Mennekes AbstractMennekes
The Mennekes AbstractMennekes template integrates Mennekes AMTRON EV charging stations into the ModbusCloud portal over Modbus TCP. The template covers the core energy-management interface: register 1000 is used both to read the active EMS current limit and to write a new current limit setpoint, giving an energy manager direct control over how much current the wallbox delivers to the connected vehicle. Monitoring this single register pair lets installers verify that load-management commands are accepted and track charging current over time without additional hardware.
- Protocol
- Modbus TCP
- Connection
- Ethernet, Modbus TCP
- Registers
- 2, read and write
- Brand
- Mennekes
- Last updated
Registers (2)
1 read, 1 write
| Name | Unit | Access | Address (Hidden until you enter your email) | Function (hidden) | Type (hidden) |
|---|---|---|---|---|---|
| ems_current_limit | A | Read | |||
| set_current_limit | A | Write |
Loading registers…
Send your device list
If a device is not in the library yet, we build the template for free as soon as we have the register data.
Use cases
- Monitor the active EMS current limit to verify that load-management commands are applied correctly in real time.
- Write a reduced current limit setpoint during peak grid-demand periods to prevent local circuit overloads.
- Compare the read-back current limit value against the last written setpoint to confirm the wallbox accepted the command.
- Alert on a current limit that stays at zero to detect a lost EMS connection or a stalled charging session.
- Track current limit setpoint changes over time to audit dynamic load-management behaviour across multiple charging points.
Installation
Enable the Modbus TCP server on the Mennekes AMTRON wallbox by opening the device web interface, navigating to the communication or Modbus section, and activating the Modbus TCP server. Firmware version 1.13 or later is required for HCC3-based models.
Connect the AMTRON wallbox to the same Ethernet network as the ModbusCloud Gateway, using the default Modbus TCP port 502. For HCC3-based models (XTRA, PREMIUM) the unit ID is 255; for RTU-bridged or satellite units it is commonly 50.
In the ModbusCloud portal, add your Gateway, then import the Mennekes AbstractMennekes template and assign the correct unit ID and the IP address of the wallbox.
Verify the connection by reading register 1000 (ems_current_limit) in the portal's live register view. A non-zero or changing value confirms the wallbox is responding correctly.
Things to watch for
The gateway connects but register 1000 always returns zero. Why?
A zero on register 1000 usually means no EMS current limit has been set yet, or the wallbox is not in EMS/energy-manager mode. Ensure the Modbus register set is configured to the correct profile in the wallbox settings, and that the EMS control mode is active. Some models require the register set to be set to the manufacturer's own Modbus profile, not a generic one.
Modbus TCP connection times out even though the wallbox is reachable by ping. What now?
Some Mennekes AMTRON models only allow one simultaneous Modbus TCP client. If another system (an EMS, openHAB, or evcc) is already connected, the ModbusCloud Gateway will be refused. Disconnect the other client, or check whether the wallbox firmware supports multiple concurrent connections. Also confirm that the Modbus TCP server is explicitly enabled in the wallbox web interface.
Writing a new current limit to register 1000 has no effect on charging. Why?
To control charging current via Modbus, the wallbox must be in EMS satellite mode. Depending on the model, this requires the correct DIP-switch setting (DIP 5 on the S1 baseboard row) and a periodic master heartbeat sent to the wallbox. Without the heartbeat, the wallbox reverts to its configured fallback current. Check the model-specific Modbus specification for the heartbeat register and interval.
Are there risks to writing register 1000 with arbitrary current values?
Yes. Writing a current limit above the cable or circuit rating can trip protection devices or damage equipment. Writing zero may stop an active charging session unexpectedly. Always stay within the rated minimum (6 A) and maximum current for the installation. Test setpoint changes with a vehicle connected and monitor the wallbox status. Confirm with the site electrician before deploying automated setpoint control.
Want to see how it works?
