MQTT & Sparkplug B IoT Telemetry Protocol

MQTT enables distributed RFID reader networks, smart lockers, and handheld scanners to publish clean tag discovery events, antenna health telemetries, and sensor states over lightweight TCP channels to central brokers (EMQX, HiveMQ, AWS IoT Core, Azure IoT Hub).

Layer / Stack

Application / Messaging (TCP / TLS)

Default Port / Freq

TCP 1883 (Plain) / 8883 (TLS/MQTTS)

Throughput / Speed

Sub-15ms message delivery over WAN/Cloud brokers

Standard Body

OASIS MQTT v3.1.1

Core Protocol Architecture & Specifications

✓ Publish/Subscribe topic hierarchies: rfid/readers/{readerId}/tags/read and rfid/lockers/{lockerId}/door/state
✓ QoS 0 (At most once), QoS 1 (At least once with local SQLite buffer), and QoS 2 (Exactly once)
✓ Last Will and Testament (LWT) for instant offline detection of edge gates and dock door portals
✓ Sparkplug B payload standardization for industrial SCADA and unified namespace (UNS) architectures
✓ Bi-directional commands: trigger instant relays, GPIO stack lights, and solenoid door unlocks

OpenRFID Standardized MQTT Tag Discovery Payload Schema

json

{
  "topic": "rfid/facility_delhi_hub/portal_dock_04/tags/read",
  "qos": 1,
  "retain": false,
  "timestamp": 1727539200000,
  "reader": {
    "id": "FX9600-DOCK04",
    "ip": "192.168.1.140",
    "firmware": "v3.10.30"
  },
  "tag": {
    "epc": "E28011606000020468E712AB",
    "tid": "E28011602000700468E712AB",
    "antenna_port": 2,
    "rssi_dbm": -52.4,
    "read_count": 14,
    "frequency_mhz": 866.3,
    "phase_angle_rad": 3.1415
  },
  "motion": {
    "direction": "INBOUND",
    "confidence_score": 0.985
  }
}

Verified Hardware Implementations

Our engineering team has thoroughly tested and validated MQTT & Sparkplug B across the following reader models, embedded modules, and smart transponders:

Zebra FX9600 Onboard MQTT Chainway Smart RFID Lockers OpenRFID Edge Agent Raspberry Pi / Industrial IPC Gateways

Target Deployments

Smart tool & medical lockers
Distributed multi-facility warehouse monitoring
Cold-chain vaccine tracking
Cloud ERP event streaming

Deploy with OpenRFID

Integrate MQTT & Sparkplug B into your ERP, warehouse software, or custom mobile app with pre-built C# / C++ drivers.

Download Driver Plugins Request Architecture Consultation

Related Protocols

Low Level Reader Protocol (LLRP v1.0.1 / v1.1)

Transport & Application (TCP)

EPC Gen2 & ISO/IEC 18000-63 (RAIN RFID)

Physical & Data Link (860–960 MHz UHF)

Modbus TCP & Modbus RTU Industrial PLC Protocol

Fieldbus / Industrial Ethernet (TCP 502 / RS485)

How does MQTT handle network disconnects at warehouse dock doors?

Our OpenRFID Edge middleware buffers unsent reads in a local zero-latency SQLite database. When the MQTT broker connection is restored, it bursts queued tag events with their original hardware timestamps, guaranteeing zero data loss.

← Back to All Protocols & Standards Explore RFID Engineering Calculators →