Mark Graham wrote:

>Key to getting it to work is:
>&B1     Fixed Serial Port Rate (DTC 19,200 max) When    configuring the
>modem with an attached  terminal,this serial port rate is set by the
>attached terminal. Whatever rate you "AT" with,         it sets at that
>rate. Check terminal config rate        first.
>&H0     Disable TX data flow control
>&I0     Disable XON/XOFF flow control RX data
>&R1     Ignore RTS
>&S1     DSR after dialing/DSR after answer tone

&B1 is not a good idea if there's no flow control enabled.  With this
setup, someone could dial in at 1200 baud, with the answering modem
communicating with the 3000 at 19200 - a LISTF,2 would generate a
reasonable amount of data here, sending the data to the modem 8 times
faster than the modem can get rid of it - a perfect place for flow
control, except that it's turned off.

For USR modems, I'd change Mark's setup slightly to:

AT&F    Factory Reconfig
ATB0C1E1F1Q0V1X1
AT&A1&B0&C0&D2&G0&H0&I0&K1&L0&M4&N0&P0&R1&S2&T4&X0&Y1
       ^  ^                                ^
ATS0=1S58=1S13=1
           ^^^^^
AT&W    Write to NVRam

&B0 runs in flex-speed mode, so the 3000 runs no faster than the
modem's connection speed.  &C0 and &S2 result in DCD and DSR being
high in the steady state, enabling dial-out should it be desired, but
will still let DSR drop upon line disconnect so sessions will be
dutifully aborted on hangup.  Setting register 13 to 1 (specifically
setting the low-order bit to 1) will cause the modem to perform a
power-on reset whenever DTR (from the DTC) drops, hopefully preventing
the modem from getting into any weird state.

BTW, after the AT&F, many of the above settings are already set
correctly.  The AT commands could be reduced to:

AT&FE1Q0V1&B0&C0&D2&S2&T4S0=1S58=1S13=1&W

The E1, Q0, V1 and S0=1 settings should be specified as their values
may be altered via DIP switch.

------------
Randy Medd
Telamon, Inc.