What is the Stekker Edge module?
The Stekker Edge module is a compact industrial gateway installed on-site in the meter cabinet or technical room. The device runs on the Teltonika RUT956, an industrial router specifically designed for reliable deployment in commercial environments.
The Edge module fulfills three core tasks:
- Measure — Real-time reading of energy meters via the Modbus protocol (TCP or RTU). The module reads power, voltage, current and energy consumption at sub-second intervals.
- Communicate — All measurement data is forwarded to the Stekker platform in the cloud via MQTT (a lightweight messaging protocol).
- Control — The platform sends power instructions back to the Edge module, which translates them into commands for local equipment such as charge points and batteries.
Why an Edge module?
The Stekker platform optimizes charging schedules and energy consumption based on real-time data. This requires real-time insight into local energy usage. The Edge module provides that insight:
- Real-time power data — Accurate measurements in Watts, multiple times per second. This enables peak shaving (capping power peaks) without unnecessary safety margins.
- Local sensor data — The module measures not just the grid connection, but also individual charge points, solar panels, batteries and other loads. This creates a complete picture of the energy flows at your site.
- Heartbeat monitoring — The Edge module sends a heartbeat to the platform every few seconds. If no heartbeat arrives for more than 2 minutes, the platform automatically detects that the module is offline. This prevents blind control.
- Automatic registration — On first boot, the Edge module automatically registers with the platform via a boot notification containing its MAC address, hostname and firmware version. No manual configuration in the platform is required.
- Remote firmware updates — The platform tracks which software version each Edge module is running and can roll out updates without anyone needing to be on-site.
Sensor types
Each Edge module is linked to one or more sensors in the Stekker platform. A sensor is a measurement point tied to a specific component of the installation. The following types are supported:
- Grid connection (GridConnection) — The total power at the main connection. This is the basis for peak shaving and capacity management.
- Charge point (ChargePoint) — An individual charging station or charging column.
- Charging connector (ChargingConnector) — A single plug connection on a charge point. Charge points with multiple connectors (e.g., two CCS connections) are measured per connector.
- Solar panels (SolarArray) — The output of a set of solar panels or inverter.
- Battery (Battery) — A stationary storage system. The sensor measures both power and state of charge (SoC).
- Other load (OtherLoad) — All other electrical consumers on the connection, such as lighting, HVAC or production equipment.
- Junction (Junction) — A virtual aggregation point that combines multiple sensors in the energy tree of a site.
Communication
The Edge module communicates bidirectionally with the Stekker platform via MQTT, a lightweight publish/subscribe protocol that works reliably over mobile and unstable connections.
Message types from Edge to platform
- Boot notification — Sent on every (re)start of the module. Contains MAC address, hostname, firmware version and software version. This allows the platform to register the device automatically.
- Heartbeat — Periodic liveness message. If the platform receives no heartbeat for more than 2 minutes, the module is considered offline.
- Power measurement — Current power per sensor in Watts. This is the primary data stream for the energy management system.
- Measurement — Extended measurements with multiple metrics per sensor (e.g., voltage per phase, current, cos phi). Each metric has a name, value and unit.
- Charge status — Charge percentage of a battery or vehicle.
- Network scan — Overview of devices on the local network (IP, MAC address, manufacturer). Helps identify connected energy meters.
- Instruction update — Status update on a previously received control command (accepted, started, completed or aborted).
Message types from platform to Edge
- Power setpoint — Control command with a maximum power in Watts, including start and end time. This is how the platform controls charge points and batteries via the Edge module.
- Power forecast — Expected power profile over time, allowing the Edge module to anticipate future situations.
- Charge target — Charging goal with a desired percentage and time window, distinguished between “direct” (as fast as possible) and “smart” (by a specified time).
- Connect / Disconnect — Signals for connecting and disconnecting a charging connection, including technical parameters such as maximum current, voltage and number of phases.
Security
Each Edge module has unique MQTT credentials (username and password) issued per organization. System accounts with limited read or write permissions are used for platform services. All communication is encrypted.
Installation
Installing an Edge module is straightforward and is carried out by an installer or by the Stekker team:
- Physical placement — The Teltonika RUT956 is mounted in or near the meter cabinet. The device is compact enough for DIN rail mounting.
- Network connection — The module is connected to the local network via Ethernet. As a backup, the device has a 4G modem for automatic failover in case of network outages.
- Connecting energy meters — Via the local network (Modbus TCP) or serial connection (Modbus RTU), the module is connected to the energy meters in the meter cabinet.
- Automatic registration — On first boot, the module sends a boot notification to the platform. The module immediately appears in the Stekker dashboard under the correct organization.
- Sensor mapping — In the platform, sensors are linked to the appropriate components of the installation (grid connection, charge points, solar panels, etc.).
- Remote management — After installation, the module is remotely accessible via a secure SSH tunnel. Firmware updates, configuration changes and diagnostics can all be performed remotely.
