Rockwell Automation 1770, D17706.5.16 Ref Mnl DF1 Protocol Command - Manual (Page 198)

11–2 Data Encoding
Publication 1770Ć6.5.16 - October 1996
In general, PLC processors store binary data (1s and 0s) in 16-bit
groups called words. If you are looking at this data from a
computer, however, you may interpret it in a number of different
ways, depending on your application needs. You may use any one of
the following numbering systems to represent data in your computer
application programs:
Numbering System Page
decimal 11-2
binary 11-3
binary coded decimal 11-3
hexadecimal 11-4
octal 11-5
binary floating point 11-5
Important: You must design your computer application programs to
make any necessary conversions from one numbering
system to another. Once you have selected the
numbering system that is best for your applications,
use that numbering system and convert all data values
to that base.
Decimal
The decimal numbering system is easy to use because it is most
familiar. It uses the digits 0 through 9, and each digit has a place
value that is a power of 10. Despite the convenience of decimal
numbers, it is often easier to convert binary data to a numbering
system other than decimal.
Decimal Representation, Number 239
2 x 10
2
= 200
3 x 10
1
= 30
9 x 10
0
= 9
2 3 9
239
10
10
Numbering Systems