KOSTAL PLENTICORE G3

Compatibility

Compatible with EpiSensor Edge over Modbus TCP

KOSTAL's interface description revision 2.9 documents a Modbus TCP server on the inverter's Ethernet port, with FC03 holding registers for PV, battery, grid and energy-meter values and a SunSpec model chain. Edge reads it as a Modbus TCP client on the site network.

PLENTICORE G3 S, M and L (4.0 to 20 kW), using KOSTAL interface description revision 2.9 of 17 July 2026, valid from G3 software 3.07.00. Site check: read the product name and SoC at the start of commissioning and compare them with the inverter's web server. Read-only monitoring; KOSTAL's power, battery and MDC control registers stay with the site's energy manager.

Connect it with

• Gateway ZGW-20 From €899 ex VAT Configure
• Evaluation Gateway on a Raspberry Pi Edge with one device licensed Free Set up

Models

Specifications

The G3 comes in three basic power classes, S 4.0 kW, M 8.5 kW and L 15 kW, each with two optional paid power upgrades up to 7.0, 12.5 and 20 kW. It has three MPP trackers; DC3 can be released as a battery input for KOSTAL-approved high-voltage batteries.^2, 3

Power classes

S 4.0 / 5.5 / 7.0 kW, M 8.5 / 10 / 12.5 kW, L 15 / 17.5 / 20 kW rated AC power²

Grid connection

3N~, 230/400 V, 50 Hz²

Battery input

DC3, optional; 95 to 820 V working voltage²

Modbus TCP defaults

TCP port 1502, unit ID 71 (unit ID changeable)¹

Function codes

FC03 read 1 to 125 registers; FC06 and FC16 are writes¹

Byte order

Little-endian CDAB (default) or big-endian ABCD SunSpec¹

SunSpec models

1, 103, 113, 120, 123, 160, 203 and 802, ending with 65535¹

Environment

IP65; -20 to 60 °C; up to 2000 m²

Interface

Documented measurements and integration boundaries for PLENTICORE G3.

• Identity, FC03: product name at register 768 (hex 0300, String, 32 registers), power class at 800 (0x0320, String, 32), article number at 6 (String, 8), serial number at 14 (String, 8) and inverter state at 56 (0x0038, U32: 6 is FeedIn, 10 Standby, 15 Shutdown).
• Inverter AC, Float in two registers: total AC active power at 172 (0x00AC) in W, voltage phase 1 at 158 in V, grid frequency at 152 in Hz, and total DC power at 100 (0x0064) in W.
• Battery, Float: state of charge at 210 (0x00D2) in %, battery voltage at 216 in V, battery temperature at 214 in °C and battery charge (-) / discharge (+) current at 200 (0x00C8) in A. A U16 copy of SoC sits at 514 (0x0202) and actual battery charge/discharge power at 582 (0x0246) is S16 in W.
• Battery energy, Float in Wh: total DC charge energy at 1046 (0x0416), total DC discharge energy at 1048, total AC charge energy grid to battery at 1054 and battery work capacity at 1068. State of health at 40428 (0x9DEC) is U16 in %, only where the battery reports it.
• Connected energy meter, Float: total active power at 252 (0x00FC) in W. With the sensor at the grid connection (position 2), positive is power drawn from the grid and negative is feed-in; at home consumption (position 1), positive is house consumption.
• PV and yield, Float: DC1 power at 260, DC2 at 270, DC3 at 280 in W; total yield at 320 (0x0140) in Wh. Home consumption from PV, battery and grid is at 116, 106 and 108 in W.
• MDC plants from G3 software 3.06.10, read on the host inverter: plant SoC at 1547 (0x060B) and plant total battery power at 1549 (negative is charging), both Float.
• Word order: Float, U32 and S32 values span two registers. The default byte order is little-endian (CDAB), so the second register holds the high half; register 5 reads 0 for CDAB and 1 for big-endian (ABCD) SunSpec mode.
• Control registers exist: active and reactive power setpoints (533, 583, 585, 832), external battery management (1024 to 1044), battery limitation (1280 to 1288) and MDC plant control (1557 to 1573). Edge does not write them; control needs the site owner's and KOSTAL's agreement and is outside this guide.

Setup

1. Identify the inverter and its software

   Record the nameplate power class, the software version shown in the web server and the connected battery. This guide uses KOSTAL interface description revision 2.9 of 17 July 2026, valid from G3 software 3.07.00. Registers added in later software carry a footnote with the version they need, such as the battery limitation block from G3 software 03.05.

2. Enable Modbus and set the byte order

   Enable Modbus in the inverter web server under Settings > Modbus / Sunspec (TCP). The same page sets the byte order: little-endian (CDAB) is the default, big-endian (ABCD) is the SunSpec setting. Note which one the site uses, because every Float read depends on it. Changing it can break another client already reading the inverter.

3. Connect Edge

   Create a Modbus TCP connection in Edge to the inverter's IP address, port 1502 and unit ID 71. Use FC03 for every read. KOSTAL advises a polling cycle longer than 1 second, so poll at 5 to 10 seconds for monitoring.

4. Read identity, then SoC

   Confirm the product name at 768 and the power class at 800, both ASCII strings of 32 registers, with a commissioning Modbus tool. Then add SoC at 210 to Edge as a two-register Float, as in the worked check. Send the table hex address as the start address: SoC is 0x00D2. Decode CDAB by putting the second register first, and compare the result with the SoC on the inverter web server.

5. Add battery, meter and PV points

   Add battery voltage 216, current 200 and power 582, meter power 252, AC power 172 and DC power 100. Record the energy meter's sensor position, because it decides what the sign of register 252 means. Read each Float as one two-register request so the halves come from the same sample, and keep a failed poll stale rather than zero.