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Mission 59 · Pro PLC programming exercise

Never stop the filler

Coordinate three machines and two buffers as one line.

Start the line from the end, pace the labeller from Buffer 1, protect both buffers from overflowing, ride through jams without breaking bottles, and run the line out on Stop.

This mission is part of ProTry the full course, every mission and the expert challenges free for 7 days. No card needed.
The 3D packaging line control this mission runs on Pro mission
Test replay

Start from the end of the line

Test 1 of 5
Set by the testChecked by the testStep 6 of 6 · 4.2 s
Level
Expert
Time
About 90 min
Reward
+1200 XP
Rig
3D packaging line control
Siemens editors
SCL, LAD
Rockwell editors
Structured Text, Ladder
Course stage
30. Machine lab 5: expert systems
Automatic tests

What the tests check

  1. Starts from the end of the line: packer, labeller after 2 s, filler after 4 s.
  2. Labeller speed follows Buffer 1, kept between 2 and 5 bottles/s.
  3. Filler slows at 30 and stops at 36, restarting below 28.
  4. Labeller holds at Buffer 2 ≥ 36 and needs LabellerOK.
  5. Stop runs both buffers empty before stopping everything.
  1. Try it Use the buttons below the model and watch the rig respond.
  2. Test solution Every check runs on your code in one press.
  3. Replay If one fails, step through it one scan at a time to see why.
Why it matters

Where you’d see this on site

Every packaging line has a line controller doing this. Tuning the buffer levels and speeds is how plants find extra output without buying machines.

A filler that stops loses product and time it can never get back. A buffer that overruns throws bottles on the floor. A line that stops all at once leaves half-labelled product in every machine.

Where you'd find thisRun the whole line around its most important machine

On a packaging line the filler sets the pace: it is the most expensive machine, and stopping it wastes product. Every other machine runs a little faster and is paced by how full the buffers around it are, so the filler is never starved or blocked.

  1. Filler4 bottles/s
  2. Buffer 140 bottlesYou are here
  3. LabellerUp to 5/s
  4. PackerCases of 12
On a real site: places, parts and safety
  • Bottling and canning lines
  • Food and pharma packing halls
  • Any line of machines joined by conveyors

Each machine has its own guards and safety circuit; the line controller only coordinates them.

Restarting a machine after a jam is the operator's decision: the line controller never restarts a machine whose guard is open.

The sizes, timings and cutaways are teaching choices, not a drawing of any one real installation.

Keep going

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