Omron CP1L - 12-2007, Operation Manual

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Overview of I/O Memory Area
Section 4-1
Auxiliary Area (A) These words are allocated to specific functions in the system.
Refer to
Appendix C Auxiliary Area Allocations by Function and Appendix D
Auxiliary Area Allocations by Address for details on the Auxiliary Area.
Temporary Relay Area
(TR) The TR Area contains bits that record the ON/OFF status of program
branches. Refer to the
CP1H/CP1L Programming Manual for details.
Data Memory Area (D) The DM Area is a multi-purpose data area that is normally accessed only in
word-units. These words retain their content when the PLC is turned ON or
the operating mode is switched between PROGRAM mode and RUN or MON-
ITOR mode.
Timer Area (T) There are two parts to the Timer Area: the Timer Completion Flags and the
timer Present Values (PVs). Up to 4,096 timers with timer numbers T0 to
T4095 can be used.
Timer Completion Flags
These flags are read as individual bits. A Completion Flag is turned ON by the
system when the corresponding timer times out (i.e., when the set time
elapses).
Timer PVs
The PVs are read and written as words (16 bits). The PVs count up or down
as the timer operates.
Counter Area (C) There are two parts to the Counter Area: the Counter Completion Flags and
the Counter Present Values (PVs). Up to 4,096 counters with counter num-
bers C0 to C4095 can be used.
Counter Completion Flags
These flags are read as individual bits. A Completion Flag is turned ON by the
system when the corresponding counter counts out (i.e., when the set value is
reached).
A447
A448
A959
15
Read-write area
Read-only area
Word
Bit
D0
D32767
15
0
Bit
D0
D32767
15
0
Bit
D9999
D32000
CPU Unit with 14 or 20 I/O Points CPU Unit with 30 or 40 I/O Points