User Manual

VEGAPULS 42 and 44 – 4 … 20 mA 19
Types and versions
2
-
+
4 … 20mA
2
2
2
1)
4
Measuring system with VEGAPULS 42 or 44 in four-wire technology
• Four-wire technology, supply and output signal via two separate two-wire cables.
• Output signal 4 … 20 mA active.
• Optional external indicating instrument with analogue and digital display (can be mounted
up to 25 m separated from the sensor).
• Adjustment with PC, HART
®
handheld or adjustment module MINICOM (can be plugged into
the sensor or into the external indicating instrument VEGADIS 50).
• Max. resistance on the signal output (load) 500 W.
(active)
2)
VEGADIS 50
1)
If the resistance of the processing systems
connected to the 4 … 20 mA signal output is less
than 250 W, a resistor must be connected to the
connection cable during adjustment to get a loop
resistance of 250 W.
The digital adjustment signal would otherwise be
severely damped or short-circuited due to
insufficient resistance of the connected
processing system. Communication with the PC
would not be ensured.
HART
®
handheld
VEGA-
CONNECT 2
³ 250 W
2)
4 … 20 mA active means that the sensor delivers
a level-dependent current of 4 … 20 mA (source).
The sensor reacts electrically to the processing
system (e.g. display) like a current source.