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       # HAYES MICROCOMPUTER PRODUCTS, INC.
       
          ULTRA SMARTMODEM 9600
       
          Card Type              Fax, Modem (synchronous/asynchronous)   
          Chip Set               Unidentified                            
          Maximum Data Rate      9600bps                                 
          Data Bus               External                                
          Data Modulation        Bell 103/212A                           
          Protocol                                                       
                                 ITU-T V.21, V.22, V.22bis, V.23, V.32   
          Error                  Adaptive data compression, V-series     
          Correction/Compression LAPB, MNP5, V.42, V.42bis, X.25         
       
   IMG IMG 1
          
       
          +------------------------------------------------------------+
          |                        CONNECTIONS                         |
          |------------------------------------------------------------|
          |       Function        | Label  |   Function    |   Label   |
          |------------------------------------------------------------|
          | Line in                   |   CN1    | DC power     | CN4  |
          |---------------------------+----------+--------------+------|
          | Line out                  |   CN2    | Power switch | SW2  |
          |---------------------------+----------+--------------+------|
          | RS-232/422                |   CN3    |              |      |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                   COMMAND SET SELECTION                    |
          |------------------------------------------------------------|
          |           Setting           |     SW1/C     |    SW1/D     |
          |-----------------------------+---------------+--------------|
          |      AT commands only       |      Up       |      Up      |
          |-----------------------------+---------------+--------------|
          |    Asynchronous V.25bis     |      Up       |     Down     |
          |-----------------------------+---------------+--------------|
          |     Synchronous V.25bis     |     Down      |      Up      |
          |                             |               |              |
          |        HDLC framing         |               |              |
          |-----------------------------+---------------+--------------|
          |     Synchronous V.25bis     |     Down      |     Down     |
          |                             |               |              |
          |      Character framing      |               |              |
          |------------------------------------------------------------|
          | Note: Our normal convention for switches is On/Off, this   |
          | document will use Up/Down.                                 |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                 USER CONFIGURABLE SETTINGS                 |
          |------------------------------------------------------------|
          |                 Setting                 | Label | Position |
          |-----------------------------------------+-------+----------|
          | Command recognition enabled/smart mode  | SW1/A |    Up    |
          |-----------------------------------------+-------+----------|
          | Command recognition disabled/dumb mode  | SW1/A |   Down   |
          |-----------------------------------------+-------+----------|
          | Carrier signal adjustment disabled      | SW1/B |    Up    |
          |-----------------------------------------+-------+----------|
          | Carrier signal adjustment enabled       | SW1/B |   Down   |
          |------------------------------------------------------------|
          | Note: Our normal convention for switches is On/Off, this   |
          | document will use Up/Down.                                 |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                     DIAGNOSTIC LED(S)                      |
          |------------------------------------------------------------|
          | LED | Color |  Status  |             Condition             |
          |-----+-------+----------+-----------------------------------|
          | HS  |  Red  |    On    | Modem is operating at 4800bps or  |
          |     |       |          |              faster               |
          |-----+-------+----------+-----------------------------------|
          | HS  |  Red  |   Off    | Modem is operating at slower than |
          |     |       |          |              4800bps              |
          |-----+-------+----------+-----------------------------------|
          | AA  |  Red  |    On    |     Auto-answer enabled/ring      |
          |     |       |          |    indicated when Auto-answer     |
          |     |       |          |             disabled              |
          |-----+-------+----------+-----------------------------------|
          | AA  |  Red  |   Off    |     Auto-answer disabled/ring     |
          |     |       |          |    indicated when Auto-answer     |
          |     |       |          |              enabled              |
          |-----+-------+----------+-----------------------------------|
          | 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  |    On    |      Modem is receiving data      |
          |-----+-------+----------+-----------------------------------|
          | RD  |  Red  |   Off    |    Modem is not receiving data    |
          |-----+-------+----------+-----------------------------------|
          | SD  |  Red  |    On    |    Modem is transmitting data     |
          |-----+-------+----------+-----------------------------------|
          | SD  |  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 |   Self-test or diagnostic mode    |
          |     |       |          |              enabled              |
          +------------------------------------------------------------+
       
                            Proprietary AT Command Set
       
          +------------------------------------------------------------+
          |                            DIAL                            |
          |------------------------------------------------------------|
          | Type:        | Immediate                                   |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] D<#> [cmds]                       |
          |--------------+---------------------------------------------|
          | Description: | Dials telephone number according to any     |
          |              | modifiers included in the string            |
