Circontrol eHome RS

Use cases

• Monitor vehicle connection state and charging intensity on a live cloud dashboard for residential customers.
• Create an alert when an error code appears on the eHome RS so you can respond before the customer calls.
• Remotely stop or disable a charge session during peak grid demand to avoid capacity tariff penalties.
• Log historical load counter data to generate monthly charging reports for fleet or household billing.
• Adjust maximum charge intensity remotely to match available solar surplus on a PV-equipped home.
• Combine EV charger data with energy meter readings in one dashboard for a complete site energy overview.

Installation

1. 1Connect the ModbusCloud gateway RS-485 port (A and B terminals) to the Modbus RTU port on the Circontrol eHome RS, observing correct polarity.
2. 2Set the eHome RS Modbus slave address to match the address configured in the ModbusCloud template, and confirm the baud rate is set to 9600.
3. 3Power on both the gateway and the charger, then verify communication by checking for valid register readings in the gateway diagnostics.
4. 4Import the Circontrol eHome RS template in the ModbusCloud platform and assign it to the corresponding gateway and slave address.
5. 5Verify that key readings such as State of Vehicle and Intensity max. station appear correctly on the cloud dashboard.
6. 6Test a write command, for example adjusting Intensity Charge, to confirm bidirectional communication is working.

Things to watch for

01

The gateway cannot read any registers from the eHome RS. What should I check?

Verify that the RS-485 wiring polarity (A to A, B to B) is correct and that a 120 ohm termination resistor is placed at the end of the bus if the cable run is long. Also confirm the slave address and baud rate (9600) match on both devices.

02

Can I use Modbus TCP instead of Modbus RTU with this charger?

The eHome RS supports Modbus RTU only. You need a gateway with an RS-485 serial port. Modbus TCP is not available on this model.

03

What data type do the registers use?

All registers are uint16 (unsigned 16-bit integer). No special byte order or scaling factors are documented beyond the default settings.

04

Is it safe to write to control registers while a vehicle is actively charging?

Yes, you can adjust charge intensity or stop a session while charging is in progress. The charger will apply the new setting immediately. Use caution with the Disable Charge Station register as it will prevent any new sessions until re-enabled.

Registers (14)

14 read / 6 write

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