Vega VEGAPULS 63 Operating Instructions Manual page 74

11 Supplement
Ʋ Bus specifications
Ʋ Data protocols
Max. transmission rate
Accuracy (according to DIN EN 60770-1)
Process reference conditions according to DIN EN 61298-1
Ʋ Temperature
Ʋ Relative humidity
Ʋ Air pressure
Installation reference conditions
Ʋ Min. distance to internal installations
Ʋ Reflector
Ʋ False reflections
Deviation with liquids
10 mm (0.394 in)
2 mm (0.079 in)
0
- 2 mm (- 0.079 in)
- 10 mm (- 0.394 in)
1 2
Fig. 48: Deviation under reference conditions
1 Reference plane
2 Antenna edge
3 Recommended measuring range
Repeatability
Variables influencing measurement accuracy
Temperature drift - Digital output
Additional deviation through electromag-
netic interference acc. to EN 61326
Influence of the superimposed gas and pressure on measurement accuracy
The propagation speed of the radar impulses in gas or vapour above the medium is reduced by
high pressure. This effect depends on the type of superimposed gas or vapour and is especially
large at low temperatures.
The following table shows the resulting deviation for some typical gases and vapours. The specified
values refer to the distance. Positive values mean that the measured distance is too large, negative
values that the measured distance is too small.
74
Modbus Application Protocol V1.1b3, Modbus over se-
rial line V1.02
Modbus RTU, Modbus ASCII, Levelmaster
57.6 Kbit/s
+18 ... +30 °C (+64 ... +86 °F)
45 ... 75 %
860 ... 1060 mbar/86 ... 106 kPa (12.5 ... 15.4 psig)
> 200 mm (7.874 in)
Flat plate reflector
Biggest false signal, 20 dB smaller than the useful signal
See following diagrams
0,5 m (1.6 ft)
≤ ±1 mm
±3 mm/10 K, max. 10 mm
< ±50 mm
VEGAPULS 63 • Modbus and Levelmaster protocol
3