wtw MIQ/2-PR, Operating Manual, Page: 21 / 28

MIQ/2-PR Interface for the PROFIBUS
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3.6.5 Data formats
Measured values The data for the main and secondary measured values are transmitted
in the IEE-754 standard 32-bit floating point format.
* MSB = Most significant bit, LSB = Least significant bit
If not all of the bits of the exponent are 0, the value is calculated accord
-
ing to:
If all of the bits of the exponent are 0, the value is calculated according
to:
A value is 0 if all the bits of both the exponent and the mantissa are 0.
Sensor model
Status info
The data for the sensor model and status info is transmitted as INT16,
i.e. consists of 2 bytes. The assignment is carried out in Motorola for
-
mat (the higher value byte first).
Measured value status The data for measured value status of the main and secondary mea
-
sured values are encoded jointly into a single byte. Bits 7-4 encode the
status of the main measured value, bits 3-0 encode the status of the
secondary measured value.
Other data All other data always consist of only a single byte (Int8).
Address Bit representation
Offset 0h bits 31-24 S = sign (bit 31)
E = exponent
(bits 30-23)
M = mantissa (bits 22-0)
Offset 1h bits 23-16
Offset 2h bits 15-8
Offset 3h bits 7-0
If the measured value is equal to 0, check the measured
value status. If the measured value status is not equal to 1,
an error has occurred and the measured value is invalid.
MSB* LSB*
S E E E E E E E
E M M M M M M M
M M M M M M M M
M M M M M M M M
) 2 ... 2 2 2 1 ( 2 1
23
0
3
20
2
21
1
22
127
− − − − −
⋅ + + ⋅ + ⋅ + ⋅ + ⋅ ⋅ − =
b b b b
E S
M M M M V
) 2 ... 2 2 2 ( 2 1
23
0
3
20
2
21
1
22
126
− − − − −
⋅ + + ⋅ + ⋅ + ⋅ ⋅ ⋅ − =
b b b b
S
M M M M V
Address Bit representation Information
Offset 0h bits 15-8 High byte
Offset 1h bits 7-0 Low byte
MSB LSB