Northbound Applications
Once southbound drivers have collected the data, its destination determines which northbound application to use. EMQX Neuron offers four destinations, each matching a typical plant scenario.
| Use case | Application |
|---|---|
| Send data to the cloud Headquarters or a cloud platform consolidates data from several plants | MQTT · AWS IoT · Azure IoT |
| Connect an IIoT platform (unified namespace) Let the platform model devices automatically, with no config change when devices are added | Sparkplug B |
| Serve upper-level systems SCADA, MES, and configuration software read from the gateway without being modified | OPC UA Server · WebSocket |
| Feed analytics and edge computing Land in a data lake for long-term analysis, or filter and aggregate at the edge first | Kafka · Rules Engine Application |
The first three push data outward. Serving upper-level systems reverses that: on-site systems connect in as clients to read. Support for write-back per category is listed in the table below.
Common steps
The configuration flow is the same for every northbound application:
- Create a northbound application: select the application type and fill in the connection parameters
- Subscribe to southbound data: attach the collection groups to be published
Data is reported per group. One application can subscribe to many groups, and one group can be subscribed by many applications, so the same data can reach a cloud platform, an on-site system, and a data platform simultaneously.
Capability comparison
Application | Direction | Write back | Offline cache | Security |
|---|---|---|---|---|
| MQTT | Push | Write request / response topics | Yes | TLS, mutual auth |
| Sparkplug B | Push | NCMD / DCMD commands | Yes | TLS, mutual auth |
| AWS IoT | Push | Write request / response topics | Yes | Device certificate |
| Azure IoT | Push | Cloud-to-device (C2D) messages | Yes | SAS token, X.509 certificate |
| OPC UA Server | Pull | Client writes the variable node | — | Security policy, certificates, username/password |
| WebSocket | Push | No | — | wss, mutual auth |
| Kafka | Push | No (producer only) | — | SASL, TLS |
| Rules Engine Application | Internal | Neuron sink writes back | — | — |
TIP
Besides northbound applications, EMQX Neuron offers a RESTful API for reading and writing tags — see HTTP API.
Next steps
- Process data before publishing — filter, downsample, aggregate, or normalize field names. See Data Processing.
- Confirm data is leaving — check
send_msgs_totalon the application card. See Subscribe to Southbound Data · Verify. - Monitoring and alerts once live — see Operations.