ModbusTimeoutErrors happening frequently after ~1yr uptime.

[hamid-elaosta]

Hey folks. I don't suspect this is a bug so I've raised it as a discussion. I have been using my Sunsynk 7kW Hybrid inverter with a USR-W630 (I wrote the doc on configuring it).

I was doing a bit of maintenance on HA and noticed I'm getting a lot of Modbus timeouts; I'm not sure if they're new or if they've been happening for a while; They certainly weren't happening a few months ago when I last checked.

I've tried rebooting the USR-W630, I've power cycled it fully, re-seated the cables, tried switching to pymodbus-tcp, I've slowed down the requests, and I've toggled the press-button on/off on the inverter (though I haven't fully power cycled it). I also removed the e-linter since I'm not using it and had it blocked from accessing the internet. I've investigated WiFi connectivity to the W630 and it's solid and low-latency, I've thrown Claude at it, no conclusion so far.

Nothing seems to have helped. My question is; has anyone got any idea what the cause might be? Cause the W630 be failing? Could it be the inverter? Any tips on how I can check or rule out certain things?

App version: Sunsynk or Deye Inverter add-on (multi) - 1.3.0

Configuration:

INVERTERS:
  - SERIAL_NR: '24051XXXXX'
    HA_PREFIX: sunsynk
    MODBUS_ID: 1
    DONGLE_SERIAL_NUMBER: '0'
    PORT: tcp://10.0.66.129:8899
SENSOR_DEFINITIONS: single-phase
SENSORS:
  - energy_management
  - power_flow_card
  - battery_soc
  - battery_temperature
  - dc_transformer_temperature
  - radiator_temperature
  - date_time
  - pv1
  - pv2
SENSORS_FIRST_INVERTER:
  - settings
MANUFACTURER: Sunsynk
READ_ALLOW_GAP: 2
READ_SENSORS_BATCH_SIZE: 8
READ_MESSAGE_SPACING: 0.2
READ_ATTEMPTS: 3
TIMEOUT: 3
STALE_INVERTER_AFTER_SECONDS: 120
STALE_INVERTER_SKIP_SECONDS: 600
SCHEDULES:
  - KEY: W
    READ_EVERY: 10
    REPORT_EVERY: 60
    CHANGE_ANY: false
    CHANGE_BY: 80
    CHANGE_PERCENT: 0
  - KEY: battery_soc
    READ_EVERY: 30
    REPORT_EVERY: 300
    CHANGE_ANY: true
NUMBER_ENTITY_MODE: box
PROG_TIME_INTERVAL: '15'
MQTT_HOST: core-mosquitto
MQTT_PORT: 1883
MQTT_USERNAME: sunsynk
MQTT_PASSWORD: <redacted>

Note it's always the first attempt (and only the first attempt) that fails:

