Product Specifications
2
0
1
8
-1
2
25
Resistor network
Most I/O modules have a line fault detection function that can recognize a lead breakage or a
short circuit.
If binary I/O modules are used, for example with a mechanical contact, an additional resistor
network must be installed to ensure that the line fault detection function can work correctly.
Using the additional resistor network, the electronics can distinguish between a closed switch
and a short circuit.
To do this, the resistor network must be positioned directly on the field device.
Figure 2.20
Dimensions of the F-NR2-Ex1 resistor network
Figure 2.21
Block diagram of the F-NR2-Ex1 resistor network
F-NR2-Ex1
27
35
150
Ø1
5.5
Zone 1, 2
F-NR2-Ex1
10 kΩ
1.5 kΩ
2-
1+
-
+
