Addressing, Data encoding and addressing chapter 6 – Rockwell Automation 1770-KF2 Data Highway or Highway Plus Interface Module User Manual User Manual
Page 145
Data Encoding and Addressing
Chapter 6
6-8
Figure 6.6
Results of Transmitting Low Byte First
17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00
1
0
0
1
1
0
0
1
0
1
1
1
0
1
1
0
Value
Bit Number
(Octal)
A576 Hex
Odd, High Byte
Even, Low Byte
PC Word
A.
15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
1
0
0
1
1
0
0
1
0
1
1
1
0
1
1
0
Value
Bit Number
(Decimal)
A576 Hex
Odd, High Byte
Even, Low Byte
16-Bit Computer Word with Right-to-Left Byte and Bit Order
B.
00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15
0
1
0
1
1
1
1
0
1
0
1
0
0
1
0
1
Value
Bit Number
(Decimal)
A576 Hex
Even, High Byte
Odd, Low Byte
16-Bit Computer Word with Left-to-Right Byte and Bit Order
C.
15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
0
1
0
1
1
1
1
0
1
0
1
0
0
1
0
1
Value
Bit Number
(Decimal)
A576 Hex
Even, High Byte
Odd, Low Byte
16-Bit Computer Word with Left-to-Right Byte Order and Right-to-Left Bit Order
D.
(after Byte
Swapping)
(after Byte
Swapping)
11396
There are three types of addressing a computer can use in command
messages that it transmits to PC stations:
Logical
Physical
Symbolic
Logical Addressing
You use logical addressing in commands that access PLC data table
memory only (non-privileged commands). For example, you use logical
Addressing