Can I mix sensor brands on the same VMS?
Yes, if they all support ONVIF, MQTT, or REST APIs. However, integrators report smoother deployments and faster troubleshooting when 80%+ of sensors share a common protocol and brand ecosystem. Test interoperability with your VMS vendor before committing to a mixed-brand architecture.
How many sensors can a single PoE switch support?
Depends on switch wattage and per-port power budget. A 250W PoE+ switch typically handles 15–20 full-power devices; lean sensors (door contacts, simple thermal) can pack 40+ per switch. Calculate total watts needed, then add 30% headroom for future expansion. See PoE budget planning for detailed math.
What's the difference between MQTT and ONVIF for sensor integration?
ONVIF is a camera-centric standard; best for VMS-to-sensor events (motion, door open, alert). MQTT is a lightweight pub-sub protocol that works across IoT platforms (VMS, HVAC, lighting, ERP systems). Use ONVIF for tight surveillance workflows; MQTT for loosely coupled multi-system environments.
Do wireless sensors need a mesh network, or can they talk directly to the VMS?
Most wireless sensors (Zigbee, Z-Wave, LoRaWAN) require a hub or gateway to reach IP networks and the VMS. Mesh networks self-heal around dead zones but introduce latency (100–500ms). For real-time door alerts, direct wired or PoE sensors are more reliable.
How do I prevent false water-detection alarms?
Place sensors at the lowest point of potential pooling (floor corners, under pipes), not on exposed surfaces where humidity or condensation triggers false positives. Use hysteresis or debounce logic in the controller—require 30+ seconds of wet contact before raising an alert. Test during HVAC commissioning to validate placement.
Can sensors integrate with legacy alarm panels, or do I need a new system?
Legacy hardwired alarm sensors (door contacts, glass breaks) can be bridged to IP via an I/O controller or relay gateway that converts discrete inputs to network events. This hybrid approach defers replacement costs while enabling VMS alerting and modern analytics.