Errors and status

Introduced in: rtd-acquire 0.1.0a1

rtd-acquire separates invalid configuration, acquisition-operation failures, and hardware-reported measurement diagnostics.

Exceptions

RtdAcquireError is the package exception base class.

• ConfigurationError — caller configuration is invalid or an optional backend required for that configuration is unavailable.
• AcquisitionError — the acquisition operation itself could not complete, for example because an SPI transfer failed.

from rtd_acquire import AcquisitionError, ConfigurationError

try:
    measurement = device.read()
except ConfigurationError:
    # Fix configuration rather than retrying unchanged.
    raise
except AcquisitionError:
    # Communication/acquisition did not complete.
    raise

Measurement status is not an exception

A successfully completed acquisition can still return warning or fault evidence. Inspect the returned Measurement:

if measurement.status == "fault":
    for diagnostic in measurement.diagnostics:
        print(diagnostic.code, diagnostic.message)

A fault measurement has resistance_ohms is None. A warning may still carry a usable resistance because the evidence does not necessarily invalidate the measurement.