Does AC Coupling Total Active Power only report when off-grid? (S6-EH1P-8K-L-PLUS reads 0 while grid-connected, despite real generation)

[IamMattM]

Setup:

Inverter: Solis S6-EH1P-8K-L-PLUS, AC-coupled PV (no DC strings)
Integration: solis_modbus v4.1.5
Model option: S6-EH1P, connection: S2_WL_ST, via ESPHome Modbus TCP bridge
has_ac_coupling: true

I'm seeing AC Coupling Total Active Power and the related daily/monthly/yearly generation sensors report 0 continuously — even during strong solar generation. At the same moment, SolisCloud's flow diagram shows real AC-coupled output (2.704 kW live, 12.61 kWh daily yield).

Debug logs confirm this isn't a decode/scaling issue — the integration is correctly polling the right registers and getting a genuine raw 0, 0 back from the inverter:

Group 34496 starting for (192.168.1.180.1)
Read Input Registers: register = 34496, count = 2
block 34496, register 34496 has value 0
block 34496, register 34497 has value 0

Other sensor groups (battery, grid, AC voltage/current) read correctly via the same connection at the same time, so it's isolated to this register group, not a general Modbus connectivity issue.

Looking at Solis's own support documentation on the "AC Coupling" smart-port feature (SolisCloud Remote Control Settings guide), it describes this as an off-grid management function — managing AC-coupled PV inverters specifically when grid and generator are both disconnected, e.g. via frequency-shifting control to throttle PV as battery SOC rises. My system is grid-connected, so if registers 34496/34497 are tied to that off-grid control feature rather than general AC-coupled PV metering, a 0 reading while grid-connected would actually be expected behavior, not a bug.

Question: Is there a different register/sensor in this integration that reports general AC-coupled PV power output while grid-connected (SmartMeter2 , PV inverter , ID:002 in the Solis metering solution below)? Or is AC-coupled generation only observable via SolisCloud's own telemetry path when grid-tied, with no local Modbus equivalent for this model?
Happy to test register reads or provide more debug logs if useful.

[IamMattM]

Update — found the answer: checking the device's own controls in HA (Settings → Devices → Solis S6-EH1P → entities), AC Coupling Enable is OFF, and the AC Coupling Position toggle only offers two options: "off = GEN port, on = Backup port." There's no grid-tied option at all.

This confirms AC Coupling Total Active Power (and the related registers) are scoped specifically to Solis's smart-port AC-coupling feature — i.e. managing a separate AC-coupled inverter physically wired into the GEN or Backup port, typically for off-grid scenarios.

It's not a general "how much is my AC-coupled solar producing" sensor.

Since my actual PV is AC-coupled through the conventional path (not via GEN/Backup), this feature is correctly disabled, and the registers correctly read 0

#423

[IamMattM]

Feature Request added: No support for dual-meter (Grid + PV Inverter) configuration — Meter 2 registers never polled
#425