Technical information
2.3 Communications Options
The
VAX
4000 Model 300
system
supports
the
following communications
options:
• CXA16 asynchronous
multiplexer
(16 lines)
• CXB16 asynchronous
multiplexer
(16 lines)
• CXY08 asynchronous
multiplexer
(8 lines)
• DESQA
Ethernet
controller
• DFAOI asynchronous controller
with
integral
modem
•
DPVll
synchronous interface
• DSRVB DECserver 200
•
DSVll
synchronous controller
Asynchronous
Serial
Controllers
Asynchronous serial controllers provide low-speed connections between
peripheral
devices
and
the
system. Asynchronous communications between
the
system
and
the
peripheral
depends
on recognition
of
a
pattern
of
start
and
stop bits,
not
on
a
time
interval.
Synchronous
Serial
Controllers
Synchronous
serial controllers provide high-speed connections between
systems. Communication
between
synchronous devices
depends
on
time
intervals
that
are
synchronized before
transmission
of
data
begins.
Ethernet
Controllers
Ethernet
controllers connect
your
system
to
an
Ethernet
network. With
a
network
connection
and
appropriate
DECnet
software, you
can
use
all
network
services.
2-24
VAX 4000 Model 300 Technical Information