Across
- 3. An output instruction in ladder logic that energizes (turns on) a bit, internal memory location, or physical output device when the rung conditions are true.
- 5. A single horizontal line of logic in a ladder diagram containing contacts, coils, and other instructions; multiple rungs form a program.
- 6. A memory function (often implemented with a seal-in contact or SET/RESET instructions) that keeps an output on after the initiating input has been removed until an unlatch condition occurs.
Down
- 1. The continuous operating cycle of a PLC: read inputs → solve the ladder logic → update outputs. Typically repeats every few milliseconds.
- 2. A PLC instruction (TON, TOF, or RTO) that measures or delays time based on an enable condition, used for sequencing, alarms, and delays.
- 4. An input instruction in ladder logic (normally open or normally closed) that represents a condition which must be true for logic to continue.
- 6. A graphical programming language that visually resembles electrical ladder diagrams; power flows left-to-right through contacts to energize coils.