VEGA VEGASON 51K…53K - Manual (Page 12)

12 VEGASON 51K … 53K
2
4 … 20 mA
2
2
2
4
Types and versions
Measuring system with VEGASON 51K … 53K via separator in Ex-area on
active DCS
• Two-wire technology (loop powered), supply via the signal line on the DCS; output signal
4 … 20 mA (passive)
• Separator converts the not-intrinsically safe DCS-circuit into an intrinsically safe circuit, the
sensor can therefore also be used in Ex-zone 1
• Optional external indicating instrument with analogue and digital indication (can be mounted
up to 25 m away from the sensor)
• Adjustment with PC, HART ® -handheld or adjustment module MINICOM (can be plugged in
the sensor or in the external indicating instrument VEGADIS 50)
HART ® -handheld
Ex-area Not Ex-area
Separator (e.g. Stahl)
(see "3.2 Approvals“)
VEGA-
CONNECT 2
VEGADIS 50
passive 2)
1 )
DCS active
1) If the resistors of the processing systems
connected to the 4 … 20 mA-signal output are less
than 200
Ω
, a resistor of 250
Ω
to 350
Ω
must be
connected to the connection line during adjust-
ment.
The digital adjustment signal would be extremely
damped or short-circuited via too small input
resistors of the connected processing system
which means that the digital communication with
the PC could no longer be ensured.
2) 4 … 20 mA passive means that the sensor takes a
current of 4 … 20 mA depending on the level. The
sensor, therefore, reacts electrically like a resistor
(consumer) on the DCS. The DCS operates
actively, i.e. as current or voltage supply.