Register 32064 always reads zero even during daylight.

The SUN2000 reports zero on register 32064 when the inverter is in standby or offline mode, such as before sunrise or after a fault trip. Confirm the inverter status indicator is green and that DC string voltage is present before concluding there is a communication error.

The gateway connects but no register values appear at all.

Modbus TCP must be explicitly enabled in the inverter's internal settings menu, not just on the Smart Dongle side. Also verify the port: older firmware uses port 502, while newer firmware versions use port 6607. Try both before suspecting a network issue.

Energy values look implausibly large or never increment.

Register 32106 returns a raw uint32 value with a gain of 100, meaning the actual energy in kWh is the raw value divided by 100. If your portal shows raw counts, apply this scaling factor. The register is cumulative and never resets, so small daily increments are normal at low irradiance.

Connection drops intermittently or returns timeout errors.

The SUN2000 Modbus TCP interface can become unresponsive if polled too aggressively. Increase the inter-poll delay to at least 500 milliseconds and set the connection timeout to 1000 milliseconds or more. Also check that the Smart Dongle firmware is up to date, as older versions are known to drop connections under continuous polling.

Free Modbus template: Huawei SUN2000 Hybrid Inverter (pv)

The Huawei SUN2000 Hybrid Inverter is a residential and light-commercial PV inverter that converts solar DC power to AC and, in hybrid configurations, coordinates battery storage. This ModbusCloud template connects to the SUN2000 via Modbus TCP and reads two key registers: DC input power across all PV strings and total cumulative energy yield since commissioning. With these values in your portal you can track generation output continuously, verify inverter uptime, and build long-term yield reports without relying on the FusionSolar cloud.

Name	Address	Function	Type	Unit	Access
power Total DC input power from all PV strings, in watts.	32064	FC03	int32	W	R
energy Cumulative AC energy generated since commissioning, in watt-hours.	32106	FC03	uint32	Wh	R