VEGA VEGAPULS 61 (≥ 2.0.0 - ≥ 4.0.0) Profibus PA Approval according to LPR radio standard - Manual (Page 77)

Byte-No. 1 2 3 4 5
Format IEEE-754-Floating point value Status
Value AI FB 1 (OUT) AI FB 1
Note:
Bytes 6-15 are not used in this example.
Data format of the output signal
Byte4 Byte3 Byte2 Byte1 Byte0
Status Value (IEEE-754)
Fig. 53: Data format of the output signal
The status byte corresponds to profile 3.02 "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 Byte n+1
Bit
7
VZ
Exponent
Bit
6
2
Bit
5
2
Bit
4
2
Bit
3
2
Bit
2
2
Bit
1
2
Bit
0
2
Bit
7
2
Bit
6
2
Bit
5
2
Bit
4
2
Bit
3
2
Bit
2
2
Bit
1
2
Bit
0
2
Sign
Bit
Significant
7 6 5 4 3 2 1 0 -1 -2 -3 -4 -5 -6 -7
Byte n+2 Byte n+3
Bit
7
2
Significant
Bit
6
2
Bit
5
2
Bit
4
2
Bit
3
2
Bit
2
2
Bit
1
2
Bit
0
2
Bit
7
2
Bit
6
2
Bit
5
2
Bit
4
2
Bit
3
2
Bit
2
2
Bit
1
2
Bit
0
2
Significant
-9 -10 -11 -12 -13 -14 -15 -16 -17 -18 -19 -20 -21 -22 -23 -8
Value = (-1) VZ 2 (Exponent - 127) (1 + Significant)
Fig. 54: Data format of the measured value
Coding of the status byte associated with the PA output value
You can find further information for the coding of the status byte in the Device Description 3.02 on
www.profibus.com.
VEGAPULS 61 • Approval according to LPR radio standard 77
11 Supplement
41715
-
EN
-120301