Competency and practice field guide
Button-and-light PLC curriculum scenario: practice plan
Direct answer
The learner can predict the input image, rung result and output state for pressed and released conditions and explain the scan boundary.
Written for first-time PLC learners connecting one momentary input to one output before adding memory, timing or sequence complexity.
Scope
Button normal state, input address, tag meaning, contact instruction, rung continuity, output owner, lamp state, scan order and stop expectation.
Signal path
Physical or simulated button through input sampling, Boolean instruction, rung result, output image and visible lamp result.
Baseline practice
Press and release produce one predictable state at every boundary over repeated scans.
Edge cases
Normally-open versus normally-closed confusion, stuck input, duplicate output, scan transition, force, restart and physical-versus-logical inversion.
Fault practice
A button, input, tag, contact instruction, rung, output owner, channel or lamp mismatch.
Transfer to the job
The behavior recreated in the intended PLC dialect and supervised low-energy wiring exercise.
What does a beginner learn from a PLC button-and-light exercise?
It establishes the complete evidence chain from field state and input tag through one Boolean decision to an output command and visible result.
Why can a highlighted rung still leave the light off?
The highlighted condition may not own the final output, the output may be forced or inhibited, or the electrical and load layers may disagree with logic.