Overview

KOSTAL PLENTICORE plus (3-10 kW) and PLENTICORE BI (hybrid with battery) use Modbus TCP on port 1502 with unit ID 71 — both non-standard values specific to KOSTAL. Confirm in inverter web interface: Settings > Communication > Modbus TCP.

SunSpec Register Map

SunSpec Model 103 registers: 40071 (AC power total, int16, W), 40083 (DC power total, int16, W), 40094 (daily yield, uint32, 0.001 kWh — register value x 0.001 kWh).

KOSTAL SMART ENERGY METER

KOSTAL SMART ENERGY METER (SEM): connected to PLENTICORE via RS485 internally; accessible via same Modbus TCP connection on unit ID 200. SEM key register: 40191 (grid power, int32, W — positive=import from grid, negative=export to grid). This is the essential register for self-consumption logic.

Weinzierl KNX Modbus TCP Gateway

Device entry 1 (IP:port 1502, unit 71) with read tasks for AC power (reg 40071) and daily energy (reg 40094). Device entry 2 (same IP:port 1502, unit 200) for SEM grid power (reg 40191). Map AC power to KNX GA 6/0/1 DPT 9.001 (kW). Grid power to GA 6/0/2 DPT 9.001 signed.

PLENTICORE BI Battery Registers

Additional registers on unit 71: 40255 (battery SOC, uint16, %) mapped to KNX DPT 5.001. 40258-40259 (battery power, int32, W, positive=charging) mapped to KNX DPT 9.001. 40261 (battery voltage, uint16, 0.1V).

KNX Self-Consumption Logic

When GA 6/0/2 (grid export) < -1500W — activate SG Ready state 3 (heat pump boost via MDT relay GA 7/0/1). When < -3500W — additionally write Alfen EV charger current increase.

SG Ready and Forced Battery Charge

SG Ready on PLENTICORE BI: digital input terminals DI1/DI2 on PLENTICORE BI control board accept SG Ready state signals. KNX MDT AKD relay channel 1 drives DI1, channel 2 drives DI2. When Tibber tariff = CHEAP — KNX writes relay state SG state 4 (both relays on) — PLENTICORE BI forced battery charge.

Feed-In Limitation

PLENTICORE has 70% feed-in limitation option (German law for systems registered after 2012). Enable in inverter settings. KNX monitoring: track daily export energy from SEM and alert if export exceeds 30% of daily generation (indicates optimisation opportunity).