Omron CJ1G-CPU series, Programming Manual

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Battery-free Operation Section 6-10
6-10 Battery-free Operation
The CS-series and CJ-series PLCs can be operated without a Battery
installed (or with an exhausted Battery). The procedure used for battery-free
operation depends on the following items.
• CPU Unit
• Whether or not I/O memory (e.g., CIO Area) is maintained or not
• Whether or not the DM and EM Areas are initialized at startup
• Whether or not the DM and EM Areas are initialized from the user pro-
gram
The above differences are summarized in the following table.
Note 1. When using battery-free operation, disable detecting a low battery voltage
in the PLC Setup regardless of the method used for battery-free operation.
2. If a Battery is not connected or the Battery is exhausted, the following re-
strictions will apply to CPU Unit operation. This is true regardless of the
CPU Unit being used.
• The contents of I/O memory (including the HR, DM, and EM Areas)
may not be correctly maintained. Therefore, set the PLC Setup so that
the status of the I/O Memory Hold Flag (A50012) and the Forced Sta-
tus Hold Flag (A50013) are not maintained when power is turned ON.
• The clock function cannot be used. The clock data in A351 to A354
and the startup time in A510 and A511 will not be dependable. The
files dates on files written to the Memory Card from the CPU Unit will
also not be dependable.
• The following data will be all-zeros at startup: Power ON Time (A523),
Power Interruption Time (A512 and A513), and Number of Power In-
terruptions (A514).
• The Error Log Area in A100 to A199 will not be maintained.
• The current EM bank will always be 0 at startup.
• There will be no files left in the EM file memory at startup and the file
memory functions cannot be used. The EM file memory must be reset
in the PLC Setup and the EM file memory must be reformatted to use
it.
CS1-H, CJ1-H, or CJ1M CPU Units
Battery-free operation is possible for CS1-H, CJ1-H, or CJ1M CPU Units with
normal operation. The user program and parameter data are automatically
backed up to flash memory in the CPU Unit and are automatically restored
from flash memory at startup. In this case, the I/O memory will not be main-
tained and the DM and EM Areas must be initialized from the user program.
Battery-free operation is also possible for the CS1-H, CJ1-H, or CJ1M CPU
Units by automatically transferring data from a Memory Card at startup, just
CPU Unit Not maintaining I/O memory Maintaining I/O memory
No initializing DM and
EM Areas at startup
Initializing DM and EM Areas at startup
From user program Not from user program
CS1-H,
CJ1-H, or
CJ1M Use normal operation (using flash memory) or a
Memory Card. Use automatic transfer
from a Memory Card at
startup. (Turn ON pin 2
of DIP switch.) Not possible with any method.
A Battery must be installed.
CS1 or CJ1 Use automatic transfer from a Memory Card at
startup. (Turn ON pin 2 of DIP switch.)