Omron SYSMAC CV Series User Manual

106
When the sign bit is ON, on the other hand, the number will be negative, and the
method for converting to decimal will be different. Because the value is ex-
pressed in 2’s complement, it must first be converted to a negative number and
then the value of each digit can be multiplied by its respective factor. For exam-
ple,the hexadecimal value “CFC7” would be converted as follows:
1100
C
1111
F
1100
C
0111
7
1100
C
1111
F
1100
C
0110
6
0011
3
0000
0
0011
3
1001
9
2’s complement
True value (negative)
Subtract 1.
Reverse the status of each bit.
The negative decimal number is then calculated as follows:
–[(3 x 16
3
) + (0 x 16
2
) + (3 x 16
1
) + (9 x 16
0
)] = –12,345
Note To convert a negative decimal number into signed binary data, follow the above
procedure in reverse. In other words, first convert the absolute value into 2’s
complement, then reverse the bits and add one.
The hexadecimal range is 0000 to 7FFF for a positive number and 8000 to FFFF
for a negative number. These are equivalent in decimal to 0 to +32,767 for a posi-
tive number and -32,768 to -1 for a negative number.
Two-word data is handled as 32 bits of binary data, with the leftmost bit of the
leftmost word used as the sign bit. Values can be expressed as eight-digit hexa-
decimal (0000 0000 to 7FFF FFFF, 8000 0000 to FFFF FFFF), and the equiva-
lent decimal range is 0 to +2,147,483,647 (positive) and –1 to –2,147,483,648
(negative).
Unsigned binary data Decimal number Signed binary data
FFFF +65,535
FFFE +65,534
etc.
etc.
Cannot be expressed.
8001 +32,769
8000 +32,768
7FFF +32,767 7FFF
7FFE +32,766 7FFE
etc. etc. etc.
0002 +2 0002
0001 +1 0001
0000 0 0000
-1 FFFF
-2 FFFE
Cannot be expressed.
etc. etc.
-32,767 8001
-32,768 8000
Range of Expression
Double Data
Correlation Between Binary
Data and Decimal Numbers
Data Formats Section 4-13

Omron SYSMAC CV Series Specifications

General

Brand	Omron
Model	SYSMAC CV Series
Category	Controller
Language	English