Specifications

e Electro Industries/GaugeTech Doc # E145701 B-2
B.4: Floating Point Values
Q
Floating Point Values are represented in the following format:
Register
Byte
Bit
Meaning
7
s
01
0
sign
01
1
56 43210
eeeeeee
exponent
67
em
54
mm
3
m
21
mmm
07
m
6
m
5
m
4
m
3
mm
2
m
10
m
157
mmmmmmmm
64320
mantissa
Q
The formula to interpret a Floating Point Value is: -1
sign
x 2
exponent-127
x1.mantissa = 0x0C4E11DB9
Register
Byte
Bit
1
Meaning s
sign
1
7 6543210765432107654321076543210
100 100 0111000010001110110111001
eeeeeeeemmmmmmmmmmmmmmmmmmmmmmm
0x0C4 0x0E1 0x01D 0x0B9
exponent mantissa
0x089 = 137 0b011000010001110110111001
0x0C4E1 0x01DB9
Q
Formula Explanation
C4E11DB9 (hex) 11000100 11100001 00011101 10111001 (binary)
The sign of the mantissa (and therefore the number) is 1, which represents a negative value.
The Exponent is 10001001 (binary) or 137 decimal.
The Exponent is a value in excess 127. So, the Exponent value is 10.
The Mantissa is 11000010001110110111001 binary.
With the implied leading 1, the Mantissa is (1).C23B72 (hex).
The Floating Point Representation is therefore -1.75871956 times 2 to the 10.
Decimal equivalent: -1800.929
NOTE: Exponent = the whole number before the decimal point.
Mantissa = the positive fraction after the decimal point.
B.5: Modbus Register Map (MM-11 to MM-88)
Q
The Shark 100 Modbus Register Map begins on the following page.
137 127
10
1 2 1 11000010001110110111001
1 2 1.75871956
1800.929
sign
xx
xx
−
−
−
−
i