ZOOM TELEPHONICS, INC.

VFX 28.8

Card Type                    Fax, Modem (asynchronous)
Chip Set                     Unidentified
Maximum Data Rate            28.8Kbps
Maximum Fax Rate             14.4Kbps
Data Bus                     External
Fax Class                    Unidentified
Data Modulation Protocol     Unidentified
Fax Modulation Protocol      Unidentified
Error Correction/Compression Unidentified

                                                                      V2022

                                CONNECTIONS

         Function           Label             Function             Label

  Line out                       CN1       DC power                 CN4

  Line in                        CN2       Power switch             SW1

  RS-232/422                     CN3

     MISCELLANEOUS TECHNICAL NOTES
           Note: Diagram not available.

                             DIAGNOSTIC LED(S)

    LED       Color      Status                  Condition

    MSG        Red         On       Used by software applications. Faxes
                                                are waiting

    MSG        Red        Off       Used by software applications. Faxes
                                              are not waiting

    FAX        Red         On          Modem is connected in FAX mode

    FAX        Red        Off        Modem is not connected in FAX mode

   28.8        Red         On           Modem connected at 28.8Kbps

   28.8        Red        Off         Modem not connected at 28.8Kbps

    VFC        Red         On            Modem connected using V.FC

    VFC        Red        Off          Modem not connected using V.FC

   14.4        Red         On        Modem connected at 14.4Kbps (V.FC,
                                           V.32bis, or FAX mode)

   14.4        Red        Off          Modem not connected at 14.4Kbps
                                        (V.FC, V.32bis, or FAX mode)

    DC         Red         On        Data compression (V.42bis or MNP5)
                                                  enabled

    DC         Red        Off        Data compression (V.42bis or MNP5)
                                                  disabled

    EC         Red         On          Error correction (V.42 or MNP4)
                                                  enabled

    EC         Red        Off          Error correction (V.42 or MNP4)
                                                  disabled

    FC         Red         On       Flow control enabled and data buffers
                                                  not full

    FC         Red        Off       Flow control disabled or data buffers
                                                    full

    AA         Red         On               Auto-answer enabled

    AA         Red        Off               Auto-answer disabled

    AA         Red      Blinking              Phone is ringing

    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

                         Proprietary AT Command Set

               See document V2021 for a full command summary.