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Structure and function
Input/output configuration options (secondary side)
3
42 | 72
Building Technologies
009122_h_en_--
Fire Safety
2016-05-04
3.4.4.3 Reverse-polarity monitoring
With this type of monitoring, the control voltage polarity is reversed in relation to
that of the monitoring voltage. The monitoring resistor is 3.3 k and parallel with
the load. The load must be isolated from the monitoring voltage by means of a
diode.
Reverse-polarity monitoring must always be used in the case of electronic loads.
Circuit featuring reverse-polarity monitoring
Figure 11: Circuit for control lines with reverse-polarity monitoring
1
Internal fuse (0.7 AT)
2
External fuse on the output (1 AT or 1.5 AT)
The figure shows the relay in the dropped-out state, i.e., the monitored state.
See also
Calibrating the control line [ 57]
Control without confirmation [ 43]
Control with confirmation [ 44]
Printed circuit board view [ 21]
Adjustment elements [ 27]
24 V
0 V
10 V
0 V
I/O
FDCIO223
+
1
2
3.3 k