KACO blueplanet NX3 inverter
Register map(s) for this device, each at the trust rung it earned. Addresses are 0-based
as on the wire. Word order and scaling are confirmed at the hardware-verified rung and at no rung below it.
interop-verified
Read + decoded cleanly over a real network vs an independent third-party Modbus test server (transport and framing; reads are remapped into the server's register window, so the map's own addresses are NOT exercised). Does NOT prove word order/scaling against the actual device.
| point | address (0-based) | type | scale | unit |
|---|
| sunspec_id | 0 | U32BE | 1 | |
| common_block_did | 2 | U16 | 1 | |
| common_block_length | 3 | U16 | 1 | |
| device_address | 68 | U16 | 1 | |
| pad | 69 | U16 | 1 | |
link settings as documented (unverified): TCP/UDP; Supports Modbus-TCP and Modbus-UDP protocols.
bench facts as documented (unverified)
| identification notes | SunSpec ID at 40001 uniquely identifies the SunSpec Modbus Map. |
| power | String and battery inverter |
| doc revision | 3016547-03-250327 |
| firmware applicability | V5.0.2.4, V5.0.3.1, V5.0.3.3, V5.1.7.2, V5.1.9.0 |
field reports — community-sourced, unverified (checked 2026-06-11)
- Integration with SOLARWATT Manager flex and Energy Manager pro is broken on newer WiFi dongle firmware version 21618-015R (released August 31, 2023). Integration requires downgrading or maintaining firmware version 610-50057-12-15R.002 or 21618-011R. [source]
- Victron Venus OS (Cerbo GX) fails to discover the inverter via SunSpec Modbus TCP after installing a ripple control communication adapter (RCN-Kit) which forces a newer firmware update, even though the data remains readable by other integrations like Home Assistant. [source]
- The SunSpec Modbus implementation on the blueplanet NX3 only exposes PV generation data. Even if an external hardware energy meter is connected directly to the inverter, the grid meter data cannot be accessed via SunSpec Modbus. [source]
- confirmed: Supports Modbus-TCP and Modbus-UDP protocols — confirmed by the vendor document 'Modbus Protocol blueplanet 100-125 NX3' (revision 3016547-03-250327) which lists Modbus-TCP/UDP as supported protocols [1.1.1].
- confirmed: Document revision '3016547-03-250327' — confirmed by the footer of the official KACO Modbus Protocol document.
- confirmed: Firmware applicability 'V5.0.2.4, V5.0.3.1, V5.0.3.3, V5.1.7.2, V5.1.9.0' — confirmed by Table 1 ('Supported SW Version') in the vendor document.
- confirmed: SunSpec ID at 40001 uniquely identifies the SunSpec Modbus Map — confirmed by the vendor document stating the base register address is 40001 with sunspec_id at offset 0.
- confirmed: Power: String and battery inverter — confirmed by the vendor document's scope describing the MODBUS protocol of the 'KACO string and battery inverter series'.
- confirmed: Register map summary (sunspec_id @ 0, common_block_did @ 2, common_block_length @ 3, device_address @ 68, pad @ 69) — confirmed by the register mapping table in the vendor document where the Common Model starts at offset 2 (relative to base 40001) with DA (Device Address) at offset 66 of the block (absolute offset 68) and Pad at offset 67 of the block (absolute offset 69).
The trust ladder
Each rung states what it proved and what it did not. Gray until proven; green is earned by hardware only.
- generated — A prompt produced it. Unproven — anyone can regenerate this.
- structure-verified — Decode path is structurally sound (addresses, widths, finite values). Does NOT prove word order or scaling.
- interop-verified — Read + decoded cleanly over a real network vs an independent third-party Modbus test server (transport and framing; reads are remapped into the server's register window, so the map's own addresses are NOT exercised). Does NOT prove word order/scaling against the actual device.
- simulator-verified — Decoded correctly against a protocol emulator seeded with known-true values — catches word-order/scaling errors vs the emulator, not the physical device.
- hardware-verified x1 — Matched a real device with operator-attested readings as ground truth — the only rung that confirms word order + scaling on the wire.