The gateway connects but all register values show as zero or NaN.

The SMA SHM 2.0 Modbus interface must be explicitly activated in Sunny Portal under grid management services. If the interface has not been enabled, or a firmware update reset the setting, the device will accept the TCP connection but return NaN for all data registers. Re-enable Modbus and confirm with the Grid Guard Code.

Why do I receive error code 11 when polling the SHM 2.0?

Error code 11 indicates a unit ID mismatch. The SMA SHM 2.0 uses a unit ID separate from connected inverters, typically 3, but this can differ by installation. Check the unit ID assigned to the SHM in Sunny Portal's plant overview and update the value in your ModbusCloud portal template configuration to match.

Voltage and current readings look correct but reactive power values seem wrong.

Registers reactive_power_l1 through reactive_power_l3 use a signed int32 with a unit label of 'W' in this template, while the aggregate reactive_power register correctly reports in var. Cross-check the raw register value against the scaling applied in your portal; SMA 32-bit registers use big-endian word order (high word first).

The SHM stopped returning values after a firmware update.

SMA firmware updates can reset the Modbus TCP activation state. After any firmware upgrade, return to Sunny Portal and re-enable the Modbus interface under grid management services, re-entering the Grid Guard Code if prompted. Then confirm TCP connectivity on port 502 before resuming polling.

Free Modbus template: SMA SHM20

The SMA SHM 2.0 (Sunny Home Manager 2.0) is a home energy management gateway that sits at the grid connection point of PV installations and measures all power flows in real time. This Modbus TCP template reads per-phase voltages, currents, and frequency alongside per-phase and total active power for both grid consumption and grid export, plus reactive power across all three phases. Cumulative energy registers for consumption and production complete the picture, giving your ModbusCloud portal a full electrical portrait of the installation boundary. Installers gain immediate visibility into grid exchange without any additional metering hardware.

Name	Address	Function	Type	Unit	Access
voltage_l1 AC voltage on phase L1, in volts.	31253	FC03	uint32	V	R
voltage_l2 AC voltage on phase L2, in volts.	31255	FC03	uint32	V	R
voltage_l3 AC voltage on phase L3, in volts.	31257	FC03	uint32	V	R
reactive_power_l1 Reactive power on phase L1, signed integer in watts unit field.	31271	FC03	int32	W	R
reactive_power_l2 Reactive power on phase L2, signed integer in watts unit field.	31273	FC03	int32	W	R
reactive_power_l3 Reactive power on phase L3, signed integer in watts unit field.	31275	FC03	int32	W	R
reactive_power Total three-phase reactive power, in var, signed.	31277	FC03	int32	var	R
current_l1 AC current on phase L1, in amperes, signed.	31435	FC03	int32	A	R
current_l2 AC current on phase L2, in amperes, signed.	31437	FC03	int32	A	R
current_l3 AC current on phase L3, in amperes, signed.	31439	FC03	int32	A	R
frequency Grid frequency at the connection point, in hertz.	31447	FC03	uint32	Hz	R
active_consumption_energy Cumulative energy drawn from the grid, in watt-hours.	30581	FC03	uint32	Wh	R
active_production_energy Cumulative energy fed into the grid, in watt-hours.	30583	FC03	uint32	Wh	R
active_consumption_power Instantaneous total active power consumed from the grid, in watts.	30865	FC03	int32	W	R
active_production_power Instantaneous total active power exported to the grid, in watts.	30867	FC03	int32	W	R
active_production_power_l1 Active power exported to the grid on phase L1, in watts.	31259	FC03	uint32	W	R
active_production_power_l2 Active power exported to the grid on phase L2, in watts.	31261	FC03	uint32	W	R
active_production_power_l3 Active power exported to the grid on phase L3, in watts.	31263	FC03	uint32	W	R
active_consumption_power_l1 Active power drawn from the grid on phase L1, in watts.	31265	FC03	uint32	W	R
active_consumption_power_l2 Active power drawn from the grid on phase L2, in watts.	31267	FC03	uint32	W	R
active_consumption_power_l3 Active power drawn from the grid on phase L3, in watts.	31269	FC03	uint32	W	R