separate power supply
(
sensors in four
-
wire version
).
T
he
connection and operation in
E
x ia is not permitted on the
passive input
.
N
ote
:
VEGASCAN
693
is designed for connection of up to
15
HART
sensors
(
5
with
E
x
).
B
ecause they are accessed via di
ff
erent
addresses in the
HART
multidrop mode
,
all sensors must be
connected to the same sensor input
.
T
hese are either
terminals
1
/
2
(
active input
)
or terminals
3
/
4
(
passive input
).
M
ixed operation of active and passive input is not possible
.
S
ince this is a digital bus system
,
only one two
-
wire cable
should lead to the sensors
.
A
distributor can then be
connected directly forward of the sensors
.
A
s an alternative
,
the connection cable can be looped through the second cable
entry on the sensor housing
.
5
.
3
W
iring plans
17 18 19 20 21 22
9
10
11 12
1
2
3
4
23 24 25 26 27 28
13 14
15 16
5
6
7
8
L1 N
+ -
+ -
+ -
5
3
1
4
2
6
7
8
F
ig
.
3
:
C
onnection example
VEGASCAN
693
with two
-
wire sensors
1
M
easured data input with sensor supply
(
active input
)
2
M
easured data input
(
passive input
),
not in
E
x ia
3
I
nternal fail safe relay
4
D
istributor
5
P
ower supply of
VEGASCAN
693
6
HART
two
-
wire sensor with
M
ultidrop address
1
7
HART
two
-
wire sensor with
M
ultidrop address
2
8
HART
two
-
wire sensor with
M
ultidrop address
3
W
iring plan for two
-
wire sen
-
sors
14
VEGASCAN
693
-
15
-
channel
HART
signal conditioning instrument
E
lectrical connection
29252
-
EN
-
060513