Hi,
I try to setup a modbus connection between HA and a Growatt inverter. I bought a Modbus USB module. Iam running the 2025.5 HA verson on Proxmox. I do see the Modbus module in HA (see printscreen) but get an error. What do I wrong?
My coral USB and Zigbee USB sticks are working fine. So the passtrough Proxmox seems to work fine + I do see the Modbus USB module in HA
2025-06-17 19:07:02.173 WARNING (MainThread) [pymodbus.logging] Failed to connect [Errno 11] Could not exclusively lock port /dev/ttyUSB0: [Errno 11] Resource temporarily unavailable
2025-06-17 19:07:02.274 ERROR (MainThread) [custom_components.growatt_local.config_flow] Unexpected error when trying to get device info
Traceback (most recent call last):
File "/config/custom_components/growatt_local/config_flow.py", line 264, in async_step_serial
device_info = await get_device_info(server, user_input[CONF_ADDRESS])
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/config/custom_components/growatt_local/API/growatt.py", line 460, in get_device_info
inverter_v120 = await device.get_device_info(HOLDING_REGISTERS_120, minimal_length, unit)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/config/custom_components/growatt_local/API/growatt.py", line 95, in get_device_info
await self.read_holding_registers(item[0], count=item[1], slave=slave)
File "/config/custom_components/growatt_local/API/growatt.py", line 152, in read_holding_registers
data = await self.client.read_holding_registers(start_address, count=count, slave=slave)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.13/site-packages/pymodbus/client/mixin.py", line 114, in read_holding_registers
return self.execute(no_response_expected, pdu_reg.ReadHoldingRegistersRequest(address=address, count=count, dev_id=slave))
~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/local/lib/python3.13/site-packages/pymodbus/client/base.py", line 86, in execute
raise ConnectionException(f"Not connected[{self!s}]")
pymodbus.exceptions.ConnectionException: Modbus Error: [Connection] Not connected[AsyncModbusSerialClient /dev/ttyUSB0:0]
2025-06-17 19:07:02.482 ERROR (MainThread) [pymodbus.logging] No response received after 3 retries, continue with next request
