E-CodeSecond-order step response metrics — a TI-84 Plus CE program
STEP2 is a TI-BASIC program for the TI-84 Plus CE. From the damping ratio and natural frequency: damped frequency, peak time, percent overshoot, the exact 10-90% rise time and exact 2% settling time (solved on the true response, not the rules of thumb), with the 4/(ζwn) estimate beside it.
What it asks for and what it shows
It asks for 2 values at its prompts. In the example below it shows WD, TP S, %OS, TR S, TS S, TS 4/ZW.
Example run
One of its oracle test cases: “zeta .5, wn 4”. The inputs are typed in order, and the results are the values the case expects on the screen.
| Step | Value |
|---|---|
| You enter | |
| Input 1 | 0.5 |
| Input 2 | 4 |
| The screen shows | |
WD= | 3.464101615 |
TP S= | 0.9068996821 |
%OS= | 16.30335348 |
TR S= | 0.4093932368 |
TS S= | 2.019087243 |
TS 4/ZW= | 2 |
How it's checked
6 test cases, each checked against an independent method. Replayed key by key on a virtual TI-84 Plus CE, they make 39 checks.
How E-Code checks every program
Run it or put it on your calculator
- Open the library in the TI-84 Plus CE calculator and pick “Second-order step response metrics” (STEP2).
- Put it on your own calculator with a computer and a USB cable, or type it in by hand.
Related programs
- Discrete PID step response
- Polynomial roots and stability
- Bode point and stability margins
- RC, RL and RLC transient response
- 1-DOF forced vibration
All TI-84 Plus CE engineering programs · All TI-84 Plus CE programs