Security Fog + Ajax Integration
Ajax is one of the most common modern alarm systems in EU and growing U.S. retail. Integrating security fog into an Ajax ecosystem is straightforward via the Hub’s wired-relay output: fog fires on verified two-sensor activation from your existing Ajax sensors, with no parallel alarm system needed. This guide walks through the wiring, app control, and setup.
Why pair fog with Ajax
Ajax is excellent at the detection-and-notification layer — wireless sensor reliability, app-based remote management, professional monitoring integration. What Ajax doesn’t do is physically intervene during the 60-300 second window between alarm and police response. Adding security fog to the existing Ajax stack:
- Reuses your existing Ajax sensors as the fog trigger source — no parallel sensors needed
- Inherits Ajax’s two-sensor verification logic for low false-discharge rates
- Integrates with Ajax app for remote arming/disarming of the fog system alongside the alarm
- Maintains your existing Ajax monitoring contract — no new central-station relationship required
How the integration works
Ajax Hub (Hub 2 / Hub 2 Plus / Hub Hybrid) outputs alarm events to wired-relay accessories. The security fog system listens on its IN+/IN- dry-contact terminals for that relay closure:
- Ajax sensor (DoorProtect, GlassProtect, MotionProtect) trips
- Hub verifies via two-sensor activation logic
- Hub triggers a programmable scenario that closes a wired relay (Relay or WallSwitch device)
- Relay closes the fog unit’s IN+/IN- circuit
- Fog discharges within 5-10 seconds
- Hub continues sending the alarm signal to monitoring in parallel
Wiring & setup steps
Standard Ajax + fog wiring:
- Mount the fog unit per the standard install guide (see installation).
- Pair an Ajax Relay or Ajax WallSwitch device with the Hub through the Ajax app.
- Run a two-conductor low-voltage wire from the relay’s NO contacts to the fog unit’s IN+/IN- terminals (max 50 m at 18 AWG).
- In the Ajax app, create a Scenario: when any alarm zone activates with verified status, switch on the relay for 2 seconds.
- Test the integration: manually trigger a test alarm from the Ajax app and verify the fog discharges.
- Document the setup for your insurance broker and fire marshal.
App control & arming
Ajax app capabilities relevant to the fog integration:
- Arm/disarm the entire system including fog with one button
- Stay-home and night modes that arm perimeter sensors but keep interior PIRs disarmed (so movement inside doesn’t false-fire fog)
- Per-zone scheduling so the fog only arms during after-hours windows
- Supervisor-only credentials for manual fog discharge during armed-encounter scenarios
- Real-time push notifications when fog deploys, even if you’re offsite
Setup considerations
- Use a wired relay, not a wireless Socket: the wired connection prevents radio interference from blocking the fog trigger during a sophisticated attack.
- Test the verification logic monthly: Ajax allows easy test-mode triggering. Confirm fog fires within 10 seconds and only on verified events.
- Configure the Tamper zone: wire the fog unit’s housing-tamper switch back to a dedicated Ajax zone so attempted defeat of the fog unit triggers fog deployment.
- UPS-backed power: connect the fog unit to a UPS-backed circuit so it remains live during power-cut attacks; the Ajax Hub already runs on its own battery backup.
See also: generic alarm integration · installation · integrate with existing system · buyer’s guide.
Frequently asked questions
Will Ajax central station know the fog deployed?
Yes if you wire a return signal from the fog unit's tamper or activation contact back to an Ajax zone. Then the Hub reports both the alarm event and the fog deployment event to your monitoring contract.
Does Ajax officially support security fog integration?
Ajax doesn't sell fog systems but their wired-relay device family explicitly supports third-party output devices including security fog units. This is a standard installer practice in EU markets where Ajax penetration is high.
Will this work with Ajax Hub Hybrid wired-zone configurations?
Yes. Hub Hybrid wired inputs and outputs work the same way as the wireless equivalents from the fog system's perspective. Some installers prefer Hub Hybrid for fog integration because the wired output is faster than the wireless relay path.
Can the fog system fire via the Ajax mobile app manually?
Yes. Create a scenario triggered by a manual button in the app (or by a button on a paired KeyPad Plus). This is the typical configuration for daytime armed-encounter scenarios — staff press the button via app or KeyPad.
