8 approvals, 9 data format of the output signal – VEGA VEGAFLEX 52P (Profibus PA) User Manual
Page 17
VEGAFLEX 51P and 52P
17
Product description
1.8 Approvals
VEGAFLEX sensors are approved for StEx Zone 10.
Please note the attached approval documents if you want to use a sensor in Ex environment.
1.9 Data format of the output signal
Byte4
Byte3
Byte2
Byte1
Byte0
Status
Meas. value (IEEE-754 format, see below)
Status byte:
The status byte corresponds to the profile 3.0 "Profibus PA Profile for Process Control De-
vices" coded. The status "Meas. value OK" is coded as 80 (hex) (Bit7 = 1, Bit 6 … 0 = 0).
Measured value:
The meas. value is transferred as 32 Bit floating point number in the IEEE-754 format.
Byte n
Byte n+1
Bit
Bit
Bit
Bit
Bit
Bit
Bit
Bit
Bit
Bit
Bit
Bit
Bit
Bit
Bit
Bit
7
6
5
4
3
2
1
0
7
6
5
4
3
2
1
0
VZ
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
2
-1
2
-2
2
-3
2
-4
2
-5
2
-6
2
-7
Sign
Exponent
Mantissa
Byte n+2
Byte n+3
Bit
Bit
Bit
Bit
Bit
Bit
Bit
Bit
Bit
Bit
Bit
Bit
Bit
Bit
Bit
Bit
7
6
5
4
3
2
1
0
7
6
5
4
3
2
1
0
2
-8
2
-9
2
-10
2
-11
2
-12
2
-13
2
-14
2
-15
2
-16
2
-17
2
-18
2
-19
2
-20
2
-21
2
-22
2
-23
Mantissa
Mantissa
Formula:
Meas. value = (-1)
VZ
• 2
(Exponent - 127)
• (1 + Mantissa)
Examples:
41 70 00 00 (hex) = 0100 0001 0111 0000 0000 0000 0000 0000 (bin)
Meas. value
= (-1)
0
• 2
(130 - 127)
• (1 + 2
-1
+ 2
-2
+ 2
-3
)
= 1 • 2
3
• (1 + 0.5 + 0.25 + 0.125)
= 1 • 8 • 1.875
= 15.0