Fronius Verto Plus 15–33.3

Commercial hybrid PV inverter

Six hybrid inverters from 15.0 to 33.3 kW share a local SunSpec Modbus TCP server for production monitoring. RS-485 meter channels and the battery link have different roles. Backup and dispatch need a commissioned control design.

Fronius Verto Plus hybrid PV inverter
  • Modbus TCP
  • Modbus RTU

Commercial hybrid PV inverter

Compatibility

Local SunSpec Modbus TCP monitoring

The July 2026 Verto Plus datasheet specifies Modbus TCP SunSpec on Ethernet, and the exact-family operating instructions define TCP Server, ports 502 or 1502, SunSpec float or integer/scale-factor models and the distinct Allow Control switch. A read-only Edge client can be qualified against the installed server and discovered model list.

Verto Plus 15.0, 17.5, 20.0, 25.0, 30.0 and 33.3 only, using installed firmware and country settings. Configure the inverter's TCP Server on a restricted site LAN; keep Allow Control off for read-only monitoring. Meter roles, RS-485 channel allocation, battery Modbus O and backup switchgear are separate. Do not use this guide to authorize writes or grid services.

Connect it with

The commissioned Plus inverter has TCP Server enabled and an approved site LAN route

  • Modbus
  • Edge
  • Platforms
Commercial hybrid PV inverter
Interface
Gateway
Edge
Output
Verto Plus 15–33.3Verto Plus SunSpec TCP server
Protected EthernetSegmented LAN
ZGW-20 GatewayHosts Edge locally
EpiSensor EdgeEdge Modbus TCP client
Customer platformMQTT · API · files
Modbus TCP
Protected Ethernet
Runs locally
Optional onward data
Select the inverter's configured port 502 or 1502 and float or int + SF SunSpec model type. Discover the actual models and check readings against the inverter interface. Leave Allow Control off. A separate feed-in-point meter is needed for grid import and export. The customer-platform output is optional; Edge remains the local system of record.

Models

Download
ModelsInterfaceRoute into Edge
Verto Plus 15.0 / 17.5 / 20.015, 17.5 or 20 kW rated AC; three MPPTs with two strings each; 28 A usable input and 50 A short-circuit limit per MPPT. Datasheet peak backup output is 30 kVA for up to 10 seconds with sufficient PV and battery power.Use the Plus TCP server and discovered SunSpec models; check the installed rating and battery before interpreting power or backup status.
Verto Plus 25.0 / 30.0 / 33.325, 29.99 or 33.3 kW rated AC in the July 2026 datasheet; the 30.0 label is a power class, not a 30,000 W guaranteed rating. Three MPPTs; peak backup output is 50 kVA for up to 10 seconds under stated conditions.Check the exact nameplate and country setup, then discover the TCP SunSpec profile. Do not reuse limits from the non-Plus Verto 30.0.

Specifications

The six Plus variants span 15.0 to 33.3 kW, with three MPPTs and two PV strings per tracker, 150–870 V usable MPP range and 1000 V maximum DC input. The July 2026 datasheet specifies a 150–700 V battery input, IP66 enclosure, 865 × 574 × 279 mm and 43 kg. The country-specific nameplate remains authoritative for grid connection and backup design.123

Exact variants
Verto Plus 15.0, 17.5, 20.0, 25.0, 30.0 and 33.323
PV input
Three MPPTs, two strings each; 28 A usable / 50 A short-circuit per MPPT; 150–870 V MPP; 1000 V maximum DC2
Rated AC power
15, 17.5, 20, 25, 29.99 and 33.3 kW respectively in the July 2026 sheet2
Battery side
One 150–700 V input; approved Fronius Reserva/Reserva Pro and listed BYD Battery-Box variants, subject to datasheet exclusions12
Local TCP
RJ45 LAN 10/100 Mbit; SunSpec TCP server on configured port 502 or 1502; float or int + SF model type12
RS-485
Two two-wire Modbus RTU SunSpec channels, also used for Fronius Smart Meter and system components12
Battery communications
Separate Modbus O / RJ45 / 12 V battery connection on Plus devices1
Full Backup
Battery and external grid switching required; about 11 s switchover; temporary 30 kVA or 50 kVA boost by class under datasheet conditions123
Enclosure
IP66; 865 × 574 × 279 mm; 43 kg; active cooling2

Interface

Documented measurements and integration boundaries for Verto Plus 15–33.3.

  • Ethernet is an RJ45 10/100 Mbit connection; the datasheet names Modbus TCP SunSpec and JSON. The manual offers TCP ports 502 or 1502 and float or int + SF SunSpec inverter model choices. Site settings and the discovered model list determine the actual reader configuration.
  • Modbus 0 and Modbus 1 are two separate two-wire RS-485 channels. The manual's RTU Server setting selects M0 or M1, address, baud rate and parity; Fronius meters and other system components may already occupy those channels. Do not treat a meter configuration as a free Edge bus.
  • The Plus battery connection is a separate Modbus O/RJ45/12 V interface for approved storage. Its RJ45 connector does not make it an Ethernet or Edge input. Battery charge limits depend on the paired battery and installed firmware.
  • The manual states that Modbus TCP/IP is unsecured. Restrict its network reach and do not forward the server port to the Internet. Allow Control enables on/off, power reduction, reactive settings and battery control; read-only monitoring leaves it off.
  • Full Backup requires a battery and external grid switching equipment. Datasheet switching time is approximately 11 seconds, so it is not an uninterruptible power supply. Peak boost figures last at most 10 seconds with sufficient PV and battery power.
  • A Fronius primary meter at the feed-in point supplies site export and import context. Inverter production alone cannot prove net export or a flexibility dispatch outcome. Multiple Inverter Control and its priorities are a separate, commissioned Fronius plant function.

