PLC / Analog Signals & Measurement Quality
Distinguish ADC resolution from measurement accuracy
A high-resolution input can still be inaccurate because of sensor error, calibration, temperature or installation limits.
Environment and inputs: Industrial PLC / automation guidance · Verify the exact controller, module, firmware, engineering tool and machine documentation. Linked vendor examples apply to their stated products and library versions; observation, state changes and physical work require distinct authorization.
Observe and record
Compare the module's documented resolution, accuracy conditions, configured range and the sensor's own uncertainty with the process requirement.
Interpret the evidence
More bits do not automatically produce a more accurate engineering value. Quantization, noise and full measurement-chain uncertainty are different concepts.
Resolve and verify
Select a supported range and measurement design that meets the actual requirement, then validate using appropriate calibrated references and recorded acceptance criteria.
Machine and data safeguards
Do not claim improved accuracy merely because an HMI displays more decimal places.