Omron CJ - 09-2009 Operation Manual page 87

CJ1-H/CJ1M CPU Unit Ver. 2.0 Upgrades
Example Write Protection Patterns
Connection pattern
From a com- Direct con-
puter through nection to
a direct serial PLC
connection
Gateway con-
nection
(Serial-to-net-
work) to PLC
Computer #1
PLC #1
Network
Note This function prohibits writing by FINS commands only, so it has no effect on
write operations by functions other than FINS commands, such as data links.
Computer
Write-protection not effective
Serial connection
(Peripheral bus or
host link)
Computer
Serial connection
(Peripheral bus
or host link)
Write operations by FINS com-
mands are prohibited from some
nodes in the network (in this exam-
ple, computer #1, PLC #1, and
PLC #2).
Network
Write access to this PLC
is enabled/disabled.
Diagram (example)
Peripheral port
PLC
RS-232C port
RS-232C port or 422A/485 port
on a Communications Board/Unit
The CPU Unit in PLC #2
can be write-protected.
PLC #1
Network
Section 1-6
Computer #2
PLC #2 PLC #3
Network
Write operations by FINS com-
mands are not prohibited from
selected nodes in the network
(in this example, computer #2
and PLC #3).
Write
protection
Cannot be
applied.
Can be
applied.
PLC #2
39