Hager Hager XEM with EMC flow R2 (pv)
The Hager XEM with EMC flow R2 (pv) is an energy management controller in the Hager flow home energy management system, used to monitor photovoltaic production in residential and light-commercial installations. The XEM470 EMC connects over Ethernet and exposes data via Modbus TCP. This template reads the PV active power register (address 4126), giving your ModbusCloud portal a live view of solar generation output. With this single measurement in the cloud, installers and building owners can track real-time PV yield, feed data into dashboards, and verify that solar generation matches design expectations.
- Protocol
- Modbus TCP
- Connection
- Ethernet, Modbus TCP
- Registers
- 1, read only
- Brand
- Hager
- Last updated
Registers (1)
1 read, 0 write
| Name | Unit | Access | Address (Hidden until you enter your email) | Function (hidden) | Type (hidden) |
|---|---|---|---|---|---|
| power | W | Read |
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 live PV production power to confirm the solar installation is generating as expected at any time of day.
- Track PV output trends over days and weeks to detect gradual performance degradation or shading issues.
- Alert on unexpected drops in power register readings during peak sun hours to catch inverter or wiring faults.
- Compare PV power readings against consumption data from other meters to calculate self-consumption ratio.
- Report daily and monthly solar yield figures to building owners or facility managers via the ModbusCloud portal.
Installation
Verify that the Hager XEM470 EMC is connected to the local LAN via its Ethernet port and that its cloud pairing is complete, with all three status LEDs showing green.
Connect the ModbusCloud Gateway to the same LAN segment as the XEM470 EMC so both devices share IP connectivity on the same subnet.
In the ModbusCloud portal, add the Gateway, import the Hager XEM with EMC flow R2 (pv) template, and set the unit ID to match the XEM470 Modbus slave address configured under its communication settings.
Perform a spot-check by reading register 4126 in the portal live view during daylight hours and confirm the returned value matches the PV production shown in the Hager flow app.
Things to watch for
Register 4126 always returns zero even in sunshine. Why?
The XEM470 EMC reports PV power only when a PV energy meter is correctly paired and active in the flow system. Verify in the Hager flow portal that the PV meter component is added, paired, and showing live data. If the meter is unconfigured or offline, register 4126 will read zero regardless of actual generation.
The gateway connects to the XEM470 but reads return timeout errors. What now?
The XEM470 communicates over Ethernet (Modbus TCP). Confirm the device IP is reachable from the ModbusCloud Gateway (ping test), that no firewall rule blocks TCP port 502, and that the XEM470's NET LED is solid green rather than flashing orange or red, which would indicate a network or cloud connectivity fault.
Power values look inconsistent or jump unexpectedly. What causes this?
Register 4126 is typed as uint32, spread across two consecutive 16-bit Modbus holding registers read via FC3. Ensure your Modbus client uses big-endian (high word first) byte order when assembling the 32-bit value. Incorrect word order causes the high and low words to swap, producing wildly incorrect readings that still pass range checks.
The NET LED on the XEM470 flashes orange or red. Can I still poll Modbus?
An orange or red NET LED means the EMC has lost its connection to the Hager cloud or has an IP configuration fault. Local Modbus TCP communication may still function if the device has a valid IP address, but the energy data from the PV meter may stale or freeze. Resolve the network issue first: check DHCP lease, subnet mask, and gateway settings on the XEM470 embedded webserver.
Want to see how it works?
