JUMO mTRON T Manual page 39

NOTE!
The order of the bytes depends on how the float values are saved in the respective applica-
tion. The bytes may have to be changed over in the interface program accordingly.
3.7.3 Double values
For double values, Modbus also operated with the IEE 754 standard format (32 bit). Unlike float
values, bytes are not changed over for double values.
Double-float format (32 bit) acc. to IEEE 754 standard
SEEEEEEE
Byte 1
MMMMMMMM
Byte 5
S - sign bit
E - exponent (two's complement)
M - 52 bits normalized mantissa
Modbus double format
SEEEEEEE
Byte 1
MMMMMMMM
Byte 5
EEEEMMMM
Byte 2
MMMMMMMM
Byte 6
Modbus address x
EEEEMMMM
Byte 2
Modbus address x+2
MMMMMMMM
Byte 6
3 Modbus protocol description
MMMMMMMM
Byte 3
MMMMMMMM
Byte 7
Modbus address x+1
MMMMMMMM
Byte 3
Modbus address x+3
MMMMMMMM
Byte 7
MMMMMMMM
Byte 4
MMMMMMMM
Byte 8
MMMMMMMM
Byte 4
MMMMMMMM
Byte 8
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