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SRNE ASP48120SH3 Modbus Register Map (validated)

Validated Modbus register map for the SRNE ASP48120SH3 three-phase hybrid inverter, verified register-by-register against the live Nansana unit (2026-07-27).

Bus: RS485, 9600 8N1, function code 03 (read holding registers), slave address 1. Source of truth (code): src/inverter/registers.py in nfe-modbus-energy-logger. Legend: VERIFIED = decoded value matched physical reality live. INFERRED = best-effort from live values. UNCONFIRMED = needs a different operating state (off-grid / heavy charge) to prove.

Valid register ranges (probed live)

  • P00 product info: 0x0000 to 0x0049
  • P01 battery / DC: 0x0100 to 0x0111
  • P02 inverter telemetry: 0x0200 to 0x023F (0x0240 and beyond return "Illegal data address")
  • P03 control commands: 0xDF00 to 0xDF09 (write-only, read back 0)
  • Settings E (writable params): 0xE001 to 0xE02D
  • Settings F: 0xF000 to 0xF01F

Live telemetry, full per-phase (P02) - VERIFIED

quantity phase A phase B phase C notes
grid voltage 0x0213 0x022A 0x022B x0.1 V
grid current 0x0214 (none) (none) x0.1 A. GRID CURRENT IS PHASE A ONLY in the documented map
grid frequency 0x0215 - - x0.01 Hz
inverter voltage 0x0216 0x022C 0x022D x0.1 V
inverter current 0x0217 0x022E 0x022F x0.1 A
inverter frequency 0x0218 - - x0.01 Hz
load current 0x0219 0x0230 0x0231 x0.1 A
load active power 0x021B 0x0232 0x0233 W. NO total register: sum the three phases
load reactive power (none) 0x0234 0x0235 var. REACTIVE IS B/C ONLY (phase A: derive)
load apparent power 0x021C (none) (none) VA. APPARENT IS PHASE A ONLY (B/C: derive S = sqrt(P^2 + Q^2))
load ratio 0x021F 0x0236 0x0237 %
load PF 0x021A - - reads 0 (unpopulated) - derive PF = P / S

Other P02: state 0x0210 (enum), password status 0x0211, bus V 0x0212 (x0.1) = PBus 0x0228 + NBus 0x0229, inverter DC component 0x021D (mV), mains charge current 0x021E (x0.1 A), heat-sink temps 0x0220/0x0221/0x0222 (x0.1 C, 0x0223 bogus), PV charge current 0x0224 (0, no PV), inverter fault 0x0226, charge status 0x0227.

Battery / DC (P01) - VERIFIED

SOC 0x0100 (%), battery V 0x0101 (x0.1 V), battery I 0x0102 (x0.1 A, signed, + charge / - discharge), device temp 0x0103 (reads 0, dead), DC load 0x0104-0x0106 (0), PV1 0x0107-0x0109 (0, no PV), charge state 0x010B (enum, mislabelled on this model), charge power 0x010E (W), PV2 0x010F-0x0111 (0).

Extended block 0x0238 to 0x023F - MODEL-SPECIFIC, NOT in the SRNE V1.7 doc

Discovered by probing (the V1.7 doc stops at 0x0237). Read live in mains/bypass:

addr live value INFERRED meaning status
0x0238 ~12 (1.2 A) per-phase current B (likely GRID current B) UNCONFIRMED (= load I B in bypass)
0x0239 ~13 (1.3 A) per-phase current C (likely GRID current C) UNCONFIRMED
0x023A ~1816 active power phase A INFERRED (matches load P_A)
0x023B ~267 active power phase B INFERRED (matches load P_B)
0x023C ~201 active power phase C INFERRED (matches load P_C)
0x023D ~2150 total or apparent (phase A ~2187 VA) UNCONFIRMED
0x023E ~297 unknown UNCONFIRMED
0x023F ~309 unknown UNCONFIRMED

IMPORTANT: in mains/bypass mode grid current = load current = (near) inverter current, so grid-side vs load-side registers are indistinguishable from this state. To confirm 0x0238/0x0239 as GRID current B/C (and the 0x023A-F meanings), re-read during an off-grid or heavy-charge state where grid, load and inverter differ. Community SRNE docs found online map 0x0230+ differently (e.g. "R-phase voltage") because they are for other SRNE models; they do NOT apply to this three-phase ASP unit.

Corrections vs the generic SRNE V1.7 doc (do NOT trust the generic enums)

  • Machine state 0x0210 = 2 means RUNNING (mains/bypass), NOT the generic "initialization". Only code 2 is verified.
  • Power factor 0x021A reads 0. Derive PF = active (0x021B) / apparent (0x021C).
  • Device temperature 0x0103 reads 0. Use heat-sink temps 0x0220 to 0x0222.
  • Charge-state enum 0x010B reads "1 = quick charge" even at 94% SOC with 0 W charge power, so the generic charge-state enum does NOT match this model either.

For the OpenEMS driver (important)

  • There is NO grid-power register, NO inverter-output-power register, NO ESS/battery AC-power register, and NO total-power register on this unit. The only power registers are LOAD power per phase.
  • Therefore the ESS SymmetricEss.ACTIVE_POWER must be DERIVED from battery DC power (0x0101 x 0x0102), the same V x I used for DcDischargePower. Do NOT map load power 0x021B to ACTIVE_POWER: 0x021B is what the loads consume (verified 1803 W while the battery was idle/charging ~16 W), and it is phase A only.
  • Consumption/backup meter active + reactive power per phase are available from the load registers (0x021B/0x0232/0x0233 active, 0x0234/0x0235 reactive) and can populate the ElectricityMeter power channels.

Writes

Both FC06 and FC16 are supported. Read-only registers reject with exception code 7. Settings 0xE0xx are writable. Control 0xDF00 area (power/reset/restore) is dangerous on the live unit: documented, not fired.