Error indicating the transport's circuit breaker is open: the device is
unreachable and the transport is reconnecting (or waiting to probe again),
so the request was refused without touching the wire.
This is a local error — it is never returned by modbus-rs. It is raised
by the transport when its connection state is Reconnecting or Down,
which keeps a dead device from being hammered by every caller at once.
Retryable by default: a policy with enough budget rides out the outage
cheaply, since each refused attempt costs nothing on the bus.
See
ConnectionState — The transport state that produces this error.
Error indicating the transport's circuit breaker is open: the device is unreachable and the transport is reconnecting (or waiting to probe again), so the request was refused without touching the wire.
This is a local error — it is never returned by
modbus-rs. It is raised by the transport when its connection state isReconnectingorDown, which keeps a dead device from being hammered by every caller at once.Retryable by default: a policy with enough budget rides out the outage cheaply, since each refused attempt costs nothing on the bus.
See
ConnectionState — The transport state that produces this error.