..\Manuals\RCI-200-SER
Page 5 of 12
SERIAL Communication Option:
The -SER communications option for the RCI series utilizes either an RS-232 or RS-485 link to
exchange the signal data between a host and its remote(s). There are three types of
Topologies
that
can be configured: 1) Point-to-Point, 2) Host-to-Multipoint and 3) PC-to-Multipoint
In a
Point-to-Point
topology one
host communicates with one remote.
The two exchange all their signals
with one another. The remote is
configured as remote #1 even
though it is the only remote in the
system.
In a
Host-to-Multipoint
topology
one host communicates to several
remotes. Each remote is assigned
an address (1,2,3, etc.) so that the
host may distinguish between them.
There may at most be as many
remotes as there are inputs &
outputs on the host.
For example, an RCI-200 system,
having two analog/contact inputs
and outputs, may communicate with
up to two remotes each having one analog/contact input and output. In this case all
#1 inputs and
outputs on the host correspond to the #1 inputs and outputs on remote #1
and all
#2 inputs and
outputs on the host correspond to the #1 inputs and outputs on remote #2
.
In a
PC-to-Multipoint
topology one
PC (or PLC) host communicates
with one or more remotes via
MODBUS ASCII protocol. Software
that runs on the PC (or PLC) takes
the place of the Host and can
directly read and write the inputs and
outputs of the remote units. Each
remote is assigned an address
(1,2,3, etc.) so that the host may
distinguish between them.