          |--------------+---------------------------------------------|
          | Note:        | Any combination of modifiers can be used to |
          |              | produce the desired dial functions in       |
          |              | sequence.                                   |
          |--------------+---------------------------------------------|
          |   Modifier   |                  Function                   |
          |--------------+---------------------------------------------|
          |      P       | Pulse dialing enabled                       |
          |--------------+---------------------------------------------|
          |      R       | Answer mode enabled, originate mode         |
          |              | disabled following handshake initiation.    |
          |--------------+---------------------------------------------|
          |     S=n      | Dial stored telephone number n              |
          |--------------+---------------------------------------------|
          |      T       | Tone dialing enabled                        |
          |--------------+---------------------------------------------|
          |      W       | Dialing resumed following dial tone         |
          |              | detection                                   |
          |--------------+---------------------------------------------|
          |      ,       | Dialing paused for amount of time specified |
          |              | in S8 register                              |
          |--------------+---------------------------------------------|
          |      !       | Modem commanded to go off-hook for          |
          |              | specified time before returning on-hook.    |
          |--------------+---------------------------------------------|
          |      @       | Wait for quiet answer                       |
          |--------------+---------------------------------------------|
          |      ;       | Modem returned to command state after       |
          |              | dialing                                     |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                     REPORT INFORMATION                     |
          |------------------------------------------------------------|
          | Type:        | Immediate                                   |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] In [cmds]                         |
          |--------------+---------------------------------------------|
          | Description: | Displays information requested              |
          |--------------+---------------------------------------------|
          |   Command    |                  Function                   |
          |--------------+---------------------------------------------|
          |      I0      | Reports product code                        |
          |--------------+---------------------------------------------|
          |      I1      | Reports ROM checksum                        |
          |--------------+---------------------------------------------|
          |      I2      | Tests and reports ROM checksum              |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                 BUFFER SIZE - LOWER LIMIT                  |
          |------------------------------------------------------------|
          | Type:        | Register                                    |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] S49=n [cmds]                      |
          |--------------+---------------------------------------------|
          | Default:     | 8                                           |
          |--------------+---------------------------------------------|
          | Range:       | 1-249                                       |
          |--------------+---------------------------------------------|
          | Unit:        | 1 byte                                      |
          |--------------+---------------------------------------------|
          | Description: | Controls the low-end size of the buffer     |
          |              | during error-control or auto-speed          |
          |              | buffering mode                              |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                 BUFFER SIZE - UPPER LIMIT                  |
          |------------------------------------------------------------|
          | Type:        | Register                                    |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] S50=n [cmds]                      |
          |--------------+---------------------------------------------|
          | Default:     | 16                                          |
          |--------------+---------------------------------------------|
          | Range:       | 2-250                                       |
          |--------------+---------------------------------------------|
          | Unit:        | 1 byte                                      |
          |--------------+---------------------------------------------|
          | Description: | Controls the high-end size of the buffer    |
          |              | during error-control or auto-speed          |
          |              | buffering mode                              |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |               LEASED LINE ATTENUATION LEVEL                |
          |------------------------------------------------------------|
          | Type        | Register                                     |
          |-------------+----------------------------------------------|
          | Format      | AT [cmds] S63=n [cmds]                       |
          |-------------+----------------------------------------------|
          | Default     | 0                                            |
          |-------------+----------------------------------------------|
          | Range       | 0-15                                         |
          |-------------+----------------------------------------------|
          | Unit        | -1 dBm                                       |
          |-------------+----------------------------------------------|
          | Description | Sets the power level for transmission over   |
          |             | leased lines                                 |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                        FRAME LIMIT                         |
          |------------------------------------------------------------|
          | Type         | Register                                    |
          |--------------+---------------------------------------------|
          | Format       | AT [cmds] S69=n [cmds]                      |
