Why does the power register always read zero?

Register 30005 reflects data collected from a grid sensor at the grid-to-system checkpoint. If no grid sensor or gateway meter is connected and configured in the Sigenergy system, the value will remain zero. Verify that the grid sensor shows as connected (register 30004 = 1) in the mySigen app before troubleshooting Modbus.

The Gateway connects but no register values appear. What now?

Plant-level registers, including all grid sensor registers, are only accessible at slave address 247. If you set any other unit ID in the portal, reads will fail silently. Also confirm the Modbus TCP Server Enable switch is active in the SigenStor Settings panel and that no firewall is blocking port 502.

Phase current registers return garbage or implausible values. Why?

The currents registers use an int32 type spanning two consecutive holding registers each. If your polling client reads only one register word instead of two, the result will be corrupted. Ensure the ModbusCloud template is using the correct int32 (2-register) read for addresses 31017, 31019, and 31021.

The energy register value looks far too large. Is the scaling wrong?

The energy register at address 30562 is a uint64 spanning four register words. Confirm your gateway is reading all four consecutive registers and applying any scaling factor documented in the Sigenergy Modbus protocol for the firmware version installed. Misreading fewer words produces an overflowed or meaningless figure.

Free Modbus template: Sigenergy SigenStore EC (grid)

The Sigenergy SigenStore EC is a modular hybrid energy storage system combining a hybrid inverter, battery power conversion, and integrated energy management. Compatible with the Sigen Hybrid and Sigen PV Max, it connects to residential and small-commercial grids. This Modbus TCP template reads the grid connection point over function code 3, covering active power at the meter boundary, cumulative energy throughput, and per-phase currents on phases A, B, and C. The ModbusCloud Gateway polls slave address 247 on port 502, giving installers a live, per-phase view of import and export without manual data collection.

Name	Address	Function	Type	Unit	Access
power Grid active power; positive = import, negative = export.	30005	FC03	int32	W	R
energy Cumulative energy exchanged at the grid connection point.	30562	FC03	uint64	Wh	R
currents_a AC current on grid phase A.	31017	FC03	int32	A	R
currents_b AC current on grid phase B.	31019	FC03	int32	A	R
currents_c AC current on grid phase C.	31021	FC03	int32	A	R

Sigenergy SigenStore EC (grid)

Overview

Use cases

Installation

Things to watch for

Registers (5)

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