Omron CS1D DUPLEX SYSTEM - 10-2009 Operation Manual page 292

I/O Memory Areas
Link Area
CPU Bus Unit Area
Special I/O Unit Area
Inner Board Area
CS-series DeviceNet Area
Internal I/O Area
Work Area (WR)
Holding Area (HR)
256
Words in the Link Area are used for data links when LR is set as the data link
area for automatic allocation for Controller Link Networks. It is also used for
PLC Links. Words in the Link Area can be used in the program when LR is not
set as the data link area for Controller Link Networks and PLC Links are not
used.
These words are allocated to CPU Bus Units to transfer status information.
Each Unit is allocated 25 words and up to 16 Units (with unit numbers 0 to 15)
can be used. Words that aren't used by CPU Bus Units may be used only in
the program.
These words are allocated to Special I/O Units. Each Unit is allocated 10
words and up to 96 Units (unit numbers 0 to 95) can be used.
Words that aren't used by Special I/O Units may be used only in the program.
These words are allocated to Inner Boards such as Communications Boards.
Up to 100 words can be allocated for input and output.
Note The Inner Board Area is used for Inner Boards only in Single CPU Systems or
for the Inner Boards in a Process-control CPU Units in Duplex CPU Systems.
These words are allocated to Slaves for DeviceNet Remote I/O Communica-
tions for CS-series DeviceNet Units (CS1W-DRM21). Allocations are fixed
and cannot be changed. Be sure that allocates to not overlap with those used
for other I/O points.
These words can be used only in the program; they cannot be used for I/O
exchange with external I/O terminals. Be sure to use the work words provided
in the Work Area (WR) before allocating words in the Internal I/O Area or
other unused words in the CIO Area. It is possible that these words will be
assigned to new functions in future versions of CS1D CPU Units, so the pro-
gram may have to be changed before being used in a new CS1D PLC if CIO
Area words are used as work words in the program.
Words in the Work Area can be used only in the program; they cannot be
used for I/O exchange with external I/O terminals. No new functions will be
assigned to this area in future versions of CS1D PLCs, so use this area for
work words and bits before any words in the CIO Area.
Words in the Holding Area can be used only in the program. 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.
Word
15
W511
Section 8-2
Bit