User Manual

VEGAPULS 42 and 44 – 4 … 20 mA 23
Types and versions
VEGAPULS 42 Ex or 44 Ex (loop powered) with pressure-tight encapsulated
terminal compartment on active PLC
• Two-wire technology, supply via the signal cable of active PLC on Exd connection housing
for operation in Ex zone 1 (VEGAPULS …Ex) or Ex zone 0 (VEGAPULS …Ex0).
• Output signal 4 … 20 mA (passive).
• Measured value display integrated in the sensor.
• Optional external indicating instrument (can be mounted up to 25 m separated from the
sensor in Ex area).
• Adjustment with PC, HART
®
handheld or 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 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 or
the HART
®
handheld would not be ensured.
2
4 … 20 mA
2
2
4
2
VEGA-
CONNECT 2
VEGADIS 50 Ex
passive
2)
Ex area
Non Ex-area
HART
®
hand-
held
PLC (active)
2)
4 … 20 mA passive means that the sensor
consumes a level-dependent current of
4 … 20 mA. The sensor reacts electrically like a
varying resistor (consumer) to the PLC.