Omron CP1L - 12-2007, Operation Manual

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64
CP1L CPU Unit Operation
Section 2-3
Routing Tables Tables specifying the communications paths from the Communications Units
on the local PLC to remote PLCs connected on other networks must be regis-
tered in all the CPU Units in network PLCs to send and receive data between
networks. These tables are called the routing tables. The routing tables con-
sist of the relay network table and local network table.
Routing tables are created from the CX-Programmer or Support Software for
Communications Units (e.g., CX-Integrator) and then transferred to each CPU
Unit.
Remote Network Table
The remote network tables lists the node number and network address of the
first relay node that must be passed through to reach any remote network to
which the PLC is not directly connected. Once the routing tables have been
registered, any remote network can be reached by passing through relay
nodes.
Local Network Table
The local network table contains the unit number and network address of all
Communications Units that are part of the local PLC.
Built-in Flash Memory
Flash memory is built into the CP1L CPU Units. Data in the following areas is
automatically backed up to the flash memory whenever it is written in any way
other than by instructions in the user program, e.g., when the CX-Programmer
or PT is used to transfer or edit data, edit the program online, or transfer data
from a Memory Cassette.
• User program area
• Parameter area (PLC Setup and routing tables)
The next time the power supply is turned ON, the data in the built-in flash
memory is automatically transferred to user memory (i.e., the user program
area and parameter area).
It is also possible to save data from data areas in I/O memory in the built-in
flash memory using operations from the CX-Programmer.
The symbol table, comment file, and program index file can be stored in the
comment memory in flash memory. When the program is transferred from the
CX-Programmer to the CPU Unit, function block program information is also
stored automatically in flash memory.
Note The BKUP indicator on the front of the CPU Unit will light whenever the built-in
flash memory is being written or the Memory Cassette is being accessed.
3 N
3 M
PLC 1
PLC 2 PLC 3
PLC 4
3
1
2
n
Node M
Unit number n
Network 1
Network 2
Network 3
Node N
Relay Network Table for PLC 1
Relay Network Table for PLC 2
Local Network Table for PLC 3
Remote
network
Relay
network Relay
node
Remote
network Relay
network Relay
node
Local
network
Unit
number