Step 1
Connect the relay & I/O Port
Wire the following terminals:
- I/O Port 3 on the Olarm HUB to the Relay's (negative) –
Note: When I/O Port 3 is triggered, it has a negative trigger which energises the relay coil. (ie. the I/O Port is pulled down to GND applying GND to the Relay's negative terminal)
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Step 2
Connect the Relay, Siren, & Power supply
Wire the following:
- Relay (Positive +) to the 12V Power Supply (Positive +)
- Relay COM to the 15/30W Siren's (Positive +)
- Siren (Negative -) to the 12V Power Supply (Negative -)
- Bridge the Relay NO to the Relay's (Positive +)
When the relay energises, the NO contact closes onto COM, completing the circuit and powering the siren.
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Step 3
Common GND between the HUB & Power Supply
Ensure the GND on the Olarm HUB is connected to the GND on the Power Supply.
Before powering up the installation, check each connection against the complete wiring diagram below.
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Step 4
Configure I/O Port 3 for the External Siren
In the Olarm APP:
- Tap the Menu Icon (≡) in the top-right corner
- Select System Settings.
- Select HUB I/O's.
- Select I/O Port 3.
- Toggle Enable to switch the I/O Port on.
- Select Control something.
- Under What do you want to control?
- Use the dropdown and select Siren.
- Use the dropdown and select Siren.
- Select Advanced setup.
- Select Normally Open as the default state.
- Once complete, select the back arrow (top left).
- Give the siren I/O Port a name.
Step 5
Configure the Siren behaviour Per Area
In System Settings:
- Select Areas.
- Go into the relevant Area.
- Scroll down to Siren Settings.
- Ensure the Alarm Tone has been Enabled.
- Select & adjust the Audible Alarm Tone duration
- This sets how long the siren will trigger for when in alarm.
- Adjust the Siren behaviour as per your requirements
- Sound when armed
- Sound when disarmed
- Sound for countdown
Ensure these steps are done per area for the external siren.
Step 6
Disable the Internal Siren (Optional)
Should you not require the Internal Siren for arming/alarm state. You are able to turn off the internal siren by reducing its volume to 0%.
In System Settings:
- Select Siren Setup
- Adjust the Siren Volume
- Select 0% to disable the Internal Siren
Note: The Siren volume only configures the Internal Siren, NOT the External Siren volume.
Step 7
Test the Siren & System
With the wiring and configuration complete, perform a full end-to-end test. Arm and disarm the linked area (or trigger the relevant status) from the Olarm APP.
Confirm that:
- The relay audibly clicks (energises).
- The siren sounds correctly based on the area's status.






































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