Basic
15 min

Sortation Diverter

conveyormaterial-handlingdiverteritem-trackingone-shot
Sortation Diverter scenario preview

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Briefing

A material-handling conveyor feeds items through a photoeye at the entry zone. Each item carries an RFID-style tag identifying it as Type A or Type B. When the photoeye pulses, you must sample the TAG_A and TAG_B inputs immediately, then after a 500 ms travel delay energise the correct diverter for 1 s to route the item. An invalid tag combination (both or neither set) latches ERROR_LAMP.

Objectives

  • CONVEYOR_RUN must be on whenever STOP_PB is not pressed
  • When PHOTOEYE_IN pulses, latch the TAG_A and TAG_B values for the current item
  • After ~500 ms, energise DIVERTER_A_ENERGISE for 1 s if the item is Type A
  • After ~500 ms, energise DIVERTER_B_ENERGISE for 1 s if the item is Type B
  • If both tags or neither tag read, latch ERROR_LAMP (no diverter action)
  • ERROR_LAMP stays latched until power-cycle (or STOP_PB clears it in this simulation)

Hints

  • Use a ONE_SHOT on PHOTOEYE_IN rising edge to capture tag values into latched bits: ITEM_A and ITEM_B
  • Use a TOF or TON timer for the 500 ms travel delay before energising the diverter
  • Use a second TON (1 s) to hold each diverter energised: DIVERTER_A_ENERGISE := TON_A.Q
  • Validate: ERROR_BIT := (ITEM_A AND ITEM_B) OR (NOT ITEM_A AND NOT ITEM_B) — set on each PHOTOEYE_IN pulse
  • STOP_PB de-energises CONVEYOR_RUN and may be used to clear the error latch

I/O Table

Inputs

PHOTOEYE_IN

Photoeye pulse — item at entry zone

BOOL · %I0.0

TAG_A

Tag read: item is Type A

BOOL · %I0.1

TAG_B

Tag read: item is Type B

BOOL · %I0.2

DIVERTER_A_HOME

Diverter A at home position

BOOL · %I0.3

DIVERTER_B_HOME

Diverter B at home position

BOOL · %I0.4

STOP_PB

Stop / E-stop push-button

BOOL · %I0.5

Outputs

CONVEYOR_RUN

Conveyor drive run

BOOL · %Q0.0

DIVERTER_A_ENERGISE

Diverter A solenoid (energise to divert A)

BOOL · %Q0.1

DIVERTER_B_ENERGISE

Diverter B solenoid (energise to divert B)

BOOL · %Q0.2

ERROR_LAMP

Error indicator lamp (latching)

BOOL · %Q0.3

Your program will be tested against:

All test cases run automatically when you submit. Assertions are hidden until you pass.

  1. #1CONVEYOR_RUN asserts when not stopped

    With no STOP_PB, CONVEYOR_RUN must be on from the first scan

  2. #2STOP_PB stops the conveyor

    Press STOP_PB; CONVEYOR_RUN must de-energise immediately

  3. #3Type-A item energises Diverter A

    Inject a Type-A item; after photoeye + travel delay, DIVERTER_A_ENERGISE must pulse

  4. #4Type-B item energises Diverter B

    Inject a Type-B item; DIVERTER_B_ENERGISE must pulse

  5. #5Both tags simultaneously latches ERROR_LAMP

    Manually assert PHOTOEYE_IN + TAG_A + TAG_B together; ERROR_LAMP must latch

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Runnable simulator field guide

PLC sortation diverter scenario: implementation, evidence and troubleshooting

Direct answer

PLC sortation diverter scenario becomes useful when it connects entry edge, product identity, class, conveyor state, travel delay, divert window, actuator feedback, destination sensor, counts and reject state with sensor event through tracking record, time or position model, classification decision, output command, mechanism response and destination confirmation, then proves normal products and divert products each receiving one decision and one confirmed destination without duplicated counts under normal, boundary, fault and recovery conditions. The objective is a repeatable engineering or learning result, not merely activity inside a page or tool.

This guide is written for pLC learners programming a conveyor diverter with classification input, product tracking and destination proof. The intended result is specific: the learner can create one event per product, schedule one actuation, prevent double counts and recover tracking from stops or missing confirmation.

a guarded conveyor sortation cell with three destinations, photoelectric sensing, pneumatic diversion and package confirmation while studying sensor-triggered package classification, divert timing, confirmation and count reconciliation
This unbranded training scene makes the boundaries for sensor-triggered package classification, divert timing, confirmation and count reconciliation visible so normal, abnormal and recovery evidence can be compared without implying target-equipment validation.

System map / 02

Six concepts that control the result

Treat these as connected checkpoints. Each checkpoint has an expected state, an observable state and a boundary to the next part of the system. That structure prevents a software indication from being mistaken for physical proof.

NODE 01observable

Define the operating contract

entry edge, product identity, class, conveyor state, travel delay, divert window, actuator feedback, destination sensor, counts and reject state. For sensor-triggered package classification, divert timing, confirmation and count reconciliation, record the initial condition, actor, requested change, observable result and stopping condition before selecting a tool or implementation.

