Custom Flows via Edge (Node-RED)
Build custom data flows directly on the EpiSensor gateway using Node-RED visual programming.
Visual Programming at the Edge
Node-RED is an open-source, flow-based programming tool originally developed by IBM. It provides a browser-based visual editor where you connect pre-built nodes to create data processing pipelines without writing traditional code. EpiSensor Edge is built on Node-RED and runs directly on the ZGW-10 Gateway, giving you a powerful programming environment right at the data source.
With Edge, you can transform, filter, enrich, and route energy data before it leaves the gateway. This reduces cloud bandwidth and processing costs, enables local decision-making with sub-second latency, and lets you integrate with protocols and platforms that are not covered by the gateway's built-in connectors.
How It Works with EpiSensor
Edge runs as a Docker container on the ZGW-10 gateway's embedded Linux operating system. It has direct access to all sensor data flowing through the gateway via internal MQTT topics. When a sensor reading arrives, it appears as a message in the Edge flow editor, where you can apply any combination of transformation, logic, and output nodes.
The Node-RED ecosystem includes thousands of community-contributed nodes for connecting to databases, APIs, cloud services, industrial protocols, and notification systems. Install additional nodes directly from the npm registry through the Edge palette manager. Flows are deployed with a single click and run persistently on the gateway, surviving reboots and network outages. The Core platform can push and manage Edge flows across your entire fleet of gateways remotely.
Key Features
Visual Flow Editor
Drag and drop nodes to build data pipelines in a browser-based editor. No coding experience required for standard transformations, though JavaScript function nodes are available for advanced logic.
Edge Processing
Process data locally on the gateway before sending it to the cloud. Calculate derived metrics, apply moving averages, filter noise, or aggregate readings to reduce bandwidth.
Thousands of Nodes
Access the full Node-RED library of community nodes. Connect to databases (InfluxDB, PostgreSQL, MySQL), messaging systems (Kafka, RabbitMQ), APIs, email, SMS, and more.
Local Alerting
Set up threshold-based alerts that trigger locally without cloud round-trips. Send notifications via email, SMS, webhook, or control relay outputs for immediate response.
Fleet Management
Develop flows on one gateway and deploy them across your entire fleet via Core. Version-control flows and roll back to previous versions if needed.
Custom Protocol Support
Need to integrate with a protocol not natively supported? Write a custom Node-RED node or use existing community nodes for OPC-UA, KNX, SNMP, and dozens of other protocols.
Use Cases
Data Transformation
Convert raw sensor readings into business-relevant metrics at the edge. Calculate cost per kWh by applying tariff schedules, compute carbon emissions from consumption data, or normalise readings across different meter types.
Multi-Destination Routing
Send different data to different destinations from a single gateway. Route real-time alerts to a webhook, historical data to InfluxDB, and aggregated summaries to an MQTT broker -- all in one flow.
Legacy System Integration
Bridge EpiSensor data to legacy systems that use proprietary protocols, flat-file imports, or FTP-based data exchange. Node-RED's flexibility means virtually any integration is possible.
Getting Started
Edge is pre-installed on every ZGW-10 gateway. Access the flow editor by navigating to the gateway's IP address on the Edge port in your browser. Sensor data is available on internal MQTT topics -- drag in an MQTT input node, subscribe to the sensor topic, and you are ready to start building. Connect transformation nodes, add outputs, and click Deploy.
For your first flow, try subscribing to all sensor data, adding a threshold check with a switch node, and sending an email notification when consumption exceeds a limit. From there, explore the node palette to add database outputs, API integrations, or dashboard visualisations. The EpiSensor team provides starter flow templates for common use cases to accelerate your development.
Ready to Build Custom Flows?
Talk to our team about what you can build with EpiSensor Edge and Node-RED.