ABB TRIO-20.0/27.6-TL-OUTD string 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
inverter_global_state	123	U16	1	Decimal
inverter_state	124	U16	1	Decimal
inverter_dcdc_channel_1_state	125	U16	1	Decimal
inverter_dcdc_channel_2_state	126	U16	1	Decimal
inverter_alarm_state	127	U16	1	Decimal
inverter_daily_energy	131	F32BE	1	Wh
inverter_total_energy	133	F32BE	1	kWh
inverter_partial_energy	135	F32BE	1	kWh
inverter_week_energy	137	F32BE	1	kWh
inverter_monthly_energy	139	F32BE	1	kWh
inverter_yearly_energy	141	F32BE	1	kWh
inverter_grid_voltage	143	F32BE	1	V
inverter_grid_current	145	F32BE	1	A
inverter_grid_power	147	F32BE	1	W
inverter_frequency	149	F32BE	1	Hz
inverter_input_1_power	151	F32BE	1	W
inverter_input_1_voltage	153	F32BE	1	V
inverter_input_1_current	155	F32BE	1	A
inverter_input_2_power	157	F32BE	1	W
inverter_input_2_voltage	159	F32BE	1	V
inverter_input_2_current	161	F32BE	1	A
inverter_temperature	163	F32BE	1	°C
inverter_booster_temperature	165	F32BE	1	°C
inverter_isolation_resistance	167	F32BE	1	MΩ
inverter_cos_phi	171	F32BE	1	N/A
heartbeat_counter	299	U16	1	Decimal
inverter_grid_reactive_power_holding	300	F32BE	1	VAR
inverter_grid_voltage_holding	302	F32BE	1	V
inverter_grid_power_holding	304	F32BE	1	W
inverter_grid_current_holding	306	F32BE	1	A

link settings as documented (unverified): RTU; default 19200 8N1; FC 03,04,06,16; Interface: RS-485 (half duplex). Start bit: 1, Stop bit: 1, Parity: No parity, Data bits: 8. Default baud rate is 9600 on USA and Japan versions, and 19200 on Europe versions.

bench facts as documented (unverified)

terminals	RS-485 serial line
broadcast	supported
model register	115
serial register	103
identification notes	Model identifier register is 115 (0-based). Serial number registers are 103 to 108 (0-based).
doc revision	1.6
firmware applicability	Minimum Inverter Update Version: 1542C for Europe version; 1542D for USA and Japan version

field reports — community-sourced, unverified (checked 2026-06-11)

The inverter uses Word Swapped Floating Point 32-bit (SF32) data types where the two Modbus registers must be swapped before processing the IEEE754 floating point value. [source]
When the inverter enters standby/night mode due to low solar input voltage, Modbus RTU communication may be suspended or respond with errors, causing communication timeouts on the PLC/master side. [source]
Modbus data registers are documented as 1-based addresses in some vendor materials, requiring an offset of -1 (0-based addressing) in the Modbus PDU request (e.g., register 301 is requested as 0x012C / 300). [source]
confirmed: Baud rates [2400, 4800, 9600, 19200, 38400, 57600, 115200] with default 19200 on Europe versions and 9600 on USA/Japan versions — confirmed by Modbus RTU Register Map For TRIO-20.0 (27.6) - TL-OUTD Revision 1.6
confirmed: Minimum Inverter Update Version: 1542C for Europe version; 1542D for USA and Japan version — confirmed by Modbus RTU Register Map For TRIO-20.0 (27.6) - TL-OUTD Revision 1.6
confirmed: Model identifier register is 115 and serial number registers are 103 to 108 (0-based) — confirmed by Modbus RTU Register Map For TRIO-20.0 (27.6) - TL-OUTD Revision 1.6
confirmed: Broadcast mode is supported for write single (06) and write multiple (16) registers — confirmed by Modbus RTU Register Map For TRIO-20.0 (27.6) - TL-OUTD Revision 1.6

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.

If your device isn't here, upload its register map. Generation is free, and the connector keeps the rung it earns under testing.

To prove a connector against your own device, order hardware verification. If it doesn't verify, you don't pay.

Platform builders can license the verified library: machine-readable maps, the firmware matrix, API access.