Operating Instructions - VEGAPULS 54K enamel

3.4 Configuration of measuring systems
A measuring system consists of a sensor
with 4 … 20 mA signal output and a unit that
evaluates and further processes the levelproportional
current signal.
On the following pages, you will see a
number of instrument configurations, designated
as "measuring systems“, some of
which are shown with signal processing
units.
4
2
4 … 20 mA
1)
> 250 Ω
Measuring systems in two-wire technology:
4 … 20 mA shown without processing unit
4 … 20 mA on active PLC
4 … 20 mA on active PLC (Ex area),
4 … 20 mA on passive PLC
4 … 20 mA on indicating instrument
VEGADIS 371 Ex
Measuring systems in four-wire technology:
4 … 20 mA shown without signal conditioning
instrument
Measuring systems with VEGAPULS 54K on any voltage source
VEGADIS 50
VEGA-
CONNECT 2
20 VEGAPULS 54K enamel
+
-
HART ® handheld
Electrical connection
Two-wire technology (loop powered), supply and output signal via one two-wire cable.
Output signal 4 … 20 mA (passive).
Optional external indicating instrument with analogue and digital display (can be mounted
up to 25 m away from the sensor).
Adjustment with PC, HART ® handheld or the adjustment module MINICOM (can be plugged
into the sensor or into the external indicating instrument VEGADIS 50).
1) If the resistance of the processing systems
connected to the 4 … 20 mA signal output is less
than 200 Ω, a resistor must be connected to the
connection cable during adjustment to get a loop
resistance of 250 Ω up to 350 Ω.
The digital adjustment signal would otherwise be
severely damped or short-circuited due to
insufficient resistance of the connected processing
system. Digital communication with the PC
would not be ensured.
24 101-EN-041227