          |--------------+---------------------------------------------|
          | Default:     | 15                                          |
          |--------------+---------------------------------------------|
          | Range:       | 0-15                                        |
          |--------------+---------------------------------------------|
          | Unit:        | 1 frame                                     |
          |--------------+---------------------------------------------|
          | Description: | Sets the maximum number of packets that may |
          |              | be sent without acknowledgment by the       |
          |              | remote system.                              |
          |--------------+---------------------------------------------|
          | Note:        | LAPM connections use a maximum of 15        |
          |              | frames. LAPB and X.25 connections use a     |
          |              | maximum of 8 frames.                        |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                   FRAME RE-TRANSMISSION                    |
          |------------------------------------------------------------|
          | Type         | Register                                    |
          |--------------+---------------------------------------------|
          | Format       | AT [cmds] S70=n [cmds]                      |
          |--------------+---------------------------------------------|
          | Default:     | 10                                          |
          |--------------+---------------------------------------------|
          | Range:       | 0-255                                       |
          |--------------+---------------------------------------------|
          | Unit:        | 1 frame                                     |
          |--------------+---------------------------------------------|
          | Description: | Sets the limit for the number of            |
          |              | re-transmissions the local modem attempts   |
          |              | when an error-control mechanism detects     |
          |              | frame transmission data errors. After the   |
          |              | re-transmission limit has been reached, the |
          |              | modem initiates the hang-up process.        |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                      LINK LAYER TIMER                      |
          |------------------------------------------------------------|
          | Type         | Register                                    |
          |--------------+---------------------------------------------|
          | Format       | AT [cmds] S71=n [cmds]                      |
          |--------------+---------------------------------------------|
          | Default:     | 2                                           |
          |--------------+---------------------------------------------|
          | Range:       | 1-255                                       |
          |--------------+---------------------------------------------|
          | Unit:        | .1 second                                   |
          |--------------+---------------------------------------------|
          | Description: | Sets the maximum duration the local modem   |
          |              | waits for a response after sending the link |
          |              | layer. If no response is received within    |
          |              | LINKLIMIT (see note), the local modem       |
          |              | re-transmits the link layer.                |
          |--------------+---------------------------------------------|
          | Note:        | The duration is determined according to the |
          |              | formula:                                    |
          |              |                                             |
          |              | LINKLIMIT = 2(maximum packet size + 11)(8 + |
          |              | line speed[bps]) + S71 + 500 ms             |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                      FLAG IDLE TIMER                       |
          |------------------------------------------------------------|
          | Type         | Register                                    |
          |--------------+---------------------------------------------|
          | Format       | AT [cmds] S72=n [cmds]                      |
          |--------------+---------------------------------------------|
          | Default:     | 30                                          |
          |--------------+---------------------------------------------|
          | Range:       | 1-255                                       |
          |--------------+---------------------------------------------|
          | Unit:        | 1 second                                    |
          |--------------+---------------------------------------------|
          | Description: | Sets the maximum duration the modem waits   |
          |              | after detecting loss of both data and       |
          |              | flag-idle signals. When the maximum         |
          |              | duration is reached, the modem initiates    |
          |              | the hang-up process. A value of 0 in S72    |
          |              | allows an indefinite wait.                  |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                      DATA LOSS TIMER                       |
          |------------------------------------------------------------|
          | Type         | Register                                    |
          |--------------+---------------------------------------------|
          | Format       | AT [cmds] S73=n [cmds]                      |
          |--------------+---------------------------------------------|
          | Default:     | 5                                           |
          |--------------+---------------------------------------------|
          | Range:       | 1-255                                       |
          |--------------+---------------------------------------------|
          | Unit:        | 1 second                                    |
          |--------------+---------------------------------------------|
          | Description: | Sets the maximum duration the modem waits   |
          |              | after detecting loss of data while          |
          |              | receiving good carrier and flag idle        |
          |              | signals. When the maximum duration is       |
          |              | reached, the local modem sends a query to   |
          |              | the remote modem to determine if it is      |
