C - data table formats, Digit binary coded decimal (bcd), Data table formats – Rockwell Automation 1771-IL/B , D17716.5.91 ISOLATED ANALOG INPUT Module User Manual
Page 55: Appendix
Appendix
C
C-1
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
4-Digit 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
4-Digit Binary Coded
Decimal (BCD)