46
CP1L-EL/EM CPU Unit Operation
Section 2-3
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-EL/EM 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.
Never turn OFF the power supply to the CPU Unit when the BKUP indicator is
lit.
Memory Cassette
Memory Cassettes can be used as required in system operation and mainte-
nance. For example, they can be used to save programs, data memory con-
tents, PLC Setup data, or I/O comments from the CX-Programmer. The
contents of a Memory Cassette can also be automatically transferred if
desired.
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
Summary of Contents for CP1L-EL20DR-D
Page 3: ...CP1L EL20D CP1L EM30D CP1L EM40D CP1L EL EM CPU Unit Operation Manual Produced July 2017...
Page 4: ...iv...
Page 10: ...x...
Page 22: ...xxii...
Page 34: ...xxxiv Software Licenses and Copyrights 7...
Page 192: ...158 Trial Operation and Debugging Section 5 3...
Page 250: ...216 Automatic Clock Adjustment and Specifying Servers by Host Name Section 6 7...
Page 666: ...632 Trouble Shooting Section 11 7...
Page 696: ...662 Standard Models Appendix A...
Page 805: ...771 Connections to Serial Communications Option Boards Appendix F Connecting to Unit...
Page 806: ...772 Connections to Serial Communications Option Boards Appendix F...
Page 836: ...802 PLC Setup Appendix G...
Page 838: ...804 TCP Status Transitions Appendix H...
Page 840: ...806 Ethernet Network Parameters Appendix I...
Page 842: ...808 Buffer Configuration CP1L EL EM Appendix J...
Page 844: ...810 Ethernet Specifications Appendix K...
Page 851: ...Index 817 work words 118 write protection 447...
Page 852: ...818 Index...
Page 854: ...820 Revision History...
Page 855: ......