          |              | operating properly. When the value          |
          |              | calculated for QUERYLIMIT is reached (see   |
          |              | note), the modem initiates the hang-up      |
          |              | process.                                    |
          |--------------+---------------------------------------------|
          | Note:        | The local modem will send the query several |
          |              | times according to the formula:             |
          |              |                                             |
          |              | QUERYLIMIT= 2(LINKLIMIT)(S73) seconds       |
          |              |                                             |
          |              | The value for LINKLIMIT is defined in S71.  |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                      ASU NEGOTIATION                       |
          |------------------------------------------------------------|
          | Type         | Register                                    |
          |--------------+---------------------------------------------|
          | Format       | AT [cmds] S84=n [cmds]                      |
          |--------------+---------------------------------------------|
          | Description: | Sets the Adaptive Start-Up (ASU)            |
          |              | negotiation method                          |
          |--------------+---------------------------------------------|
          |   Command    |                  Function                   |
          |--------------+---------------------------------------------|
          |    S84=0     | ASU disabled                                |
          |--------------+---------------------------------------------|
          |   S84=128    | Fixed startup                               |
          |--------------+---------------------------------------------|
          |  í S84=129   | Both local and remote modems use fast       |
          |              | startup                                     |
          |--------------+---------------------------------------------|
          |   S84=130    | Both local and remote modems use smooth     |
          |              | startup                                     |
          |--------------+---------------------------------------------|
          |   S84=131    | Local modem uses fast startup, remote uses  |
          |              | smooth startup                              |
          |--------------+---------------------------------------------|
          |   S84=132    | Local modem uses smooth startup, remote     |
          |              | uses fast startup                           |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                   ASU NEGOTIATION REPORT                   |
          |------------------------------------------------------------|
          | Type         | Register                                    |
          |--------------+---------------------------------------------|
          | Format       | AT [cmds] S85? [cmds]                       |
          |--------------+---------------------------------------------|
          | Description: | Reports the Adaptive Start-Up (ASU)         |
          |              | negotiation method                          |
          |--------------+---------------------------------------------|
          |    Value     |                   Meaning                   |
          |--------------+---------------------------------------------|
          |      0       | ASU disabled                                |
          |--------------+---------------------------------------------|
          |     128      | Fixed startup                               |
          |--------------+---------------------------------------------|
          |    í 129     | Both local and remote modems use fast       |
          |              | startup                                     |
          |--------------+---------------------------------------------|
          |     130      | Both local and remote modems use smooth     |
          |              | startup                                     |
          |--------------+---------------------------------------------|
          |     131      | Local modem uses fast startup, remote uses  |
          |              | smooth startup                              |
          |--------------+---------------------------------------------|
          |     132      | Local modem uses smooth startup, remote     |
          |              | uses fast startup                           |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                           MI/MIC                           |
          |------------------------------------------------------------|
          | Type         | Register                                    |
          |--------------+---------------------------------------------|
          | Format       | AT [cmds] S92=n [cmds]                      |
          |--------------+---------------------------------------------|
          | Description: | Controls the Mode Indicate/Mode Indicate    |
          |              | Common (MI/MIC) interface.                  |
          |--------------+---------------------------------------------|
          |   Command    |                  Function                   |
          |--------------+---------------------------------------------|
          |   í S92=0    | MI/MIC disabled                             |
          |--------------+---------------------------------------------|
          |    S92=1     | Level triggered, originate mode, ring       |
          |              | indicator pulse enabled                     |
          |--------------+---------------------------------------------|
          |    S92=3     | Edge triggered, originate mode, ring        |
          |              | indicator pulse enabled                     |
          |--------------+---------------------------------------------|
          |    S92=5     | Level triggered, answer mode, ring          |
          |              | indicator pulse enabled                     |
          |--------------+---------------------------------------------|
          |    S92=7     | Edge triggered, answer mode, ring indicator |
          |              | pulse enabled                               |
          |--------------+---------------------------------------------|
          |    S92=9     | Level triggered, originate mode, ring       |
          |              | indicator pulse disabled                    |
          |--------------+---------------------------------------------|
