Dynamic Fluid Measurement
DATA PACKET
ENRON MODBUS SPECIFICATIONS
16 BITS INTEGER
The short word numeric variable is a 16-bit integer. A short word is transmitted as two 8-bit bytes, 4
characters.
Example:
BBA (HEX) = 3002 (Decimal)
32 BITS INTEGER
The long word numeric variable is a two 16-bit integers. A long word is transmitted as four 8-bit bytes, 8
characters.
Example:
38270 (HEX) = 230000 (Decimal)
Floating Point
32-bit single precision floating-point numbers are read as groups of four bytes (8 characters) with the
following specific bit order
Sign
Exponent
(1 bit)
(8 bits)
SEEEEEEE
EMMMMMMM
Byte 3
Byte 2
S: is the sign bit.
E: is the two's exponent.
M: is 23 bit normalized mantissa.
E-CHART Manual
Mantissa
(23 bits)
MMMMMMMM
MMMMMMMM
Byte 1
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Modbus Data – 4-45
Byte 0