Sprint 3 — Ladder Logic & Function Block Diagrams
Bolton chapter: 5
Time budget: 6–8 hours
Core concept: Ladder logic is graphical Boolean algebra disguised as a relay schematic — every rung is one logical statement evaluated left-to-right, top-to-bottom.
🎯 Sprint Goals
- Read and write ladder rungs for AND, OR, NOT, NAND, NOR, XOR, XNOR
- Build latching circuits (seal-in and SR latches)
- Recognize and avoid double-coiling, race conditions, and order-of-evaluation bugs
- Translate the same logic between LD and FBD comfortably
- Decide when LD vs. FBD is the better fit
📚 Bolton Reading
- Ch. 5 — Ladder and Functional Block Programming (full chapter)
- Cross-reference with Ch. 7 (internal relays) for latch examples
🗂️ Materials
📋 Sprint Plan
Day 1 — Read Ch. 5. Hand-draw a ladder rung for each of the 7 logic gates.
Day 2 — Open Ladder Playground. Build each gate, verify the truth table.
Day 3 — Build a seal-in latch. Then build an SR latch. Compare behavior.
Day 4 — Workbook: 10 written specs → ladder + FBD side by side.
Day 5 — Lab 02. Submit PR.
✅ Definition of Done