Hi Duilio,

    I've connected 2 modems directly without going
    through a phoneline. You don't have to supply
    the telephone line dc voltage as well as most
    PC modems is already self powered.

    The trick is to get the modem to dial without
    detecting a dial tone.
    Using modem AT commands, you can disable dial tone
    checking by sending the command ATX3

    Just ATX3 the dialing modem, then ATD.
    Send ATA to the receiving modem to answer.

    They will start negotiation and connect without
    any problem.

    If you still need the dial-tone, you can easily
    generate one using a NE555N at around 400Hz~450Hz
    and feed them (via resistor) to the TIP signal line.

Regards,
Peter Tiang

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----- Original Message -----
From: "Duilio Foschi" <foschid@SHUTTLE.ETRURIA.NET>
To: <PICLIST@MITVMA.MIT.EDU>
Sent: Thursday, December 09, 1999 11:35 PM
Subject: communication btw 2 modems


> can 2 modems communicate w/o supplying the canonic 30 volts to the
> connecting copper pair ?
>
> If not, why not ?
>
> Thank you
>
> Duilio Foschi
>