Assessment

Six Verto Plus 15.0–33.3 variants using the commissioned local SunSpec TCP server; meter, battery, backup and dispatch functions separate.

InteroperabilitySupported with conditions
The exact-family manual and sheet document a local SunSpec TCP server, two selectable ports and model representations; commissioned settings and model discovery remain necessary.12
AccuracySupported with conditions
SunSpec inverter readings support production monitoring; feed-in-point import and export need a separate meter and acceptance check.12
SecurityLimited
Fronius calls Modbus TCP/IP unsecured. Restrict the LAN and keep Allow Control disabled for a reader.1
ReliabilityNot yet assessed
The retained documents do not establish site availability, stale-data thresholds or backfill to Edge.1
RuggednessSupported with conditions
The datasheet specifies IP66, active cooling and an indoor/outdoor mounting range; maintain the specified clearances and installation orientation.2
ScalabilityLimited
Each commissioned TCP endpoint needs its own discovered model set. Fronius Multiple Inverter Control has separate client/priority rules that an added reader must not disrupt.1
LifecycleNot yet assessed
No guaranteed firmware support or replacement period is established by the retained product, datasheet and manual captures.123

Setup

Discover the SunSpec model, then read power

Start with the configured local TCP server and its inverter unit ID. The reads below use FC03; the returned SunSpec model determines the measurement layout. Byte values and the example model position are synthetic.

Connection
Use the inverter LAN address and configured TCP port 502 or 1502. Read the inverter identity, not the meter at its default unit ID 200. Leave Allow Control off.
Signature read
FC03 at wire address 40000, quantity 2: PDU 03 9C 40 00 02. Expected SunSpec signature bytes 53 75 6E 53 spell SunS. If absent, check endpoint and unit ID before selecting points; the standard also permits bases 0 and 50000.
Common model discovery
Read the two-register header after the signature. Synthetic bytes 00 01 00 42 indicate common model 1 and 66 following registers. With its header at wire 40002, the next header is 40002 + 2 + 66 = 40070. Compare manufacturer, model and serial number in the common model.
Select the returned model
Only use the power calculation below if the returned header identifies model 103, the three-phase int + SF model. Models 113, 203 or 213 have different definitions; use their own layout without changing the representation another client uses.
Conditional model-103 power read
Let H be the discovered model-103 header address. W is at H + 14 and W_SF at H + 15, each signed 16-bit. FC03 quantity 2 reads both. If H = 40070, the wire address is 40084 (0x9C94), PDU 03 9C 94 00 02. H = 40070 is an example, not a fixed Verto address.
Synthetic decode
Bytes 30 39 FF FF decode to W = 12345 and W_SF = -1. Calculate 12345 × 10^-1 = 1234.5 W. Decode the scale factor as signed; do not treat this pair as Float32. A signed value 0x8000 is unavailable, not zero power.
Next monitoring points
For returned model 103, frequency is at H + 16 with its signed scale factor at H + 17. Keep inverter production separate from the site meter’s import/export reading.

Acceptance: Compare a fresh decoded power value with the inverter interface before adding points. This is a public-documentation starting point and synthetic decoder example, not a physical Verto test or a control procedure.

  1. Identify the inverter

    Check the model label and firmware against the July 2026 Plus sheet, especially the 29.99 kW Verto Plus 30.0 rating.

  2. Record the TCP settings

    Confirm the TCP Server port and SunSpec representation; leave Allow Control off for the first read-only trial.

  3. Preserve the network boundary

    Keep Modbus 0/1 meter, RTU, battery and multiple-inverter wiring assignments as commissioned.

  4. Compare the first reads

    Discover the SunSpec signature, common identity and model headers as shown below. For returned model 103, read W and W_SF at header offsets 14 and 15 and compare decoded power with the inverter interface.

  5. Keep system roles separate

    If backup is installed, verify battery, external grid switch and approximately 11-second transfer with the responsible electrical designer.

Common questions

Can Edge monitor a Verto Plus locally without Fronius Solar.web?
Yes, for a commissioned local read-only path. Fronius documents a SunSpec Modbus TCP server on the inverter's Ethernet connection. Enable the server on the approved LAN, select its configured port and model type, and validate the discovered values; cloud registration is a separate function.12
Is the battery RJ45 port an Ethernet port for Edge?
No. Fronius labels that separate Plus-only connector Modbus O, RJ45 and 12 V battery power. Use the LAN port for the documented TCP server, and leave battery wiring to the approved storage design.12
Does the two-port RS-485 specification mean a free third-party bus?
No. Modbus 0 and Modbus 1 can be assigned to Fronius meters or system components, and the manual describes distinct RTU Server settings. Check installed terminal ownership before any added device; the read path in this guide uses TCP.12
Can a Verto Plus provide uninterrupted backup or VPP dispatch from this guide?
Full Backup needs a battery and external grid switch, with about 11 seconds of transfer in the datasheet. The local Modbus menu offers an Allow Control switch, but writing commands requires a separately approved site control and fail-safe design. No dispatch or UPS behavior is implied by read-only monitoring.123

Sources

  1. Fronius Verto Plus 15–33.3 kW operating instructions (opens in a new tab) Fronius
  2. Fronius Verto Plus datasheet EN V07 July 2026 (opens in a new tab) (PDF) Fronius
  3. Fronius Verto and Verto Plus product page (opens in a new tab) Fronius
  4. SunSpec Device Information Model Specification 1.1 (opens in a new tab) (PDF) SunSpec Alliance
  5. SunSpec three-phase inverter model 103 definition (opens in a new tab) SunSpec Alliance

Further reading

Product names and trademarks belong to their owners. Publication does not imply endorsement or a commercial relationship.