Error Behaviour

The integration distinguishes between transient connection problems, broken profiles, authentication/licence problems and missing values.

Situation	Behaviour	User action
Register decodes to None	Sensor is unknown	Check profile type/scale
Modbus timeout	UpdateFailed, all register sensors unavailable, timeout counter increments	Check network and gateway
Connection lost	TCP transport closed, next poll reconnects	Check device power/network
Modbus exception	UpdateFailed, exception code in statistics	Check unit id, address, access
Invalid profile at setup	ConfigEntryError	Fix the JSON file and restart
Device unreachable at setup	ConfigEntryNotReady, Home Assistant retries	Check host and port
Licence signature invalid	LicenseError; stored licence rejected; trial/free remains	Request a new licence
Licence bound to another instance	LicenseError	Licence must match this instance id
Licence expired	14-day grace, then basic sensors	Renew licence
Write without Pro	HomeAssistantError	Activate Pro
Write with option off	HomeAssistantError	Enable write access in options
Support token request fails	HomeAssistantError, no session	Check licence server URL
Support provider unavailable	HomeAssistantError, no session	Check provider configuration

Modbus exception codes

Code	Name
1	illegal function
2	illegal data address
3	illegal data value
4	server device failure
5	acknowledge
6	server device busy
8	memory parity error
10	gateway path unavailable
11	gateway target failed to respond

Diagnostics

The connection binary sensor exposes counters:

• requests, successes, failures
• timeouts, exceptions, protocol_errors, reconnects
• last_error, last_exception_code, last_success, last_latency_ms
• the last ten error messages

The diagnostics download contains the full snapshot plus a register dump and a domain-filtered log excerpt.