ProgrammingAppendix A

Note Signed BCD Data

Signed BCD data is a special data format that is used to express negative numbers in BCD. Although this format is found in applications, it is not strictly defined and depends on the specific application. The FQM1 supports four data formats and supports the following instructions to convert the data formats: SIGNED BCD-TO-BINARY: BINS(470) and SIGNED BINARY-TO-BCD: BCDS(471). Refer to the Instructions Reference Manual (Cat. No. O011) for more information.

Decimal

Hexadecimal

Binary

 

BCD

 

 

 

 

 

 

0

0

0000

0000

 

 

 

 

 

 

 

 

1

1

0001

0001

 

 

 

 

 

 

 

 

2

2

0010

0010

 

 

 

 

 

 

 

 

3

3

0011

0011

 

 

 

 

 

 

 

 

4

4

0100

0100

 

 

 

 

 

 

 

 

5

5

0101

0101

 

 

 

 

 

 

 

 

6

6

0110

0110

 

 

 

 

 

 

 

 

7

7

0111

0111

 

 

 

 

 

 

 

 

8

8

1000

1000

 

 

 

 

 

 

 

 

9

9

1001

1001

 

 

 

 

 

 

 

10

A

1010

0001

 

0000

 

 

 

 

 

 

11

B

1011

0001

 

0001

 

 

 

 

 

 

12

C

1100

0001

 

0010

 

 

 

 

 

 

13

D

1101

0001

 

0011

 

 

 

 

 

 

14

E

1110

0001

 

0100

 

 

 

 

 

 

15

F

1111

0001

 

0101

 

 

 

 

 

 

16

10

10000

0001

 

0110

 

 

 

 

 

 

Decimal

Unsigned binary (4-digit hexadecimal)

Signed binary (4-digit hexadecimal)

 

 

 

+65,535

FFFF

Cannot be expressed.

 

 

 

+65,534

FFFE

 

 

 

 

.

.

 

.

.

 

.

.

 

 

 

 

+32,769

8001

 

 

 

 

+32,768

8000

 

 

 

 

+32,767

7FFF

7FFF

 

 

 

+32,766

7FFE

7FFE

 

 

 

.

.

.

.

.

.

.

.

.

 

 

 

+2

0002

0002

 

 

 

+1

0001

0001

 

 

 

0

0000

0000

 

 

 

–1

Cannot be expressed.

FFFF

 

 

 

–2

 

FFFE

 

 

 

.

 

.

.

 

.

.

 

.

 

 

 

–32,767

 

8001

 

 

 

–32,768

 

8000

 

 

 

278

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Omron FQM1-MMA21, FQM1-CM001, FQM1-MMP21 operation manual Decimal Hexadecimal Binary, Ffff, Fffe, 7FFF, 7FFE