          |    S92=11    | Edge triggered, originate mode, ring        |
          |              | indicator pulse disabled                    |
          |--------------+---------------------------------------------|
          |    S92=13    | Level triggered, answer mode, ring          |
          |              | indicator pulse disabled                    |
          |--------------+---------------------------------------------|
          |    S92=15    | Edge triggered, answer mode, ring indicator |
          |              | pulse disabled                              |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                     V.25bis DTE SPEED                      |
          |------------------------------------------------------------|
          | Type         | Register                                    |
          |--------------+---------------------------------------------|
          | Format       | AT [cmds] S93=n [cmds]                      |
          |--------------+---------------------------------------------|
          | Description: | Sets the speed of the local serial port     |
          |              | when in V.25bis mode.                       |
          |--------------+---------------------------------------------|
          |   Command    |                  Function                   |
          |--------------+---------------------------------------------|
          |    S93=3     | 300bps                                      |
          |--------------+---------------------------------------------|
          |    S93=5     | 1200bps                                     |
          |--------------+---------------------------------------------|
          |    S93=6     | 2400bps                                     |
          |--------------+---------------------------------------------|
          |    S93=7     | 4800bps                                     |
          |--------------+---------------------------------------------|
          |   í S93=9    | 9600bps                                     |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                    COMMAND SET OPTIONS                     |
          |------------------------------------------------------------|
          | Type         | Register                                    |
          |--------------+---------------------------------------------|
          | Format       | AT [cmds] S94=n [cmds]                      |
          |--------------+---------------------------------------------|
          | Default:     | 0                                           |
          |--------------+---------------------------------------------|
          | Range:       | 0-15                                        |
          |--------------+---------------------------------------------|
          | Unit:        | Bit-mapped                                  |
          |--------------+---------------------------------------------|
          | Description: | Sets various options for command set modes  |
          |--------------+---------------------------------------------|
          | Bit  | Value |                  Function                   |
          |------+-------+---------------------------------------------|
          | 1, 0 |    00 | Use AT command set                          |
          |      |       |                                             |
          |      |    01 | Use asynchronous V.25 command set           |
          |      |       |                                             |
          |      |    10 | Use synchronous V.25 command set with HDLC  |
          |      |       | framing                                     |
          |      |    11 |                                             |
          |      |       | Use synchronous V.25 command set with       |
          |      |       | character framing                           |
          |------+-------+---------------------------------------------|
          |  2   |     0 | Addressed calling                           |
          |      |       |                                             |
          |      |     1 | Direct access calling                       |
          |------+-------+---------------------------------------------|
          |  3   |     0 | Use ASCII character set                     |
          |      |       |                                             |
          |      |     1 | Use EBCDIC character set                    |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                     PAD CONFIGURATION                      |
          |------------------------------------------------------------|
          | Type:        | Register                                    |
          |--------------+---------------------------------------------|
          | Format:      | AT [cmds] S53=n [cmds]                      |
          |--------------+---------------------------------------------|
          | Description: | Sets various options for the X.25 Packet    |
          |              | Assembler/Disassembler.                     |
          |------------------------------------------------------------|
          |    Command    |                  Function                  |
          |---------------+--------------------------------------------|
          |     S53=0     | CCITT compatibility                        |
          |---------------+--------------------------------------------|
          |     S53=1     | CCITT compatibility, display channel       |
          |               | number before PAD prompt ( 1* )            |
          |---------------+--------------------------------------------|
          |    í S53=2    | Fixed user interface, PAD prompt hyphen (  |
          |               | - )                                        |
          |---------------+--------------------------------------------|
          |     S53=3     | Fixed user interface, display channel      |
          |               | number before PAD prompt ( 1- )            |
          |---------------+--------------------------------------------|
          |     S53=4     | Fixed control interface, PAD prompt hyphen |
          |---------------+--------------------------------------------|
          |     S53=5     | Fixed control interface, display channel   |
          |               | number before PAD prompt                   |
          |---------------+--------------------------------------------|
          |     S53=6     | Fixed user and fixed control interface,    |
          |               | PAD prompt hyphen                          |
          |---------------+--------------------------------------------|
          |     S53=7     | Fixed user and fixed control interface,    |
