VEGA VEGAPULS 56K - Manual (Page 29)

VEGAPULS 56K 29
22915-EN-041227
2
4
4 ... 20 mA
2
2
2
Electrical connection
Measuring system with VEGAPULS 56K Ex, 56K Ex0 via a safety barrier in
Ex area on active PLC
• Two-wire technology (loop powered), power supply via the signal line of the PLC; output
signal 4 … 20 mA (passive).
• Separator transfers the non intrinsically safe PLC circuit to the intrinsically safe circuit, so
that the sensor can be used in Ex zone 1 (VEGAPULS 56K Ex) or in zone 0 (VEGAPULS
56K Ex0)
• max. resistance of the signal cable 15
Ω per wire
• 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 adjustment module MINICOM (can be plugged into
the sensor or into the external indicating instrument VEGADIS 50).
HART ® handheld
Ex area Non Ex area
Safety barrier
(see „3.3 Approvals“)
VEGA-
CONNECT 2
VEGADIS 50 Ex
passive
1 )
PLC
EEx ia
1) 4 … 20 mA passive means that
the sensor or the PLC consumes a
level-dependent current of
4 … 20 mA. The PLC reacts
electrically like a varying resistor
(consumer) to the PLC.