16
4.3.5.
External Alarm Output
The OM-DAQLINK system supports connection of an external alarm e.g. siren, audible alarm, to
In-1 of the OM-DAQLINK-TEMP and OM-DAQLINK-TEMPRH data loggers.
When connected to the logger, the external alarm will be activated only when that logger is in
alarm status.
Once there is no alarm status, the external alarm will be deactivated.
Data Logger External Alarm
In-1 of the OM-DAQLINK-TEMP and OM-DAQLINK-TEMPRH serves either as a standard
sensor input or as an external alarm output. Ensure the logger is connected to AC power if
connected to an external alarm.
Configure In-1 as
Alarm Normally Open
or
Alarm Normally Closed
in the logger Setup
window in the DataSuite software.
Normally Open
will result in the alarm being activated during alarm status (the circuit will be
closed).
Normally Closed
will result in the alarm being activated when logger is not in alarm and
therefore deactivated when there is an alarm (the circuit will be opened).
Connect In-1 to your external alarm device and connect the logger to AC power.
Use the
Alarm Setup
tab in the Setup dialog to define the logger alarm settings. If these
settings are breached then the alarm will be activated.
External Alarm Schematic
See the schematic below explaining how to hook up an external alarm to the OM-DAQLINK unit.
Figure 12:
External alarm schematic
+ from OM-DAQLINK unit goes to
– of the Relay inputs
+ of Relay input goes to battery that powers the Relay
- +
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
