Industrial Engineer · phase 3 of 16
Continuous / Cyclic Task
Task that runs repeatedly whenever higher-priority work and system overhead permit.
The Explain card
- Plain English
- A continuous task runs the moment it finishes, over and over, as fast as the controller can go once higher priority work is done. It has no fixed period, only a scan time that floats.
- Example
- The default task on most controllers is continuous. All the machine logic sits in it, and its scan time drifts between 5 and 12 milliseconds depending on what else is happening.
- Why it matters
- Anything that needs a known rate cannot live here, because the rate changes with load. It is the right place for the bulk of the logic and the wrong place for anything timed by counting scans.
- Hook
- Runs whenever nothing more important is running.
Where it sits in the deck
Phase 3: PLC Program Organization and Execution
How the logic is arranged and how the scan actually runs it, which is the difference between code that works and code that works every time.
