Sensor plausibility check: how the controller understands that a reading is not logical

Modern controllers do not only check whether a sensor is electrically connected, but also whether the value it provides is logical.

Example

If the supply sensor shows a much lower temperature than the return in a situation where this is not normal, the controller may consider the reading suspicious.

Cross-check

Comparisons are made between related sensors, temporal evolution, and expected behavior.

Alarm

If the value remains outside logical limits, a sensor fault may be generated.

Benefit

Plausibility logic helps identify faults that do not appear as a simple open circuit or short circuit.