Omron SYSMAC CP Series, User Manual

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5-3
5 I/O Memory
CP2E CPU Unit Software User’s Manual(W614)
5-1 Over
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5-1-1 I/O Memor
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Areas
These areas can be used freely by the user.
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Work Area (W)
The Word Area is part of the internal memory of the CPU Unit. It is used in programming. Unlike the
input bits and output bits in the CIO Area, I/O to and from external devices is not refreshed for this
area.
Use this area for work words and bits before using any words in the CIO Area. These words should
be used first in programming because they will not be assigned to new functions in future versions of
CP2E CPU Units.
Refer to 5- 3 Work Area (W)
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Holding Area (H)
The Holding Area is part of the internal memory of the CPU Unit. It is used in programming. Unlike
the input bits and output bits in the CIO Area, I/O to and from external devices is not refreshed for
this area.
These words retain their content when the PLC is turned ON or the operating mode is switched
between PROGRAM mode and RUN or MONITOR mode.
Automatically retained in the built-in non-volatile RAM even if the power supply is interrupted.
Refer to 5-4 Holding Area (H)
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Data Memory Area (D)
This data area is used for general data storage and manipulation and is accessible only by word (16
bits).
These words retain their content when the PLC is turned ON or the operating mode is switched
between PROGRAM mode and RUN or MONITOR mode.
Specified words can be retained in the built-in Flash Memory using Auxiliary Area bits.
Automatically retained in the built-in non-volatile RAM even if the power supply is interrupted.
Refer to 5-5 Data Memory Area (D)
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Timer Area (T)
There are two parts to the Timer Area: the Timer Completion Flags and the timer Present Values
(PVs).
Up to 256 timers with timer numbers T0 to T255 can be used.
• Timer Completion Flags
Each Timer Completion Flag is accessed as one bit using the timer number.
A Completion Flag is turned ON when the set time of the timer elapses.
• Timer PVs
Each timer PV is accessed as one word (16 bits) using the timer number.
The PV increases or decreases as the timer operates.
Refer to 5-6 Timer Area (T)
User Areas