------------------------------|
          |     í )L1     | Modem will attempt to restore leased line  |
          |               | connection.                                |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |             LEASED LINE RESTORAL CARRIER TIMER             |
          |------------------------------------------------------------|
          | Type:        | Configuration                               |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] )Wn [cmds]                        |
          |--------------+---------------------------------------------|
          | Default:     | 20                                          |
          |--------------+---------------------------------------------|
          | Range:       | 0 - 255                                     |
          |--------------+---------------------------------------------|
          | Unit:        | 1 second                                    |
          |--------------+---------------------------------------------|
          | Description: | Sets the amount of time that the modem      |
          |              | waits for a carrier after attempting to     |
          |              | restore a leased line connection. If this   |
          |              | time expires the modem will begin a dial    |
          |              | backup again.                               |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                 LEASED LINE RESTORAL DELAY                 |
          |------------------------------------------------------------|
          | Type:        | Configuration                               |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] )Xn [cmds]                        |
          |--------------+---------------------------------------------|
          | Default:     | 60                                          |
          |--------------+---------------------------------------------|
          | Range:       | 0 - 60                                      |
          |--------------+---------------------------------------------|
          | Unit:        | 1 minute                                    |
          |--------------+---------------------------------------------|
          | Description: | Sets the amount of time that the modem      |
          |              | waits after a successful dial backup to     |
          |              | check the leased line to see if service has |
          |              | been re-established.                        |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |              LEASED LINE RESTORAL RETRY DELAY              |
          |------------------------------------------------------------|
          | Type:        | Configuration                               |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] )Yn [cmds]                        |
          |--------------+---------------------------------------------|
          | Default:     | 40                                          |
          |--------------+---------------------------------------------|
          | Range:       | 0 - 255                                     |
          |--------------+---------------------------------------------|
          | Unit:        | 1 second                                    |
          |--------------+---------------------------------------------|
          | Description: | Sets the amount of time after a failed      |
          |              | attempt to re-connect to the leased line,   |
          |              | and while it is performing a dial backup,   |
          |              | that the modem watches for a carrier on the |
          |              | leased line. If no carrier is detected      |
          |              | within this time the modem proceeds with    |
          |              | the dial backup.                            |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                    LEASED LINE RESTORE                     |
          |------------------------------------------------------------|
          | Type:        | Immediate                                   |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] )B [cmds]                         |
          |--------------+---------------------------------------------|
          | Description: | Initiates a leased line restoral.           |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                         LINE TYPE                          |
          |------------------------------------------------------------|
          | Type:        | Configuration                               |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] &Ln [cmds]                        |
          |--------------+---------------------------------------------|
          | Description: | Selects what type of line the modem is      |
          |              | connected to and whether it will attempt to |
          |              | automatically re-connect.                   |
          |------------------------------------------------------------|
          |    Command     |                 Function                  |
          |----------------+-------------------------------------------|
          |     í &L0      | Modem is connected to switched line.      |
          |----------------+-------------------------------------------|
          |      &L1       | Modem is connected to 2-wire leased line. |
          |----------------+-------------------------------------------|
          |      &L2       | Modem is connected to 4-wire leased line. |
          |----------------+-------------------------------------------|
          |      &L3       | Modem is connected to 2-wire leased line. |
          |                | After 6 seconds of receiving no input,    |
          |                | the modem goes off-hook and attempts to   |
          |                | connect.                                  |
          |----------------+-------------------------------------------|
          |      &L4       | Modem is connected to 4-wire leased line. |
          |                | After 6 seconds of receiving no input,    |
          |                | the modem goes off-hook and attempts to   |
          |                | connect.                                  |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                       OPERATING MODE                       |
          |------------------------------------------------------------|
          | Type:        | Configuration                               |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] $Sn [cmds]                        |
          |--------------+---------------------------------------------|
          | Description: | Selects whether the modem will operate in   |
          |              | asynchronous or synchronous mode.           |
          |------------------------------------------------------------|
          |        Command        |              Function              |
          |-----------------------+------------------------------------|
          |         í $S0         | Determined by SW1/9.               |
          |-----------------------+------------------------------------|
          |          $S1          | Force asynchronous mode.           |
          |-----------------------+------------------------------------|
          |          $S2          | Force synchronous mode.            |
          +------------------------------------------------------------+
       
                         Proprietary V.25bis Command Set
       
          +------------------------------------------------------------+
          |                      COMMAND SET - AT                      |
          |------------------------------------------------------------|
          | Type:        | Immediate                                   |
          |--------------+---------------------------------------------|
          | Format:      | ATZ                                         |
          |--------------+---------------------------------------------|
          | Description: | Enables the AT command set.                 |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |   CONNECTION SECURITY - PASSWORD SELECTION (ASYNCHRONOUS   |
          |                           MODE)                            |
          |------------------------------------------------------------|
          | Type:        | Configuration                               |
          |--------------+---------------------------------------------|
          | Format:      | PSW                                         |
          |--------------+---------------------------------------------|
          | Description: | Changes the connection password. The user   |
          |              | will be prompted to enter the old and new   |
          |              | passwords. Passwords must be exactly five   |
          |              | characters, case insensitive.               |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |   CONNECTION SECURITY - PASSWORD SELECTION (SYNCHRONOUS    |
          |                           MODE)                            |
          |------------------------------------------------------------|
          | Type:        | Configuration                               |
          |--------------+---------------------------------------------|
          | Format:      | PSWxxxxx;yyyyy                              |
          |--------------+---------------------------------------------|
          | Description: | Changes the connection password. The xxxxx  |
          |              | represents old connection password, and the |
          |              | yyyyy is the new connection password.       |
          |              | Passwords must be exactly five characters,  |
          |              | case insensitive.                           |
          +------------------------------------------------------------+
       
          See MICROCOM, INC. DESKPORTE FAST for a full command summary.