Omron CS1W-LC001 Operation Manual page 218

Maintenance
1, 2, 3...
1, 2, 3...
Á
To back up and recover memory if a battery error occurs during normal
operation
Note 1 Before turning ON pin 2 on the DIP switch, transfer the function block data to
the flash memory using the CX-Process Tool. If the function block data is not
stored in flash memory, RAM data will be overwritten and deleted at startup.
Note 2 Do not turn OFF the power supply to the PC when data is being transferred
from RAM to flash memory. Data will not be transferred correctly if power is
turned OFF before the transfer operation is completed, and a database may
occur when the contents of flash memory are transferred to RAM (e.g.,
during automatic transfer at startup with DIP switch pin 2 turned ON). If this
happens, ITEM 094 in the System Common block will be set to FFFF and bit
04 of word n will turn ON. If a database error occurs, download the function
block data gain from the CX-Process Tool to RAM in the Loop Control Unit,
and then transfer the contents of RAM to flash memory.
Battery-free operation
Although the Loop Control Unit can be run off of RAM backed up with a
battery, battery-free operation is also possible when it is impossible or
undesirable to perform battery maintenance. For battery-free operation,
however, a cold start must be used (i.e., internal arithmetic memory will be
initialized at startup).
Use the following procedure for battery-free operation.
1. Transfer the contents of RAM to flash memory from the CX-Process Tool.
(Note: Unit operation will stop when transfer is started.)
2. Turn OFF the power supply to the PC.
3. Turn ON pin 2 of the DIP switch.
4. Turn ON the power supply to the PC.
The Loop Control Unit will transfer the contents of flash memory to RAM
before executing a cold start.
Every time the Loop Control Unit is started, the contents of flash memory will
be transferred to RAM, and then a cold start will be performed. (As long as
power to the Unit remains ON, a hot start can also be performed from the
CX-Process Tool or Monitor.
RAM backup and recovery for battery errors
If the function block data is stored in flash memory in advance, the contents
of RAM can be restored if it is lost as the result of a battery error. Use the
following procedure.
1. Transfer the contents of RAM to flash memory from the CX-Process Tool.
(Note: Unit operation will stop when transfer is started.)
2. Start operation with pin 2 on the DIP switch turned OFF.
Either a hot or a cold start can be performed and the function block data
in RAM will be used.
3. Continue normal operation, checking for battery errors and replacing the
battery as required.
4. If a database error occurs (bit 04 of word n turns ON) indicating that the
contents of RAM has been corrupted, perform steps 5 to 11 to restore the
contents of RAM and continue operation again.
Section 7-2
201