Allen-Bradley 1779-KFMR User Manual page 199

Appendix B
In Figure B.1, the Level 4 address is 260 (decimal), which is too large to
fit in one byte. Therefore, a byte of all ones is used to delimit the
two-byte address field for this level. The value 260 is then coded low
byte first. Note that the last level (Level 6 in this case) must be specified
in the address field even though it is equal to the default value of zero.
Figure B.1
Example of PLC 3 Logical Addressing
PLC 3 Extended Addressing
Logical Addressing Format
6 5
0 0 1 1
0 0 0 0
1 1 1 1
0 0 0 0
0 0 0 0
0 0 0 0
4 3 2 1
0 1 0 0
0 0 1 0
1 1 1 1
>
0 1 0 0
0 0 0 1
0 0 0 0
Current Context