Omron DeviceNet Safety, System Configuration Manual

Page: 328 / 376

294
Appendix A
There are two methods for allocation.
Examples of allocation are as follows:
Allocation when outputs or inputs are as shown below
#00 1 byte
#01 2 bytes
#02 1 byte
#03 4 bytes
#04 1 byte
#05 1 byte
Allocation by Word
Allocation Minimizing the Number of Allocated Words
Allocate each device by channel Each slave is always allocated the low byte (lower 7 bits)
of the word. Therefore, each slave is allocated one word
even if 1-byte I/O slaves come sequentially.
Example:
Allocate so that the total number
of allocated words is minimized
(two devices may be allocated to
one word) If there are 1-byte I/O slaves, allocation is in the order of
low byte (lower 7 bits) to high byte (upper 7 bits) to create
as few unused areas as possible.
Example:
High Low
15 8 7
0
+0 word #00
+1 word #01
+2 word #02
+3 word #03
+4 word #03
+5 word #04
+6 word #05
High Low
15 8 7 0
+0 word #00
+1 word #01
+2 word #02
+3 word #03
+4 word #05 #04
#0
#1
… … 0 7 8 15
High Low
#3
#4
Node address order
Unused
#6
#0
#1
… … 0 7 8 15
High Low
#3
#4
#6
Node address
order
Unused