C - data table formats, Data table formats, Appendix – Rockwell Automation 1771-IFF/A,D17716.5.116 FAST ANALOG INPUT MODULE User Manual
Page 77: 4ćdigit binary coded decimal (bcd)
Appendix
C
Publication 1771Ć6.5.116 - July 1996
Data Table Formats
The 4-digit BCD format uses an arrangement of 16 binary digits to
represent a 4-digit decimal number from 0000 to 9999 (Figure C.1).
The BCD format is used when the input values are to be displayed
for operator viewing. Each group of four binary digits is used to
represent a number from 0 to 9. The place values for each group of
digits are 2
0
, 2
1
, 2
2
and 2
3
(Table C.A). The decimal equivalent for a
group of four binary digits is determined by multiplying the binary
digit by its corresponding place value and adding these numbers.
Figure C.1
4ĆDigit Binary Coded Decimal
0 X 2
3
= 0
0 X 2
2
= 0
0 X 2
1
= 0
1 X 2
0
= 1
0 X 2
3
= 0
0 X 2
2
= 0
1 X 2
1
= 2
0 X 2
0
= 0
0 X 2
3
= 0
0 X 2
2
= 0
1 X 2
1
= 2
1 X 2
0
= 1
1 X 2
3
= 8
0 X 2
2
= 0
0 X 2
1
= 0
1 X 2
0
= 1
0
0
0
1
0
0
1
0
0
0
1
1
1
0
0
1
1
2
3
9
10
1
2
3
9
12955-I
4ĆDigit Binary Coded
Decimal (BCD)