- 28 -
As a final remark, we can observe that, whatever is the field-loops isolation or connection, a single capacitor fault
plus any other possible additional fault within the MUX 2700 never results in any errors induced from the MUX 2700
on any 4-20mA loop.
12.5 Conclusions
By this note, it was possible to clarify how the MUX 2700 isolation structure is such to guarantee both an high level
of application flexibility and a good reliability and fault tolerance (as for induced errors).
The presence of two series capacitors on each 4-20mA loop was discussed and the advantages of the solution
explained.
Some safety related issues were finally discussed, showing that, with a minimum of application-related analysis,
the MUX 2700 can be designed so to minimise the probability of any electrical feedback on the connected 4-20mA
loops.
IM-ENG-116/GB
A
+
+
CHx
+
CHy
+
24 Vdc
R < 300 Ohm
Tx
Tx
R
R
GND
F
IG
. 10
C
OMMON
-
POINT
F
IELD
L
OOPS
C
ONFIGURATION
