Beckhoff PLC trainingin TwinCAT 3 Structured Text

1. 01

   Read, decide, command

   You can explain a scan and make an output follow an input.

   Lesson: Think in scansLesson: Know what a tag represents
2. 02

   Only run when allowed

   You can combine conditions and explain which request wins.

   Lesson: Build permission into the logic
3. 03

   Remember a Start request

   You can read a rung and keep a pump running until Stop.

   Lesson: Read a rung
4. 04

   Wait, then act

   You can predict an on-delay and an off-delay scan by scan.

   Lesson: Make time explicit
5. 05

   Count an event once

   You can distinguish one bottle from many scans and reset a count deliberately.

   Lesson: Count events, not scans
6. 06

   Follow a measured signal

   You can connect typed blocks and turn raw counts into useful units.

   Lesson: Follow the signal
7. 07

   Keep control steady

   You can hold demand between two thresholds and diagnose chatter.

   Lesson: Control a band, not a point
8. 08

   Ask for evidence

   You can allow valve travel time and alarm on missing feedback.

   Lesson: Separate request from evidence
9. 09

   Choose the working pump

   You can select duty or standby equipment without commanding both.

   Lesson: One request, one eligible pump
10. 10

    Acknowledge is not reset

    You can separate a condition, a latched alarm and its horn.

    Lesson: Acknowledge the horn, retain the alarm
11. 11

    Hand control over

    You can switch Auto and Manual without an unexplained command change.

    Lesson: Who controls the command?
12. 12

    One batch, clear phases

    You can describe which commands belong to each step and when to move on.

    Lesson: Describe a process in steps
13. 13

    Choose a route

    You can enter one alternative path and make competing transitions predictable.

    Lesson: One decision, one active route
14. 14

    Give commands an end

    You can distinguish N, S and R actions and reset a chart deliberately.

    Lesson: Make every command’s lifetime clear
15. 15

    Prove a safe recovery

    You can use failure evidence and require an intentional restart after interruption.

    Lesson: Prove recovery, too
16. 16

    Write phases in text

    You can write a CASE state machine and define every command in every state.

    Lesson: Write one phase as a state machine
17. 17

    Work through a collection

    You can index a typed array and use a bounded FOR loop to sum it.

    Lesson: Four values, one bounded loop
18. 18

    Keep the latest readings

    You can explain filter warm-up and replace the oldest reading correctly.

    Lesson: Remember only the latest measurements
19. 19

    Group equipment information

    You can read and write typed members of an equipment status structure.

    Lesson: Data is not executable logic
20. 20

    Reuse tested control logic

    You can run two instances of one block and prove their memory stays independent.

    Lesson: One definition, separate instances
21. 21

    Read a real transmitter

    You can turn 4–20 mA input counts into engineering units and keep them in range.

    Lesson: From milliamps to a number you can trust
22. 22

    Don’t trust a dead signal

    You can detect a broken transmitter wire and make the plant safe.

    Lesson: When the signal dies
23. 23

    Alarm limits that don’t chatter

    You can raise high and low alarms with a deadband.

    Lesson: Give alarms a deadband
24. 24

    Run a pump on a drive

    You can send a drive its run command and speed, and wait for its feedback.

    Lesson: Ask a drive, then check
25. 25

    Trip, reset, restart on purpose

    You can handle a drive trip and reset without a surprise restart.

    Lesson: Trips, resets and restarts
26. 26

    Machine lab 1: real machines, clear rules

    You can control a real machine from its pushbuttons and one measured value.

27. 27

    Machine lab 2: memory, timing and sequences

    You can remember what a machine saw, time its moves and run it through fixed stages.

28. 28

    Machine lab 3: measurements and batches

    You can control a machine from analogue measurements, and make it learn from what it measured.

29. 29

    Machine lab 4: safety sequences and plant control

    You can write sequences that prove each step, trip to a safe state on any fault, and run plant for hours.

30. 30

    Machine lab 5: expert systems

    You can build the tracking, recipe and coordination logic that real production lines depend on.

31. 31

    Capstone: run the whole factory

    You can run a whole plant from one program: utilities, a batch, a line, a robot and the safety around them.

32. 32

    Safety lab 1: stop, and restart only on purpose

    You can make an emergency stop and a guard gate stop a robot, and need a deliberate reset and start before it moves again.

33. 33

    Safety lab 2: trust nothing single

    You can read safety devices on two channels, check palm buttons and contactor feedback, and lock out on a fault.

34. 34

    Safety lab 3: how to stop, and what to let through

    You can choose between stop categories 0 and 1 and mute a light curtain for cartons but not for people.

35. 35

    Safety capstone: commission the cell

    You can bring every safety function of a robot cell together and prove each one, one device and one fault at a time.

36. 36

    Operator screens 1: grey is normal

    You can draw normal equipment calmly and flag only what needs the operator.

37. 37

    Operator screens 2: read it at a glance

    You can design an overview that answers 'is it all right?' in a second.

38. 38

    Operator screens 3: alarms in priority order

    You can sort alarms by priority and handle acknowledgement the way the alarm standards describe.

39. 39

    Operator screens 4: ask before you can't undo

    You can make an irreversible action ask first, clearly, and handle the question in the PLC.

40. 40

    Operator screens 5: same button, same place

    You can build faceplates that work the same every time and say why a button is unavailable.

• TwinCAT 3.1

  Structured Text

  Written instructions such as PumpOn := Start AND NOT Stop; with TON, TOF, CTU and R_TRIG instances you call by name. Good for maths, states and loops.

  59 exercises, starting with “Your first command”

1. Learn the idea

   26 short lessons in plain English, each with a worked example in Siemens SCL code (TwinCAT Structured Text reads almost the same, without the # signs) and a scan-by-scan trace.

2. Practise on a 3D rig

   59 missions on working pumps, tanks and a filling line. Automatic tests tell you when your code is right.

3. Check your understanding

   Short questions apply each idea to a new case. Every answer comes with an explanation.

Sites need engineers who can find faults, not only write new code. 4 missions start from an operator’s report. Run the plant, replay the failure one scan at a time and repair the logic.

• 05Stop doesn't stop itFind the path that gets round Stop.
• 13It never reaches threeSomething keeps clearing the count. Find it.
• 36Empty until a fifth fullThe level reads 0% while the tank fills. Find out why.
• 41It started on its ownAfter a drive reset the pump restarted. Find the memory that survived the trip.

There is no TwinCAT export file yet. Your code is plain IEC 61131-3 Structured Text, written the TwinCAT way: copy it into an ST POU in TwinCAT 3 and declare the same variables in its VAR section.