431
Battery-free Operation
Section 8-5
8-5
Battery-free Operation
8-5-1
Overview
With the CP1L-EL/EM CPU Unit, saving backup data in the built-in flash mem-
ory (non-volatile memory) enables operation with no battery mounted (i.e.,
battery-free operation).
I/O memory (such as CIO), however, is constantly refreshed during operation,
so backup data is not saved in the built-in flash memory. When battery-free
operation is used, therefore, programs must be created assuming that I/O
memory data will not be saved.
For example, if a battery is mounted, then HR, CNT, and DM data is saved
during power interruptions if a battery is mounted but not when battery-free
operation is used.
In that case it is necessary to set the required values in the ladder program. It
is also possible to save to the built-in flash memory in advance the DM initial
values that are to be set for the DM on RAM at startup.
8-5-2
Using Battery-free Operation
Precautions when
Creating Programs
for Battery-free
Operation
Be careful of the following points, and create programs for which it will not be
a problem even if the correct I/O memory values are not held.
• For unstable parts of I/O memory, include programming at the start of
operation to set required data.
• When battery-free operation is used, the Output OFF Flag (A500.15) in
the Auxiliary Area becomes unstable. When the Output OFF Flag turns
ON, all outputs turn OFF, so include the following program for clearing the
Output OFF Flag at the start of operation.
• Do not reference the clock function, (the clock data in words A351 to A354
of the Auxiliary Area, or the various kinds of time data).
Saving DM Initial
Values (Only when
Required)
Use the following procedure to save to the built-in flash memory the DM initial
values that are to be set at startup.
1,2,3...
1.
First set in the DM Area the data that is to be set as initial values at startup.
2.
Execute a backup to flash memory from the CX-Programmer's Memory
Cassette Transfer/Data Memory Backup Dialog Box.
The procedure is as follows:
a.
Select PLC - Edit - Memory Cassette/DM.
The following Memory Cassette Transfer/DM Backup Dialog Box will
be displayed.
RSET
A500.15
A200.11
First Cycle Flag
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: ......