Control System Calc vs My LoopCal

Control System Calc (ControlCalc) is an engineering tool for control engineers, R&D staff and students. Enter a transfer function to perform PID tuning, frequency-domain analysis and time-domain simulation — turning textbook control theory into a pocket tool you can use anywhere. All calculations run locally on your device, no internet required. KEY FEATURES ■ PID Tuning Five classic tuning methods built in: Ziegler-Nichols open-loop step, Cohen-Coon, Ziegler-Nichols closed-loop ultimate, plus IMC-Lambda and AMIGO. Each method includes guidance on when to use it. ■ Closed-Loop Step Simulation Simulate the closed-loop step response with an FOPDT model and a PID controller with derivative filtering. View the control effort u(t) to spot actuator saturation, and fine-tune parameters by hand. ■ Bode Plot & Stability Margins Draw magnitude and phase curves on a log scale, with automatic 0 dB / −180° reference lines, gain margin, phase margin and crossover frequencies — stability at a glance. ■ Step Response & Performance Metrics RK4 time-domain simulation that automatically computes overshoot, rise time and settling time. ■ Second-Order Designer Back-solve system parameters from overshoot Mp / settling time ts, or from damping ratio ζ / natural frequency ωn, then push them to the step-response page in one tap. ■ Root Locus & Nyquist (Pro) Root-locus branch tracing with the imaginary-axis stability boundary, an equal-aspect Nyquist plot with unit circle, plus pole/stability analysis for deeper insight. THOUGHTFUL DETAILS • Built-in library of classic example models — tap to load and go • Draggable readouts on time-domain curves (live t / y display) • Numeric keyboard with a Done button; input parameters persist automatically • Simplified Chinese / English / German / Japanese, switchable in-app instantly PRO UPGRADE (one-time purchase) • Removes all ads • Unlocks IMC-Lambda / AMIGO tuning methods • Unlocks Nyquist plot, root locus and pole/stability analysis • Unlocks CSV data export Buy once, keep forever. Family Sharing supported. WHO IS IT FOR Control, electrical, mechatronics and process engineers, R&D and commissioning staff, students taking control-theory courses, and anyone who needs to quickly validate a control-system design. DISCLAIMER All results are provided for engineering reference only. Real-world system design and commissioning should combine field conditions with professional judgment. Have feedback or questions? Contact us from the Settings page.

LoopCal turns a 4–20 mA loop check into a calibration worksheet you can hand over, and it is the quickest way to convert a signal in the field. Built for instrumentation and calibration technicians. Fully offline. FROM CHECK TO WORKSHEET • Guided three-point, five-point, and custom 2–21-point checks • As-found and as-left runs, with the error and pass/fail at every point • Up-scale and down-scale readings with hysteresis • Tolerance as percent of span, signal units, or engineering units • Worst point and maximum error summarized for you • A clean PDF worksheet with your company name and logo, in US Letter or A4, plus CSV for your records CONVERT IN SECONDS • 4–20 mA, 0–20 mA, 0–10 V, 1–5 V, and your own custom signal endpoints • Direct-acting and reverse-acting ranges • Linear and square-root (flow) transfer functions • Engineering ranges with any unit, including negative and offset spans • Percent, signal, and engineering values update as you type, with the substituted formula shown • Verify this loop: take the range you just entered straight into a check EVERY INSTRUMENT ON RECORD • Save instruments with their ranges and calibration history • See what is coming due, and get a reminder before the next calibration • Reopen a saved instrument and start its next check without retyping the range LOOP POWER MATH • Shunt resistor voltage drop • Required supply voltage and remaining compliance • Maximum loop and wire resistance PRIVATE BY DESIGN • Everything runs on your device. No account, no ads, no tracking, no network. LoopCal is a calculation aid and field worksheet — not a calibrator, an accredited calibration service, or a replacement for manufacturer procedures. Always follow site lockout/tagout, operations authorization, device manuals, and approved procedures. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/