Signedćmagnitude binary – Rockwell Automation 1771-OFE/B Analog Output Module User Manual User Manual
Page 76
C-2
Publication 1771Ć6.5.30 - November 1998
Table C.A
BCD Representation
Place Value
2
3
(8)
2
2
(4)
2
1
(2)
2
0
(1)
Decimal
Equivalent
0
0
0
0
0
0
0
0
1
1
0
0
1
0
2
0
0
1
1
3
0
1
0
0
4
0
1
0
1
5
0
1
1
0
6
0
1
1
1
7
1
0
0
0
8
1
0
0
1
9
Signed-magnitude binary is a means of communicating numbers to
your processsor. It should be used with the PLC-2 family when
performing computations in the processor. It cannot be used to
manipulate binary 12-bit values or negative values.
Example: The following binary number is equal to decimal 22.
10110
2
= 22
10
The signed-magnitude method places an extra bit (sign bit) in the
left-most position and lets this bit determine whether the number is
positive or negative. The number is positive if the sign bit is 0 and
negative if the sign bit is 1. Using the signed magnitude method:
0 10110 = +22
1 10110 = -22
SignedĆmagnitude Binary