54
- +
Relay
-
+
-
+
Alarm device
(e.g. siren)
+
-
3-4 V battery
to power relay
- +
Relay
-
+
-
+
Alarm device
(e.g. siren)
+
-
3-4 V battery
to power relay
Figure 28:
External alarm schematic
•
+ from DNR900 goes to – of the Relay inputs
•
+ of Relay input goes to battery that powers the Relay
•
Load inputs of the Relay go to the Alarm device e.g. siren,
lights, etc.
•
- of the battery goes to – of DNR900.
Note:
Maximum load of the Relay is 50 mA, 3 V.
Refer to
Appendix A: DataNet Specifications for the full
external alarm output specification.
3.7.7.
Polarity
Current, voltage, thermocouples and user defined sensors
have distinct polarity. Be careful to connect them in the right
polarity.