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Instruction Manual
4.1.1.1
Input Data (from device to master)
Input data are user data (measured values) which are transmitted from the device to the master in the
following format:
Every measured value consists of 5 bytes which are composed of a floating point value corresponding with
IEEE -- 754 (4 bytes) and the appropriate measured value status (1 byte). First the measured value and
then the corresponding status is transmitted in the PROFIBUS telegram.
Byte
No.
7 (MSB)
1
VZ
2
E
0
2
3
M
- -8
2
4
M
- -16
2
VZ: sign;
0 = positive, 1 = negative
Table 4--1
Measured value format
Byte
No.
7 (MSB)
5
Quality
Table 4--2
Status byte format
The status bytes consist of 3 components:
Quality
D
Substatus
D
Limits
D
The components can use the following values with SITRANS F:
Bit
Profile description
7
6
0
0
bad
0
1
uncertain
1
0
good (not cascade)
Table 4--3
Quality
12
6
5
E
E
7
6
2
2
M
M
- -1
- -2
2
2
M
M
- -9
- -10
2
2
M
M
- -17
- -18
2
2
6
5
(the maximum value bits 6 and 7):
(bit 2 to 5):
(the minimum bits 0 and 1):
Meaning
Measured value cannot be used
Measured value uncertain
Measured value o.k.
Bit
4
3
E
E
5
4
2
2
M
M
- -3
- -4
2
2
M
M
- -11
- -12
2
2
M
M
- -19
- -20
2
2
E: Exponent
Bit
4
3
Substatus
describes the basic quality of the
corresponding measured value
differentiates the quality of the
corresponding measured value
signal that limit values have been
exceeded
2
1
E
E
3
2
2
2
M
M
- -5
- -6
2
2
M
M
- -13
- -14
2
2
M
M
- -21
- -22
2
2
M: Mantissa
2
1
Limits
SITRANS F with PROFIBUS PA
C79000-B5676-C114-03
0 (LSB)
E
1
2
M
- -7
2
M
- -15
2
M
- -23
2
0 (LSB)
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