Polarity; Figure 28: External Alarm Schematic - Fourier DataNet User Manual

- + - +
Alarm device Alarm device
(e.g. siren) (e.g. siren)

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.
- -
+ +
Relay Relay
- -
+ +
54
+ +
3-4 V battery 3-4 V battery
to power relay to power relay
- -