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Battery-free Operation Section 6-4
Individually Displaying 7-segment LED Segments and Dots
Any code can be displayed by using SCTRL(048) to turn ON the bits corre-
sponding to individual segments and dots.
Clearing the 7-segment LED Display
Setting #0000 for SCTRL(048) and executing the instruction clears the entire
user-defined 7-segment LED display.
6-4 Battery-free Operation
6-4-1 Overview
With the CP1H CPU Unit, saving backup data in the built-in flash memory
(non-volatile memory) enables operation with no battery mounted (i.e., bat-
tery-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.
6-4-2 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.
Left digit Right digit
D200
7678
Displays data.
Displays "H."
Dis
la
ed "t."
SCTRL (048)
D200
W0.02
15 14 13 12 11 10 09 08
01
110110
7
6
Bit 13
Bit 14
Bit 12
Bit 11
Bit 8
Bit 9
Bit 10
Bit 15
Bit
Contents
07 06 05 04 03 02 01 00
01
111000
7
6
Bit 5
Bit 6
Bit 4
Bit 3
Bit 0
Bit 1
Bit 2
Bit 7
Bit
Contents
Clears the LED display
(all segments and dots).
W0.03
SCTRL (048)
#0000
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