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l
Byte-No.
1
2
IEEE-754-
Format
Floating point value
PA-OUT
Value
(FB1)
Data format of the output signal
Byte2 Byte1 Byte0
Byte4 Byte3
Status
Value (IEEE-754)
Fig. 34: Data format of the output signal
The status byte corresponds to profile 3.0 "Profibus PA Profile for Process Control Devices" coded.
The status "Measured value OK" is coded as 80 (hex) (Bit7 = 1, Bit6 ... 0 = 0).
The measured value is transferred as a 32 bit floating point number in the IEEE-754 format.
Byte n
Bit
Bit
Bit
Bit
Bit
Bit
Bit
4
7
6
5
3
2
1
7
6
5
4
3
VZ
2
2
2
2
2
2
Sign
Exponent
Bit
(Exponent - 127)
VZ
2
Value = (-1)
Fig. 35: Data format of the measured value
Coding of the status byte associated with the PA output value
Status
Description according to Pro-
code
fibus standard
0x00
bad - non-specific
0x04
bad - configuration error
VEGAFLEX 61 • Profibus PA
3
4
5
Status
Status
(FB1)
Byte n+1
Bit
Bit
Bit
Bit
Bit
Bit
Bit
0
4
7
6
5
3
2
0
-2
-3
-4
2
2
1
2
2
-1
2
2
2
2
Significant
(1 + Significant)
Possible cause
Flash-Update active
l Adjustment error
l Configuration error with PV-Scale (PV-Span too small)
l Unit irregularity
l Error in the linearization table
Byte n+2
Bit
Bit
Bit
Bit
Bit
Bit
Bit
4
7
6
5
3
1
0
-9
-10 -11 -12 -13 -14 -15 -16 -17
2
2
2
2
2
-6
-7
-8
-5
2
2
Significant
10 Supplement
Byte n+3
Bit
Bit
Bit
Bit
Bit
Bit
Bit
0
2
1
7
6
5
4
-18 -19 -20 -21 -22 -23
2
2
2
2
2
2
2
Significant
Bit
Bit
Bit
Bit
3
2
1
0
2
2
2
2
57
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