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6 installation example for vbus-sensors, 7 screening of the vbus-line, 6 installation example for vbus- sensors – VEGA VEGALOG 571 User Manual

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34

VEGALOG 571

Electrical connection

3.6 Installation example for VBUS-

sensors

Example 1

One common (two-wire) bus line for five
sensors each is looped from the control room
up to the last sensor of the group.

Example 2

One common (two-wire) bus line for five
sensors each is looped from the control room
to the plant and from there, star-shaped, to
the sensors. The star point should be as
close as possible to the sensors.

Example 3

Each sensor gets an own line pair (not rec-
ommended).

VEGALOG 571
with EV-card

VEGALOG 571
with EV-card

VEGALOG 571
with EV-card

Line length up to 1000 m

Line length up to 1000 m

Line length max. 100 m per sensor

3.7 Screening of the VBUS-line

The use of screened lines is recommended
for all VBUS-circles. The earthing of the
screen should be on one end, close to the
processing system. Each EV-card uses an
own VBUS-loop.

If only a single VBUS-loop is operated in an
interference-free environment, an un-
screened line can be used.

For systems consisting of several VBUS-
circles, the circles must not be screened
together.

VEGALOG 571
with 2 EV-cards

VBUS 1

VBUS 2