Installation · SolaX

Install GridZeno on SolaX X3-PRO.

X3-PRO G2 is a three-phase grid-tied inverter without a battery, so GridZeno can show the production and, where the protocol allows it, limit the export. There's no battery to control. The dongle is connected with two wires in the 6-pin RS485 terminal block, terminals a and b. The energy meter has its own terminals, e and f.

Applies to: X3-PRO 8-30K-G2
Connection: Wires in the inverter's terminal plug
Time: About 30 minutes

A grid inverter without a battery. GridZeno shows what it produces but can't control anything on it. What GridZeno can do on SolaX X3-PRO

How the dongle recognises it: The serial number in holding 0x300 starts with MP156T or MPT: X3-PRO G2.

GridZeno Dongle for SolaX X3-PRO

What you need

GridZeno Dongle: The device ID is on the label, e.g. GZ-A1B2C3.
Cable: GridZeno's Modbus cable with one end cut off, or another network cable with one plug.
Screwdrivers and wire stripper: For the cover's M4 screws and the terminal block's small M2 screws.
USB power: A 5 V USB charger and a cable with USB-C.

The port

On the underside of the inverter, under a cover next to the COM port. The cable is passed in through a nut with a plug.

Port: RS485 terminal (6-pin terminal block)

The RS485 terminal block. SolaX calls the terminals a to f from the left, drawn here as 1 to 6. a and c are connected, and so are b and d. The numbers are on the plug.

Pin 1 A, a, 485A
Pin 2 B, b, 485B

The cable

A network cable with an RJ45 plug for the dongle at one end and the other end cut off. At the inverter end, only the two wires from pins 4 and 5 are used. The terminal block has no RS485 GND, so the white/green wire isn't used.

From the dongle to the inverter
Dongle end	Inverter end
Dongle pin 4, blue (A)	RS485 pin 1 (terminal a), 485A
Dongle pin 5, white/blue (B)	RS485 pin 2 (terminal b), 485B
The other wires	Cut off and insulated

Settings

On the inverter

Settings > RS485 CommAddr: 1, as set at the factory. Settings requires the installer code, which is 2014 from the factory.
Settings > Modbus Function > Function Select: COM485, not Ev Charger.

In GridZeno's Welcome

The inverter is chosen in GridZeno: in Welcome the first time, and later under System, Change inverter. The dongle fetches its setup from there.

Manufacturer and model: SolaX, X3-PRO
Connection: By cable (RS485)
RS485 settings: Address 1 and 8N1. SolaX doesn't mention the baud rate in the manual: start with 9600, and try 19200 if the dongle gets no answer.

Step by step

Each step has a small drawing that shows what to do.

1
Check the address
In the display, go to Settings, and type the installer code. Under RS485 CommAddr the address must be 1, as set at the factory. Under Modbus Function, Function Select must be set to COM485.
2
Open the cover over RS485
Switch the inverter off. Unscrew the cover over the RS485 terminals, loosen the nut, and take the plug out.
3
Pass the cable through the nut
Pass the cut end of the cable through the nut and in to the terminal block.
4
Prepare the cable
Strip 6 to 7 mm from the two wires from pin 4 (blue) and pin 5 (white/blue). Insulate the other wires.
5
Put the wires in terminals a and b
Blue (A) goes in terminal a and white/blue (B) in terminal b. Tighten the small screws. Don't touch wires in e and f: they belong to the energy meter.
6
Close the cover again
Fit the terminal block in the inverter, screw the cover on, and tighten the nut by hand.
7
Plug the RJ45 end into the dongle
The cable's other end goes into the dongle's RS485 port. Place the dongle somewhere dry and close to the inverter, so the cable doesn't hang from the plug.
8
Connect power to the dongle
Plug the USB-C cable into the dongle and the charger into a socket. The dongle starts by itself. It gets power from the charger, not from the inverter.
9
Connect the dongle to the network
Over Wi-Fi: the first time, the dongle creates its own Wi-Fi, GridZeno-Setup- followed by the last characters of the device ID. Connect your phone to it, choose your own network, enter the password, and press Save and connect. When it says Connection OK, press Go to GridZeno. Over cable (LAN): plug a network cable from the router into the dongle's network port.
10
Log in, and choose your inverter
Log in to GridZeno. Welcome pairs the dongle with its device ID. Then choose your inverter, SolaX X3-PRO, and the connection By cable (RS485). Press Save inverter, and the dongle fetches its setup and reads the inverter. If the dongle gets no answer, swap the two wires in a and b. If that doesn't help, go to System, press Change inverter, and set the baud rate to 19200 under RS485 settings.

The dongle's own setup is described with screenshots in The user guide, and the pairing in Getting started.

Take care

Use terminals a and b, or c and d. Terminals e and f are the energy meter's. DataHub, Adapter Box G2 and the EV charger also use a to d, so if there are already wires in them, write to us before you connect the dongle.

The COM port next to it's an RJ45 port for DRM, remote stop and heat pump control, and pin 1 carries 13 V. The dongle doesn't go in it.

SolaX writes that A and B must be crossed towards a computer, but not towards other devices. If the dongle gets no answer, swap the two wires in a and b.

If you aren't used to fitting wires in a terminal connector, let the installer do it.

What GridZeno can control on SolaX X3-PRO, and how, is on the page about SolaX X3-PRO. If you're stuck, write to us with the model name.

Source

Ports, pins and menus are from the manufacturer's own manual: SolaX X3-PRO G2 8-30 kW User Manual, Version 14.0 (2026-01-12), Sections 8.5.1, COM Communication Connection (table 8-4), 8.5.2, RS485 Communication Connection (table 8-5), and 10.4, Detailed Operation of Settings.