Vega VEGADIF 65 Operating Instructions Manual page 13

Power supply and bus
communication
VEGADIF 65 • Foundation Fieldbus
For connection to the processe, the marking "+" and "-" on the process
component in chapter "Mounting and connection instructions" must
hence be noted. The pressure effective on "+" goes positive, the
effective pressure on "-" goes negative into the calculation of the
pressure difference.
The configuration of the measuring cells differs depending on the
measuring range:
p
Fig. 7: Metallic measuring cell 10 mbar and 30 mbar - p
pressures
1
Measuring element
2
Silicone diaphragm
3
Separating diaphragm
4
Filling oil
5
Integrated overvoltage arrester
1
p
1
Fig. 8: Metallic measuring cell from 100 mbar - p
1
Measuring element
2
Overload diaphragm/Middle diaphragm
3
Filling oil
4
Separating diaphragm
Power is supplied via the H1 Fieldbus. A two-wire cable according to
Fieldbus specification serves as carrier of both power and digital data
for multiple sensors. This cable can be operated in two versions:
via an H1 interface card in the control system and additional power
l
supply
1
3 Product description
1
2
3
p
4
2
5
and p process
1 2
2
3
p
2
4
and p process pressures
1 2
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