The gateway connects but registers 525 and 528 return no data. Why?

The most common cause is a Modbus unit ID mismatch. Confirm the slave address set on the inverter matches the unit ID in the ModbusCloud portal. ZCS Azzurro inverters ship with address 1 by default; daisy-chained units require unique sequential IDs.

Power and SOC values look correct for a moment then freeze. What now?

This often points to RS485 wiring issues: missing termination resistor, reversed A/B polarity, or long cable runs without shielding. Add a 120-ohm terminator at the far end of the bus, check that A(+) and B(-) are not swapped, and ensure the cable is not routed parallel to AC power wiring.

Register 525 returns a large positive value even when the battery is discharging. Is the scaling wrong?

Address 525 uses a signed int16 type, meaning discharge is represented as a negative value and charge as positive. If you see an unexpectedly large positive number during discharge, the reading tool may be interpreting the raw uint16 bits without applying the signed conversion. Confirm the template data type is set to int16.

The baud rate on my inverter was changed by a previous installer. How do I recover communication?

ZCS Azzurro hybrid inverters communicate at 9600 bps, 8 data bits, no parity, 1 stop bit by default. If communication fails, access the inverter's local display or web interface under the communication section, reset Modbus parameters to default, then update the ModbusCloud Gateway serial settings to match.

Free Modbus template: ZCS Azzurro Hybrid Inverter (battery)

The ZCS Azzurro Hybrid Inverter is a residential and light-commercial PV storage inverter that combines solar generation with battery management, balancing loads between the grid, PV strings, and a connected battery pack. This ModbusCloud template uses Modbus RTU over the inverter's RS485 COM port to read two core battery registers: instantaneous power at address 525 and state of charge at address 528. Knowing real-time charge and discharge power alongside available capacity lets installers and building owners track battery utilisation and detect abnormal cycling without opening a dedicated monitoring app.

Name	Address	Function	Type	Unit	Access
power Instantaneous battery power, signed: positive charge, negative discharge.	525	FC03	int16	W	R
soc Battery state of charge, 0 to 100 percent.	528	FC03	uint16	%	R

ZCS Azzurro Hybrid Inverter (battery)

Overview

Use cases

Installation

Things to watch for

Registers (2)

Working with Modbus in your projects?

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ZCS Azzurro Hybrid Inverter (pv)

ZCS Azzurro Inverter (battery)

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ZCS Azzurro Hybrid Inverter (grid)

ZCS Azzurro Inverter (pv)

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