VEGA VEGADIF 34 … 51 - Manual (Page 38)

38 VEGADIF 34 … 51
20094-EN-030731
250
Ω
Ri < 250
Ω
+
-
Ri > 250
Ω
+
-
Electronics powered by PLC with active input circuit
Set-up
PLC
PLC
4.3 Adjustment with the HART ® handheld
Apart from adjustment with the 4-key adjustment element in the sensor and adjustment with the
PC and the adjustment software VVO, a VEGADIF can be also operated with a HART
® handheld.
If the inner resistance of the power supply is less than 250
Ω
, a resistor of
R
X
= 250
Ω
1 /
4
W must be connected to the signal /connection cable during adjustment.
The digital adjustment and communication signals would otherwise be short-circuited because
of insufficient resistances of the supply current source or the processing system - sensor com-
munication would not be ensured.