Palletiser sequence

The brief

Client

Tamworth Foods

Site

Palletiser PAL-1, line 2

Work order

TF-2616

Industry

Food and drink

Task code

PLC-16

Difficulty

Intermediate

Type of work

Programming

Count cartons into layers with a photo-eye, push each layer onto the pallet, lower the pallet one layer height, and stop with a full-pallet lamp after the last layer. Pushing and lowering must never overlap.

What you do

1. Read the client brief and the tag table: 13 tags, 7 inputs and 4 outputs.
2. Write the logic in ladder, Structured Text or SFC.
3. Press Simulate and watch the plant answer your program.
4. Run the factory acceptance test and fix what fails.

Skills you practise

• Step sequencing
• Counting with a one-shot
• Timed output (pallet lowering)
• Interlocking movements
• Limit-switch feedback

What the test checks

The factory acceptance test runs 6 numbered tests against your program. The numbers in the brief are drawn per learner. The tests are:

• Start, Stop and E-stop run the Infeed
• Counts 5 cartons once each and stops the Infeed
• Pushes the layer out and waits for the pusher to come home
• Lowers the pallet for 1800 ms, then starts the next layer
• A full pallet of 2 layers, then Pallet removed
• Stop and E-stop end the cycle, and Start begins a fresh layer

In this lab

• Ladder, Structured Text and SFC in one studio
• A plant that answers: motors, tanks, conveyors
• Numbered tests mark your program