TrendThief

TrendThief turns process trend screenshots, photographs and CSV data into usable control-loop information. Recover PV, SP and CV traces from existing trends, inspect and correct the extracted data, identify useful process events, fit dynamic models and compare controller tuning without rebuilding the test by hand. Built for controls engineers, technicians and process specialists working with real industrial loop data. KEY FEATURES • Digitize PV, SP and CV from screenshots and photographs • Import calibrated process data from CSV • Automatic trace extraction with colour selection and manual correction • Ruler-assisted tracing with pen snapping for straight-line repairs • Editable extracted data and engineering-unit trends • Closed-loop and open-loop event evaluation • FOPDT, SOPDT and integrating process models • Model-fit quality including R², RMSE and normalized RMSE • Current versus Proposed PID tuning comparison • Lambda-based tuning candidates • Setpoint-response and load-disturbance simulations • Predicted loop-performance and actuator-demand screening • Project, area and loop organization • Engineering notes and field-verification records • PDF loop and multi-loop engineering reports • Native iPadOS and macOS interface TrendThief uses measured CV as the process-model input. Setpoint changes can be used to identify a useful fitting window, but SP is not substituted for the actual controller output. When automatic trace recovery is uncertain, the original trend remains available for comparison. Individual traces can be recoloured, hidden, manually corrected or redrawn before fitting. The included Cedar Ridge Regional Water Treatment Plant is a fictional multi-loop demonstration project that lets you explore models, tuning comparisons and reports before using your own plant data. TrendThief is an engineering analysis aid. Model fits, predicted tuning performance and screening indicators should be reviewed against process knowledge, operating constraints and appropriate field verification before changes are applied to a live process. TrendThief Pro is available as a one-time in-app purchase for larger project workflows, data export, engineering reports and additional professional features.