Omron SYSMAC CS1W-SCB41-V1 Operation Manual page 42

Features
Computer Monitoring and
Control of PLCs
FINS Commands for
Complete Control
Redundant Error
Checking
Simultaneous Usage of
Both Ports
Slave-initiated
Communications
Send FINS Commands to
Remote Networks
Send FINS Commands to
Computers Connected to
Remote PLCs
Host Link communications enable the host computer to monitor or control
PLC operations and to read and write I/O memory in the PLCs.
In addition to C-series (Host Link) commands, FINS commands are also sup-
ported. FINS commands give you the power to control CS/CJ-series PLC
functionality.
Both vertical and horizontal (FCS) parity checks are performed on communi-
cations data to achieve essentially error-free communications. Combining
error checking and retry processing goes one step further to eliminate nearly
all the effects of communications problems.
Each Serial Communications Board and Unit provides two serial ports that
can be used simultaneously to connect to two different host computers. A total
of up to 16 CPU Bus Units, including the Serial Communications Units, can be
mounted to one PLC. If all 16 CPU Bus Units are Serial Communications
Units, then up to 32 ports can be added.
Communications can be performed either by sending a command from a host
computer and having the PLC return a response, or by sending a command
from a PLC and having the computer send a response. Starting communica-
tions from a slave is called unsolicited communications, and is made possible
through the SEND(090), RECV(098), and CMND(490) instructions. These
can be used to send FINS commands to a host computer connected locally or
to a host computer connected to a remote network up to three networks away
(counting the local network).
A FINS command contained within a Host Link header and terminator can be
sent using Host Link communications to PLCs connected not only on Host
Link networks, but also other interconnected remote networks up to three net-
works away (counting the local network). Various types of networks can exist
between the source of the command and the destination of the command.
Host Link
Controller Link Network
A FINS command contained within a Host Link header and terminator can be
sent using Host Link communications to a host computer connected to a PLC
on a remote network up to three networks away (counting the local network,
but not counting the final Host Link connection). Various types of networks
can exist between the PLC sending the command and the destination of the
command.
Bridge
Controller Link Network
Section 1-4
Ethernet Network
Gateway
13