Errors (Rust)¶

Core errors live in instrument_core::Error (re-exported via instrument::prelude::* as Error / Result).

Common variants¶

Variant	When
`Error::Comm`	I/O failed with address + command context
`Error::Timeout`	Operation timed out
`Error::UnsupportedKind`	Device does not support requested class
`Error::DeviceNotFound`	Address or `DeviceId` not in catalog
`Error::Backend`	VISA / backend error (boxed)
`Error::ScpiCommand`	SCPI command failed with message
`Error::Parse`	Response could not be parsed
`Error::Transport`	Low-level transport I/O / closed
`Error::MockExhausted` / `MockMismatch`	Scripted fixture mismatch

Pattern matching¶

use instrument::prelude::*;

match catalog.open_dmm(&addr) {
    Ok(mut dmm) => {
        let v = dmm.measure_voltage_dc(None)?;
        println!("{v}");
    }
    Err(Error::UnsupportedKind { address, kind, supported }) => {
        eprintln!("{address}: {kind:?} not in {supported:?}");
    }
    Err(Error::Comm { address, command, attempts, source }) => {
        eprintln!("comm @ {address} after {attempts} tries ({command:?}): {source}");
    }
    Err(e) => return Err(e),
}

Comm context¶

Retries wrap underlying failures with Error::with_comm_context(address, command, attempts) so technicians see which device and SCPI string failed.