Solis EA Local Control

Home Assistant add-on that turns a Solis S6-EA single-phase hybrid inverter into a fully local, Predbat-drivable device over Modbus — no cloud, no SolisCloud dependency.

It is the active-master counterpart to the CosyLocal passive sniffer: same add-on architecture (S6 service supervision, MQTT auto-discovery, robust gateway reconnection), but instead of listening to a bus it is the Modbus master.

Built for and verified against an S6-EA1P5K-L (5 kW, AC-coupled, 32.2 kWh Fogstar) behind a Waveshare RS485→WiFi/ETH gateway. See the handover doc for the hardware story.

Why this exists

The HACS Pho3niX90/solis_modbus integration reads fine but its discharge-start slot entity is persistently flaky. The root cause is almost certainly Modbus timing: the Solis protocol requires >300 ms between frames, and the integration paces at ~50 ms. This add-on fixes that and the broader reliability problem by:

• One thread owning the RS485 bus. MQTT commands are queued; the poll loop performs every read and write. Two transactions never collide on the single-master bus.
• Spec-safe pacing (inter_frame_ms, default 400 ms) and block reads ≤ 50 registers.
• Write-then-verify: every write is echoed and independently read back, with one retry.
• Hard safety clamps in the write path (see below).
• A runtime Control Enable interlock to hard-stop all writes from the HA UI.

Hardware / gateway

Setting	Value
Gateway	Waveshare RS485 TO WIFI/ETH (Hi-Flying M2M firmware)
Gateway mode	Modbus TCP ⇔ Modbus RTU, Network A = TCP Server port 502
UART	9600 8N1
485 selector	ON · Modbus Polling OFF (gateway must not poll)
Inverter port	dedicated RS485 RJ45: pin 3 = A (green/white), pin 2 = B (orange)
Unit address	1

If you instead run the gateway in transparent mode (raw RTU over TCP, usually port 8899), set protocol: rtu_over_tcp.

⚠️ Run only ONE Modbus master on the bus. Remove/disable the HACS solis_modbus integration (and any SolaX integration) before enabling this add-on — two masters collide.

Install

1. Home Assistant → Settings → Add-ons → Add-on Store → ⋮ → Repositories, add: https://github.com/stuartj1-1981/Solis-Local
2. Install Solis EA Modbus Control, open Configuration, set gateway_host (and MQTT if you don't use the HA Mosquitto add-on), Save, Start.
3. Entities appear automatically under a device named Solis EA Inverter via MQTT discovery.

Configuration

Option	Default	Notes
gateway_host	0.0.0.0	Waveshare IP
gateway_port	502	502 for TCP⇔RTU mode
protocol	tcp	tcp or rtu_over_tcp
slave_address	1	Inverter unit address
mqtt_*	(auto)	Leave blank to auto-detect HA's MQTT service
poll_interval	10	Seconds per telemetry cycle
inter_frame_ms	400	Gap between Modbus frames (keep > 300)
enable_control	true	Expose writable control entities
max_current_a	105	Hard clamp on charge/discharge current
export_limit_w	10000	Upper clamp for export power write (DNO = 10 kW)
debug	false	Log every frame

Entities

Telemetry (sensor.*)

Battery SOC, SOH, voltage (BMS reg 33141), current, power · Inverter AC power · Grid power · PV DC power (0 — AC-coupled) · AC voltage · Grid frequency · Energy today · Inverter temperature · Battery charge/discharge state · plus a Gateway Status connectivity binary_sensor (availability + LWT).

Control (number.*, select.*, text.*, switch.*)

Entity	Type	Register(s)	Range / options
Work Mode	select	43110	Self-Use / +TOU / +TOU+Grid Charge (35)
Work Mode (raw)	sensor	43110	bitfield, diagnostic
Reserve SOC (Backup)	number	43024	0–100 %
Export Power Limit	number	43074 (×100 W)	0–export_limit_w
Charge Current Limit	number	43141	0–max_current_a A
Discharge Current Limit	number	43142	0–max_current_a A
Charge Start / End (slot 1)	text	43143/44, 43145/46	HH:MM
Discharge Start / End (slot 1)	text	43147/48, 43149/50	HH:MM
Control Enable	switch	(interlock)	ON/OFF

This add-on drives the legacy Time-Charging scheme only. The V2 Grid Time of Use registers (43707+/43753+) and the RC force registers (43135/43129) are deliberately not exposed — both are unused/no-op on the EA.

