The ThingsBoard IoT Gateway is an open-source solution that allows you to integrate devices connected to legacy and third-party systems with ThingsBoard.
ThingsBoard is an open-source IoT platform for data collection, processing, visualization, and device management. See What is ThingsBoard? if you are new platform user.
Gateway features
The ThingsBoard IoT Gateway provides the following features:
- MQTT connector to control, configure and collect data from IoT devices that are connected to external MQTT brokers using existing protocols.
- OPC-UA connector to collect data from IoT devices that are connected to OPC-UA servers.
- Modbus connector to collect data from IoT devices that are connected through Modbus protocol.
- BLE connector to collect data from IoT devices that are connected using Bluetooth Low Energy.
- Request connector to collect data from IoT devices that have HTTP(S) API endpoints.
- CAN connector to collect data from IoT devices that are connected through CAN protocol.
- BACnet connector to collect data from IoT devices that are connected through BACnet protocol.
- ODBC connector to collect data from ODBC databases.
- REST connector to create endpoints and collect data from incoming HTTP requests.
- SNMP connector to collect data from SNMP managers.
- FTP connector to collect data from FTP server.
- Socket connector to collect data from IoT devices that are connected through TCP/UDP protocol.
- XMPP connector to collect data from IoT devices that are connected through XMPP protocol.
- OCPP connector to communicate between Charge Point and Central System.
- Custom connector to collect data from IoT devices that are connected by different protocols. (You can create your own connector for the required protocol).
- Persistence of collected data to guarantee data delivery in case of network or hardware failures.
- Automatic reconnect to the ThingsBoard cluster.
- Simple yet powerful mapping of incoming data and messages to unified format.
Architecture
The IoT Gateway is a software component that is designed to run on a Linux based microcomputers that support Python 3.7+. The main components of ThingsBoard IoT Gateway are listed below.
Connector
The purpose of this component is to connect to external system (e.g. MQTT broker or OPC-UA server) or directly to devices (e.g. Modbus, BLE or CAN). Once connected, the connector either poll data from those systems or subscribe to updates. Poll vs subscribe depends on the protocol capabilities. For example, we use subscription model for MQTT connectors and polling for Modbus and CAN. The connector is also able to push updates to devices either directly or via external systems.
It is possible to define your own connector using the customization guide.
Converter
Converters are responsible for converting data from protocol specific format to/from ThingsBoard format. Converters are invoked by Connectors. Converters are often specific to protocol supported by Connector. There are uplink and downlink converters. The uplink converter is used to convert data from specific protocol to ThingsBoard format. The downlink converter is used to convert messages from ThingsBoard to specific protocol format.
It is possible to define your own converter using the customization guide.
Event Storage
The Event Storage is used to temporary store the telemetry and other events produced by Connectors until they are delivered to ThingsBoard.
The Event Storage supports two implementations: in-memory queue and persistent file storage.
Both implementations make sure that your device data is eventually delivered in case of network outages.
In-memory queue minimizes the IO operations but may lose messages in case of gateway process restart.
Persistent file storage survives the restart of the process but executes IO operations to the file system.
ThingsBoard Client
The Gateway communicates to ThingsBoard via MQTT protocol and uses API described here.
ThingsBoard Client is a separate thread that polls Event Storage and delivers messages once connection to ThingsBoard is active.
ThingsBoard Client supports monitoring of the connectivity, batching the events for performance improvement and many other features.
Gateway Service
The Gateway Service is responsible for bootstrapping the Connectors, Event Storage and ThingsBoard Client. This Service collects and periodically reports statistics to ThingsBoard about incoming messages and connected devices. Gateway Service persists list of connected devices to be able to re-subscribe to device configuration updates in case of the restart of the gateway.
