Black Box 32144, Manual

Page: 186 / 195

34
MODEM 32144
Fig. 2-4. A Typical Multidrop Configuration.
S
LAVE
-
TO
-M
ASTER
(I
NBOUND
)
T
RANSMISSION
When the remote modems come
on-line, they automatically synch-
ronize to the incoming carrier and
train on the data stream from the
master modem. Slave-to-master
transmission is always switched
carrier operation under control
of the RTS signal from the DTE.
An anti-streaming timer built into
the modem will (if enabled) halt
transmission if the DTE holds RTS
on for more than 30 seconds. The
assumption is that if RTS is held on
for more than 30 seconds, there is
a fault in the DTE.
NOTE
See page 176 (pump 3)
to enable anti-streaming.
The V.29 Fast Master and Fast
Slave modes support sync data rates
of 4800, 7200, and 9600 bps and an
async data rate of 9600 bps only.
The leased lines can be conditioned
or unconditioned. The master
modem must be set to originate
mode, and the slave modem
must be set to answer mode.
(The Answer/Originate option is
automatically set to these settings
when the V.29 Fast Master and Fast
Slave Quick Setups are used.)
NOTE
If you’re using V.29
master/slave async in an
unmanned location, call
Black Box Tech Support at
724-746-5500.