Charge End (43145/46) is inferred from the standard Solis legacy slot-1 layout (it sits between the verified charge-start and discharge-start registers). Confirm against your unit with --probe before relying on it.

Safety

• Charge/discharge current writes are clamped to max_current_a (default 105 A). A 125 A write previously caused a standby fault — the clamp makes that unreachable from HA.
• Export limit writes are clamped to export_limit_w.
• Reserve SOC 0–100; times range-checked to HH 0–23 / MM 0–59.
• Control Enable = OFF rejects every register write (and reverts the HA entity to the inverter's true value). Set enable_control: false for a fully read-only deployment.
• No EPS/EPS-backup is exposed — the EA has none; use V2L for outage cover.

Commissioning probe

Read every mapped register once and print a decoded table (no MQTT, no writes):

# from the add-on container, or any machine that can reach the gateway
python3 solis_ea.py --probe --gateway 0.0.0.0

Driving it from Predbat

Predbat controls a custom inverter through HA helper entities plus service automations it triggers — the same pattern the Predbat docs document for LuxPower/custom Modbus. Map its helpers to this add-on's entities (entity_ids are prefixed with the device name, e.g. number.solis_ea_inverter_discharge_current_limit — verify yours in Developer Tools → States).

1. SOC in kWh — Predbat needs soc_kw. Add a template sensor:

template:
  - sensor:
      - name: "Home Battery SOC kWh"
        unique_id: home_battery_soc_kwh
        unit_of_measurement: "kWh"
        device_class: energy
        state: >
          {{ (states('sensor.solis_ea_inverter_battery_soc') | float(0) / 100 * 32.2) | round(2) }}

2. apps.yaml — point Predbat at the entities and define the control services:

  soc_kw:       sensor.home_battery_soc_kwh
  soc_max:      32.2
  inverter_limit: 5000
  battery_rate_max: 5000            # ~105 A * ~48 V
  reserve:      number.solis_ea_inverter_reserve_soc_backup
  charge_rate:    number.solis_ea_inverter_charge_current_limit
  discharge_rate: number.solis_ea_inverter_discharge_current_limit
  charge_start_service:    script.solis_predbat_charge_start
  discharge_start_service: script.solis_predbat_discharge_start

Predbat's *_rate are powers (W); the add-on's current entities are amps. Either feed the rate scripts an A value (W ÷ ~48 V, then clamped to max_current_a), or map rates to your own template and only use the scripts to set the time windows.

3. The service scripts set the legacy slots via the add-on's entities. Example charge-start script (Predbat passes the window via its input_number/input_datetime helpers; adapt to your config):

script:
  solis_predbat_charge_start:
    sequence:
      - service: select.select_option
        target: { entity_id: select.solis_ea_inverter_work_mode }
        data: { option: "Self-Use + TOU + Grid Charge" }
      - service: text.set_value
        target: { entity_id: text.solis_ea_inverter_charge_start_slot_1 }
        data: { value: "{{ states('input_datetime.predbat_charge_start') [:5] }}" }
      - service: text.set_value
        target: { entity_id: text.solis_ea_inverter_charge_end_slot_1 }
        data: { value: "{{ states('input_datetime.predbat_charge_end') [:5] }}" }

Add Solcast (HACS) for the solar forecast. Keep Control Enable ON for unattended Predbat operation; it resets to ON on every add-on start.

Architecture

solis-ea-modbus/
├─ config.yaml            add-on manifest (options, schema, mqtt:need, maps)
├─ build.yaml             HA base images per arch
├─ Dockerfile            pip install paho-mqtt; copy rootfs; chmod
├─ translations/en.json   option labels
└─ rootfs/
   ├─ etc/services.d/solis-ea/{run,finish}   S6 service (bashio → env → exec)
   └─ opt/solis/solis_ea.py                  the controller

solis_ea.py = SolisModbus (TCP/RTU master, paced, verified writes) + MQTTPublisher (HA discovery, LWT, command intake → queue) + SolisController (bus-owning poll/command loop, clamps, interlock).

License

MIT (see CosyLocal).