The Four-Stage Security Response Chain
Every home security system — from a basic wireless alarm to a fully professional monitored system — operates on the same four-stage chain: Detect — Communicate — Alert — Respond. Understanding each stage helps you identify gaps in your current security setup and choose the right products to fill them.
Stage 1: Detect — A sensor identifies a threat
(door opened, motion detected, glass broken).
Stage 2: Communicate — The sensor transmits a
signal to the alarm hub (via 433MHz RF).
Stage 3: Alert — The hub activates the siren +
sends push notification + sends GSM SMS/call.
Stage 4: Respond — Homeowner or local proxy
verifies the threat and takes action (call barangay, PNP).
How Security Sensors Detect Threats
Door and Window Magnetic Sensors
A door sensor consists of two parts: a main body (containing a reed switch) and a small magnet. When the door is closed, the magnet holds the reed switch closed — the circuit is complete and the sensor reports "closed/normal" to the hub. When the door opens, the magnet moves away from the reed switch, breaking the circuit — the sensor immediately transmits a "triggered" signal to the hub via 433MHz RF signal. The signal travels through air at the speed of light — trigger-to-hub communication takes less than 0.1 seconds.
PIR Motion Detectors
PIR (Passive Infrared) sensors detect changes in infrared radiation — body heat. The sensor has a pyroelectric element covered by a Fresnel lens that divides the detection zone into segments. When a person moves through the zone, their body heat (approximately 37—C) sweeps across these segments, creating a rapid change in the infrared signal detected by the sensor. This change triggers the alarm signal. The Fresnel lens design creates the characteristic "beam pattern" you see in PIR specifications: typically 10-10 meters at a 90-110x horizontal angle when mounted at 2.2 meters height.
Pet-immune PIR sensors use a modified lens that creates a detection pattern that begins 50-60cm above the floor — animals walking on the floor are below the detection threshold, while a standing human is well within the zone. This technology prevents false alarms from dogs, cats, and small animals common in Filipino households.
Camera Motion Detection (AI)
Modern WiFi cameras like the CI-400 use AI software-based motion detection rather than (or in addition to) PIR sensors. The camera's processor continuously analyzes the video stream and identifies pixels changing between frames. Standard motion detection triggers on any movement — including shadows, ceiling fans, and trees blowing in the wind. AI person detection filters this — it recognizes the shape and movement pattern of a human body specifically, dramatically reducing false alert rates.
How the Alarm Hub Works
The central hub (alarm panel) is the brain of the security system. It continuously listens for signals from all enrolled sensors using the 433MHz or 915MHz radio frequency band. When it receives a trigger signal from a sensor, it executes its programmed response sequence simultaneously:
- Activates the indoor siren (105dB — heard up to 50 meters away through solid concrete walls in Philippine-standard construction).
- Sends a push notification to the Tuya Smart app on all enrolled smartphones (requires WiFi).
- On GSM-equipped models (AH-GA Series), dials the first number on the GSM contact list via the built-in SIM card module.
- Sends SMS text messages to all enrolled phone numbers simultaneously.
- Records the event timestamp in the panel's local log — accessible via app for audit trail.
The GSM Alert Chain — Philippines Context
This is the most important process to understand for OFW families. When the AH-GA200 GSM panel triggers at a Philippine home:
- 0 seconds: Door sensor opens — 433MHz signal reaches hub in <0.1 seconds.
- 0-15 seconds: Entry delay (if configured) counts down — allows household members to disarm before siren activates.
- 15 seconds: Hub activates 105dB siren and simultaneously initiates GSM dial sequence.
- 20-25 seconds: SMS messages sent to all 6 enrolled Philippine numbers (arrival time depends on network congestion — typically 5-30 seconds via Globe/Smart/DITO).
- 30-60 seconds: Phone call to Contact 1 connects. If unanswered after 30 seconds, automatically calls Contact 2.
- Contact 1-6 sequence continues until someone answers or all contacts are exhausted. Process then restarts.
How Camera Alerts Work
The camera alert sequence on HomeSecurityPH CI/CO Series cameras:
- AI motion detection identifies a person in the camera frame.
- Camera captures a 15-second event video clip and a snapshot image.
- Clip and snapshot are uploaded to Tuya cloud servers (if cloud storage is enabled) and stored locally to MicroSD simultaneously.
- A push notification is sent to all linked Tuya Smart app accounts — includes the snapshot image in the notification preview so you can see the event immediately without opening the app.
- Tapping the notification opens the live camera feed — you see the situation in real time and can activate two-way audio to speak to the person on camera.