Lessons · Industrial control · rungs
One line of a ladder
A rung is conditions on the left and an output on the right: if the contacts pass power, the coil energises.
Hone is a place to practise programming. This is one of its lessons, written out in full and free to read without an account.
What it is for
It is how relay panels were wired, so electricians and engineers read it the same way. Every PLC program is rungs.
How to think about it
What must be true, and what happens? Read left to right: what must be true (contacts), then what happens (coil). One rung, one idea.
Worked example
[DoorClosed] [KeyOn] (Ready)Ready is on while the door is closed AND the key is on.
Your turn
Lamp on while Switch is on.
[Switch] ()
Run a rung and watch the scan
The trap
Putting two coils on one rung. Each output gets its own rung.
Practise rungs on HoneA question on it now, a coding challenge where there is one, and it is remembered for review. Free, no email needed.