[15:40:35] ERROR   Read register 164 x6: ModbusTimeoutError: read_holding_registers(164, 6): Response timeout after 3 seconds for transaction with ID 0x662b [attempt 1/3]
[15:41:24] ERROR   Read register 217 x3: ModbusTimeoutError: read_holding_registers(217, 3): Response timeout after 3 seconds for transaction with ID 0x66b1 [attempt 1/3]
[15:44:10] ERROR   Read register 255 x7: ModbusTimeoutError: read_holding_registers(255, 7): Response timeout after 3 seconds for transaction with ID 0x685c [attempt 1/3]
[15:44:34] ERROR   Read register 109 x4: ModbusTimeoutError: read_holding_registers(109, 4): Response timeout after 3 seconds for transaction with ID 0x6896 [attempt 1/3]
[15:45:19] ERROR   Read register 150 x1: ModbusTimeoutError: read_holding_registers(150, 1): Response timeout after 3 seconds for transaction with ID 0x690f [attempt 1/3]
[15:45:33] ERROR   Read register 90 x2: ModbusTimeoutError: read_holding_registers(90, 2): Response timeout after 3 seconds for transaction with ID 0x6934 [attempt 1/3]
[15:46:13] ERROR   Read register 172 x1: ModbusTimeoutError: read_holding_registers(172, 1): Response timeout after 3 seconds for transaction with ID 0x699d [attempt 1/3]
[15:46:23] ERROR   Read register 243 x2: ModbusTimeoutError: read_holding_registers(243, 2): Response timeout after 3 seconds for transaction with ID 0x69b5 [attempt 1/3]
[15:46:33] ERROR   Read register 268 x8: ModbusTimeoutError: read_holding_registers(268, 8): Response timeout after 3 seconds for transaction with ID 0x69cd [attempt 1/3]
[15:46:43] ERROR   Read register 276 x4: ModbusTimeoutError: read_holding_registers(276, 4): Response timeout after 3 seconds for transaction with ID 0x69e6 [attempt 1/3]
[15:48:06] ERROR   Read register 190 x5: ModbusTimeoutError: read_holding_registers(190, 5): Response timeout after 3 seconds for transaction with ID 0x6abc [attempt 1/3]
[15:49:05] ERROR   Read register 172 x1: ModbusTimeoutError: read_holding_registers(172, 1): Response timeout after 3 seconds for transaction with ID 0x6b55 [attempt 1/3]
[15:49:12] ERROR   Read register 232 x1: ModbusTimeoutError: read_holding_registers(232, 1): Response timeout after 3 seconds for transaction with ID 0x6b62 [attempt 1/3]
[15:50:52] ERROR   Read register 268 x8: ModbusTimeoutError: read_holding_registers(268, 8): Response timeout after 3 seconds for transaction with ID 0x6c68 [attempt 1/3]
[15:52:43] ERROR   Read register 166 x4: ModbusTimeoutError: read_holding_registers(166, 4): Response timeout after 3 seconds for transaction with ID 0x6d84 [attempt 1/3]
[15:54:51] ERROR   Read register 232 x1: ModbusTimeoutError: read_holding_registers(232, 1): Response timeout after 3 seconds for transaction with ID 0x6ed2 [attempt 1/3]
[15:55:10] ERROR   Read register 255 x7: ModbusTimeoutError: read_holding_registers(255, 7): Response timeout after 3 seconds for transaction with ID 0x6f08 [attempt 1/3]
[15:55:40] ERROR   Read register 276 x4: ModbusTimeoutError: read_holding_registers(276, 4): Response timeout after 3 seconds for transaction with ID 0x6f58 [attempt 1/3]
[15:56:29] ERROR   Read register 276 x4: ModbusTimeoutError: read_holding_registers(276, 4): Response timeout after 3 seconds for transaction with ID 0x6fd9 [attempt 1/3]
[15:56:59] ERROR   Read register 276 x4: ModbusTimeoutError: read_holding_registers(276, 4): Response timeout after 3 seconds for transaction with ID 0x7027 [attempt 1/3]
[15:57:58] ERROR   Read register 247 x8: ModbusTimeoutError: read_holding_registers(247, 8): Response timeout after 3 seconds for transaction with ID 0x70c0 [attempt 1/3]
[15:59:29] ERROR   Read register 276 x4: ModbusTimeoutError: read_holding_registers(276, 4): Response timeout after 3 seconds for transaction with ID 0x71ad [attempt 1/3]
[16:00:19] ERROR   Read register 154 x1: ModbusTimeoutError: read_holding_registers(154, 1): Response timeout after 3 seconds for transaction with ID 0x722c [attempt 1/3]
[16:01:19] ERROR   Read register 150 x1: ModbusTimeoutError: read_holding_registers(150, 1): Response timeout after 3 seconds for transaction with ID 0x72c7 [attempt 1/3]
[16:03:08] ERROR   Read register 276 x4: ModbusTimeoutError: read_holding_registers(276, 4): Response timeout after 3 seconds for transaction with ID 0x73e5 [attempt 1/3]
[16:04:03] ERROR   Read register 79 x1: ModbusTimeoutError: read_holding_registers(79, 1): Response timeout after 3 seconds for transaction with ID 0x7470 [attempt 1/3]
[16:04:33] ERROR   Read register 59 x1: ModbusTimeoutError: read_holding_registers(59, 1): Response timeout after 3 seconds for transaction with ID 0x74bd [attempt 1/3]
[16:05:58] ERROR   Read register 217 x3: ModbusTimeoutError: read_holding_registers(217, 3): Response timeout after 3 seconds for transaction with ID 0x75a0 [attempt 1/3]
[16:09:09] ERROR   Read register 243 x2: ModbusTimeoutError: read_holding_registers(243, 2): Response timeout after 3 seconds for transaction with ID 0x7790 [attempt 1/3]
[16:09:19] ERROR   Read register 150 x1: ModbusTimeoutError: read_holding_registers(150, 1): Response timeout after 3 seconds for transaction with ID 0x77a7 [attempt 1/3]
[16:11:16] ERROR   Read register 276 x4: ModbusTimeoutError: read_holding_registers(276, 4): Response timeout after 3 seconds for transaction with ID 0x78db [attempt 1/3]
[16:11:26] ERROR   Read register 190 x1: ModbusTimeoutError: read_holding_registers(190, 1): Response timeout after 3 seconds for transaction with ID 0x78f3 [attempt 1/3]
[16:13:37] ERROR   Read register 243 x2: ModbusTimeoutError: read_holding_registers(243, 2): Response timeout after 3 seconds for transaction with ID 0x7a48 [attempt 1/3]
[16:15:04] ERROR   Read register 90 x2: ModbusTimeoutError: read_holding_registers(90, 2): Response timeout after 3 seconds for transaction with ID 0x7b27 [attempt 1/3]
[16:16:03] ERROR   Read register 22 x3: ModbusTimeoutError: read_holding_registers(22, 3): Response timeout after 3 seconds for transaction with ID 0x7bc1 [attempt 1/3]
[16:17:34] ERROR   Read register 154 x1: ModbusTimeoutError: read_holding_registers(154, 1): Response timeout after 3 seconds for transaction with ID 0x7cb0 [attempt 1/3]
[16:18:14] ERROR   Read register 186 x2: ModbusTimeoutError: read_holding_registers(186, 2): Response timeout after 3 seconds for transaction with ID 0x7d18 [attempt 1/3]
[16:18:24] ERROR   Read register 276 x4: ModbusTimeoutError: read_holding_registers(276, 4): Response timeout after 3 seconds for transaction with ID 0x7d32 [attempt 1/3]