Masoneilan SVI3 Installation and Maintenance Manual
=
| 115
© 2021 Baker Hughes Company. All rights reserved.
7.7.1 Multiple Output Circuit Control System
ValVue supports HART
®
devices including, the SVI3 with non-zero polling addresses and
supports for multiple SVI3 on the same loop, For Configuring Polling address for Split range
applications, Please refer the SVI3 DTM Manual.
7.7.2 Isolators
Another solution is to use an Intrinsic Safety Isolator for each loop as shown in Figure 39
on page 116. A number of manufacturers make suitable isolators designed for use with
HART
®
output circuits. Using an IS Isolator allows up to three SVI3 to be operated from a
single 4
-
20 mA DCS output
.
Each isolator has a low compliance voltage input
requirement and a high voltage output capacity
.
Up to three isolators can be connected in series to a single controller output and each of
them can drive a positioner
.
Isolators are used to provide compliance voltage and isolation
even in installations not requiring intrinsic safety
.
Consult the manufacturer for detailed
installation instructions.
The HART
®
loop address of each device must be set to 1, 2, and 3 (or other non-zero
values) to allow a HART
®
master to recognize each SVI3 when connected to all three
devices on the safe area side of the multiple isolators. When using multiple isolators, do
not use
0
for any of the positioners. A
0
causes HART
®
masters to stop searching for
additional positioners.
