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C - data table formats, Digit binary coded decimal, Data table formats – Rockwell Automation 1771-IR , D17716.5.76 RTD INPUT MODULE User Manual

Page 52

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Appendix

CĆ1

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

1

1

1

1

0

0

1

1

2

3

9

10

1 2

3

9

12955-I

4-Digit Binary Coded Decimal

(BCD)