VEGA VEGAPULS 68 (≥ 2.0.0 - ≤ 3.8) Foundation Fieldbus - Manual (Page 55)

Output variable
Output
-
Signal digital output signal, Foundation Fieldbus protocol
-
Physical layer according to IEC 61158-2
Channel Numbers
-
Channel 1 Primary value
-
Channel 2 Secondary value 1
-
Channel 3 Secondary value 2
Transmission rate 31.25 Kbit/s
Current value 10 mA, ±0.5 mA
Damping (63 % of the input variable) 0 … 999 s, adjustable
Input variable
Measured value distance between process fitting and product sur-
face
Max. measuring range 70 m (229.7 ft)
Min. distance from antenna end 400 mm (15.75 in)
Reference conditions to measuring accuracy (similar to DIN EN 60770-1)
Reference conditions according to DIN EN 61298-1
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Temperature +18 … +30 °C (+64 … +86 °F)
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Relative humidity 45 … 75 %
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Air pressure 860 … 1060 mbar/86 … 106 kPa (12.5 … 15.4 psig)
Other reference conditions
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Reflector ideal reflector, e.g. metal plate 2 x 2 m
-
False reflections Biggest false echo, 20 dB smaller than the useful
echo
Characteristics and performance data
Frequency K-band
Interval approx. 1 s
Beam angle -3 dB with horn antenna, depending on antenna diameter
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ø 40 mm (1.575 in) 22°
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ø 48 mm (1.89 in) 18°
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ø 75 mm (2.953 in) 10°
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ø 95 mm (3.74 in) 8°
Beam angle -3 dB with parabolic antenna 4°
Step response or adjustment time 5) > 1 s (dependent on the parameter setting)
5) Time to output the correct level (with max. 10 % deviation) after a sudden
level change.
VEGAPULS 68 • Foundation Fieldbus 55
10 Supplement
29264
-EN
-090305