Overview

Alfen Eve Single Pro-line 22 kW (three-phase, IP54) is the most common commercial EV charger in the Netherlands and increasingly deployed across Europe. Modbus TCP on port 502, unit ID 1. Registers use float32 (2 x 16-bit, big-endian).

Key Registers

Register pairs: 300-301 (charge state: 0.0=A, 1.0=B1, 2.0=B2, 3.0=C1/charging, 4.0=C2, 5.0=D), 316-317 (charge current setpoint, A, write), 320-321 (actual charge current L1, A), 344-345 (active power total, W), 374-375 (session energy, Wh).

MDT Modbus Gateway Configuration

Configure Alfen Eve at IP 192.168.1.100, port 502, unit 1. Read task 1: regs 344-345 (float32, 2 regs) every 10s mapped to KNX GA DPT 9.001 (kW). Read task 2: regs 300-301 (float32) every 10s mapped to KNX DPT 5.010 (charge state). Write object: regs 316-317 (float32, 2 regs) from KNX float GA.

Dynamic Load Management

Eastron SDM630 Modbus TCP (separate gateway read task): active power total (float32, regs 52-53) mapped to KNX GA 6/0/2 (house consumption W). KNX logic block calculates: 'available_current = (contract_limit_A x 230 - house_consumption) / 230'. Clamp to range 6-32A. If 'available_current < 6': write 0.0 to Alfen regs 316-317 (pause charging). Update every 30s.

Multiple Chargers

Multiple chargers: Alfen SCU (Smart Charging Unit) manages up to 100 Eve chargers internally with load balancing — KNX only needs to communicate with SCU Modbus master at single IP address. For 2-4 chargers without SCU: each Eve has separate IP; MDT gateway handles up to 8 TCP connections.

Alfen ACE Energy Storage Integration

Alfen ACE energy storage: Modbus TCP registers 500-501 (battery SOC, float32, %) and 504-505 (battery power, float32, W). Same gateway, separate read tasks. KNX SOC monitoring: when ACE SOC < 20% — disable forced charge from tariff automation.

Commissioning Verification

Use Modbus Poll (freeware) to verify register 300-301 returns 3.0 when a car is actively charging. Confirm register 344-345 matches charger display power reading.