Omron SYSMAC CJ1W-SCU21-V1, Operation Manual

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13
Features Section 1-4
Computer Monitoring and
Control of 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.
FINS Commands for
Complete Control 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.
Redundant Error
Checking 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.
Simultaneous Usage of
Both Ports 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.
Slave-initiated
Communications 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).
Send FINS Commands to
Remote Networks 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.
Send FINS Commands to
Computers Connected to
Remote PLCs 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.
Host Link
Controller Link Network
Bridge
Controller Link Network
Gateway
Ethernet Network