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Firmware v2 overview

Firmware v2 is the current configurable firmware generation for the P1 Modbus Dongle.

Firmware v2 is a fundamental change from firmware v1. Instead of installing a separately compiled firmware variant for each application, v2 contains all supported Modbus mappings in one firmware image. Mapping, communication settings, monitoring and device control are handled at runtime through the Device Manager.

P1 Modbus Dongles shipped from 15 June 2026 use firmware v2.

Dongles currently running firmware v1 can be upgraded. Follow Migrate from v1 to v2 because the current mapping and communication settings must be recorded and restored after installation.

Fundamental difference

Firmware v1
Firmware v2

Separate firmware variant for each mapping or use case

One firmware image containing all mappings

Reflash to change to another mapping variant

Select another mapping in the Device Manager

Configuration mainly through Modbus registers and compiled defaults

Configuration and device control through the Device Manager

Basic status and update workflow

Live status, Modbus monitor and integrated updates

Main changes from v1

  • Selectable Modbus mappings in one firmware image

  • Configuration through the USB Device Manager

  • Live device, P1 and Modbus status

  • Persistent configuration stored on the dongle

  • Integrated stable firmware check and update flow

  • Modbus request monitor for diagnostics

  • Improved RGB status indications and hardware diagnostics

  • Support for P1 and, on compatible hardware, HAN as the smart meter source

Mappings included in firmware v2

The following mappings can be selected in the Device Manager without installing different firmware:

  • Default - TeltoCharge

  • Default - floats

  • SDM630

  • DTSU666

  • Alfen

  • EM330

  • EM111

  • ABB B21

  • EMPRO / MX3xx

  • KLEFR / Inepro

  • Phoenix Contact EEM / XM3xx

  • Charge Pro

  • DRIS

  • Wallbox - P1MB

  • SolarEdge

  • SunSpec 203

Default configuration

  • Mapping: Default P1 mapping

  • Modbus device ID: 43

  • RS485: 38400 8E1

  • Smart meter source: SMR (P1)

These values can be changed in the Device Manager. Changing a mapping does not require a firmware update.

Available mappings

Firmware v2 contains native mappings and emulations for integrations that expect a particular meter layout. See Firmware v2 register mappings for the complete list and register tables generated from the v2 recipes.

Updating

The preferred update method is the integrated updater in the Device Manager. See Updating firmware v2.

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