VEGA VEGALOG 571 - Manual (Page 34)

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