Technical data

Normalized fixed point
numbers
One word is required to represent a normalized fixed point number in
a data block. The following example illustrates the difference between
a fraction represented decimally, in binary and using the KF format on
the programmer.
Fraction in Fixed point
number
Decimal
representation
Binary representation
-0.999... .
-0.75
-0.5
-0.25
0
+0.25
+0.5
+0.75
+0.999... .
1000000000000001
1010000000000000
1100000000000000
1110000000000000
0000000000000000
0010000000000000
0100000000000000
0110000000000000
0111111111111111
-32767
-24576
-16384
-8192
0
+ 8192
+16384
+24576
+32767
Negative normalized fixed point numbers in a binary representation
are obtained by forming the 2’s complement of the positive
normalized fixed point number.
Normalized fixed point numbers (NF) can be converted to the values
represented in the programmer (KF) as follows:
NF * 32767 = KF
where -1 < NF <+1 and -32767
≤ KF ≤ +32767
Table 6-12 Fraction
OB 250/251: Closed-Loop Control/ PID Algorithm
CPU 928B Programming Guide
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