All registers return zero or timeout immediately after connection. Why?

The StoraXe Master Controller Modbus TCP service only responds on the front-side Ethernet port. If you connected to a rear or secondary port, no Modbus traffic will pass. Confirm the cable is on the correct port and that the controller IP address entered in the ModbusCloud portal matches the actual network address of that interface.

The active_power register reads a large unexpected negative number. Is this wrong?

No. The StoraXe uses a signed convention where negative active power means the battery is charging and power is flowing from the grid into the system. A large negative value during daytime often indicates a forced-charge schedule or a state transition. Cross-check the grid_mode register to confirm the current operating mode.

Cell voltage registers (min and max) always read zero after upgrading firmware.

The min_cell_voltage and max_cell_voltage registers were added in a later revision of the Master Interface specification. If the SRC1xxx controller is running firmware older than the version that introduced these registers, addresses 137 and 138 will return zero. Update the controller firmware to a version that supports the extended register set.

How recent does the firmware need to be for all registers to work?

The Master Interface specification covering this register map is valid for SRC1xxx firmware 2.0.4 and higher. Installations running older firmware may return zeros or errors on registers added in later revisions. Check the firmware version in the controller web interface and apply the relevant update from the Adstec support portal before commissioning.

Free Modbus template: Adstec StoraXe

Name: Adstec StoraXe
Brand: Adstec
SKU: b3b2799d-5ea0-4d59-b029-556924424d9a

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Free Modbus template: Adstec StoraXe | ModbusCloud

Registers (9)

9 read / 0 write

Name	Address	Function	Type	Unit	Access
grid_mode Current operating mode: grid-tied, island, or standby.	0	FC04	uint16		R
active_power AC active power at the grid connection; negative indicates charging.	1	FC04	int16	W	R
reactive_power AC reactive power at the grid connection, in var.	2	FC04	int16	var	R
max_apparent_power Maximum apparent power the inverter can deliver, in W.	124	FC04	uint16	W	R
soc Battery state of charge, 0 to 100 percent.	125	FC04	uint16	%	R
active_discharge_energy Cumulative energy discharged from the battery, in Wh.	133	FC04	uint32	Wh	R
active_charge_energy Cumulative energy charged into the battery, in Wh.	135	FC04	uint32	Wh	R
min_cell_voltage Lowest individual cell voltage across all modules, in mV.	137	FC04	uint16	mV	R
max_cell_voltage Highest individual cell voltage across all modules, in mV.	138	FC04	uint16	mV	R