          |               | display channel number before PAD prompt   |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                    MINIMUM INCOMING LCN                    |
          |------------------------------------------------------------|
          | Type         | Register                                    |
          |--------------+---------------------------------------------|
          | Format       | AT [cmds] S74=n S75=n [cmds]                |
          |--------------+---------------------------------------------|
          | Default:     | 0 (S74), 0 (S75)                            |
          |--------------+---------------------------------------------|
          | Range:       | 1-40 (S74), 1-99 (S75)                      |
          |--------------+---------------------------------------------|
          | Unit:        | None                                        |
          |--------------+---------------------------------------------|
          | Description: | These registers set the lowest Logical      |
          |              | Channel Number (LCN) that the packet driver |
          |              | will attempt to answer calls on. The        |
          |              | address itself may range from 0 - 4095.     |
          |--------------+---------------------------------------------|
          | Note:        | The address is determined by the formula:   |
          |              |                                             |
          |              | ADDRESS = S74 * 100 + S75                   |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                    MAXIMUM INCOMING LCN                    |
          |------------------------------------------------------------|
          | Type         | Register                                    |
          |--------------+---------------------------------------------|
          | Format       | AT [cmds] S76=n S77=n [cmds]                |
          |--------------+---------------------------------------------|
          | Default:     | 40 (S76), 95 (S77)                          |
          |--------------+---------------------------------------------|
          | Range:       | 1-40 (S76), 1-99 (S77)                      |
          |--------------+---------------------------------------------|
          | Unit:        | None                                        |
          |--------------+---------------------------------------------|
          | Description: | These registers set the highest Logical     |
          |              | Channel Number (LCN) that the packet driver |
          |              | will attempt to answer calls on. The        |
          |              | address itself may range from 0 - 4095.     |
          |--------------+---------------------------------------------|
          | Note:        | The address is determined by the formula:   |
          |              |                                             |
          |              | ADDRESS = S76 * 100 + S77                   |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                        OUTGOING LCN                        |
          |------------------------------------------------------------|
          | Type         | Register                                    |
          |--------------+---------------------------------------------|
          | Format       | AT [cmds] S78=n S79=n [cmds]                |
          |--------------+---------------------------------------------|
          | Default:     | 0 (S78), 16 (S79)                           |
          |--------------+---------------------------------------------|
          | Range:       | 1-40 (S78), 1-99 (S79)                      |
          |--------------+---------------------------------------------|
          | Unit:        | None                                        |
          |--------------+---------------------------------------------|
          | Description: | These registers set the Logical Channel     |
          |              | Number (LCN) that the packet driver will    |
          |              | place calls on. The address itself may      |
          |              | range from 0 - 4095.                        |
          |--------------+---------------------------------------------|
          | Note:        | The address is determined by the formula:   |
          |              |                                             |
          |              | ADDRESS = S78 * 100 + S79                   |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                      RESTART REQUEST                       |
          |------------------------------------------------------------|
          | Format       | AT [cmds] S80=n [cmds]                      |
          |--------------+---------------------------------------------|
          | Default:     | 1                                           |
          |--------------+---------------------------------------------|
          | Range:       | 0-255                                       |
          |--------------+---------------------------------------------|
          | Unit:        | None                                        |
          |--------------+---------------------------------------------|
          | Description: | Sets the maximum number of retransmission   |
          |              | requests                                    |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                 ACKNOWLEDGMENT WAIT TIMER                  |
          |------------------------------------------------------------|
          | Type:        | Register                                    |
          |--------------+---------------------------------------------|
          | Format       | AT [cmds] S81=n [cmds]                      |
          |--------------+---------------------------------------------|
          | Default:     | 18                                          |
          |--------------+---------------------------------------------|
          | Range:       | 0-255                                       |
          |--------------+---------------------------------------------|
          | Unit:        | 10 seconds                                  |
          |--------------+---------------------------------------------|
          | Description: | Maximum time the modem will wait for        |
          |              | acknowledgment of a request for             |
          |              | retransmission before it initiates          |
          |              | recovery.                                   |
          +------------------------------------------------------------+