Reading devices

Introduced in: rtd-acquire 0.1.0a1

The common application boundary is intentionally small:

measurement = device.read()

Anything satisfying the AcquisitionDevice protocol can be used where your application expects that contract.

from rtd_acquire import AcquisitionDevice, Measurement


def read_resistance(device: AcquisitionDevice) -> float:
    measurement: Measurement = device.read()
    if measurement.resistance_ohms is None:
        raise RuntimeError("acquisition returned a fault measurement")
    return measurement.resistance_ohms

A read is one acquisition operation

The base protocol does not promise thread safety or reentrancy. Unless a specific device documents stronger behavior, serialize access to a device instance.

Device result versus operation failure

A device can successfully communicate with hardware and return a Measurement whose status is warning or fault. That is different from the acquisition operation itself failing, which raises AcquisitionError.

Keep those two cases separate in application logic; they carry different information.