NODE 02observable

Map the evidence path

sensor event through tracking record, time or position model, classification decision, output command, mechanism response and destination confirmation. Separate request, internal state, output or service, physical or user-visible result and independent feedback so each boundary can be inspected.

NODE 03observable

Prove normal operation

normal products and divert products each receiving one decision and one confirmed destination without duplicated counts. Run more than one cycle from a known state and retain the values, timings or artifacts that demonstrate repeatability.

NODE 04observable

Exercise a boundary case

sensor chatter, back-to-back products, missing class, late response, failed confirmation, jam, stop during transit, restart and manual removal. Choose minimum, maximum, simultaneous, delayed or restart conditions that reveal assumptions hidden by the happy path.

NODE 05observable

Diagnose a controlled fault

an event, identity, classification, tracking, timing, output, actuator, destination, count or recovery mismatch. Preserve the first symptom, divide the system at a measurable boundary and change one condition only after predicting the result.

NODE 06observable

Transfer and hand over

the model compared with measured conveyor travel, actuator response, sensor placement and safe recovery on target equipment. Restore normal state, remove temporary changes, repeat affected checks and document which claims remain limited to the learning environment.

Procedure / 03

A six-step practice and commissioning workflow

Run the steps in order the first time. Later, the same structure becomes a diagnostic loop: define the expected condition, observe the boundary, interpret the difference and choose one proving action.

  1. 01

    Write the acceptance case

    Convert entry edge, product identity, class, conveyor state, travel delay, divert window, actuator feedback, destination sensor, counts and reject state into initial conditions, one stimulus and observable pass criteria.

    Evidence: Another person can repeat the case without guessing the intended result.

    Avoid: Using page completion or an animation as the acceptance criterion.

  2. 02

    Build the map

    Document sensor event through tracking record, time or position model, classification decision, output command, mechanism response and destination confirmation and name who owns each state or decision.

    Evidence: Every request and result has a source, destination and useful inspection point.

    Avoid: Using the same value as command, status and independent feedback.

  3. 03

    Run the baseline

    Apply normal products and divert products each receiving one decision and one confirmed destination without duplicated counts from a clean start and record the expected evidence.

    Evidence: Repeated runs produce the same bounded result.

    Avoid: Changing several parameters before a baseline exists.

  4. 04

    Challenge assumptions

    Test sensor chatter, back-to-back products, missing class, late response, failed confirmation, jam, stop during transit, restart and manual removal without changing the acceptance contract.

    Evidence: Limits, timing and restart behavior reach defined states.

    Avoid: Testing only one ideal sequence.

  5. 05

    Isolate one failure

    Introduce or analyse an event, identity, classification, tracking, timing, output, actuator, destination, count or recovery mismatch and locate the first disagreement.

    Evidence: The proving action distinguishes the leading hypotheses.

    Avoid: Resetting, forcing or replacing before evidence is retained.

  6. 06

    Close the evidence loop

    Complete the model compared with measured conveyor travel, actuator response, sensor placement and safe recovery on target equipment and repeat the affected regression cases.

    Evidence: A run is complete only when the requested behavior, stop behavior, fault response and recovery are observable from a fresh initial condition.

    Avoid: Treating an acknowledged message or one successful rerun as handover.

Diagnostic matrix / 04

Symptoms, proving points and next actions

The table is a reasoning aid, not a parts-replacement chart. Preserve the initial symptom, inspect the named boundary and use the interpretation to choose the next controlled test. Site safety procedures and equipment manuals remain authoritative.

Diagnostic symptoms, inspection points, interpretations and next actions for PLC sortation diverter scenario: implementation, evidence and troubleshooting
Observed symptomInspectInterpretationNext proving action
The expected result is unclearRequirement, initial state, actor, stimulus, units and pass conditionThe operator, programmer and reviewer may be solving different versions of the task.Rewrite one observable acceptance case before continuing.
Internal state changes but the outcome does notRequest, final owner, output or service boundary and independent feedbackA software or interface indication proves intent at one layer, not the complete outcome.Trace the first boundary after the changing state.
Normal case passes but an edge case failsLimits, timing, simultaneous events, reset and restart assumptionsThe implementation contains a hidden assumption exposed by the changed condition.Add the failed boundary as a permanent regression case.
The failure disappears after resetOriginal symptom, histories, diagnostics, timestamps and active causeReset changed evidence or state without proving the initiating cause.Reproduce under a controlled condition and preserve pre/post-event data.
Simulator and target disagreeModel boundary, software version, task timing, I/O behavior, data types and configurationA learning model and the intended target do not share one of the recorded assumptions.Reduce the case and verify against current target documentation.
The result cannot be explainedPrediction, observation, proving action, alternative hypotheses and limitationsActivity occurred but the evidence is not yet transferable or reviewable.Have the learner defend the signal path and repeat a changed case.

Product evidence / 05

What the browser practice can actually demonstrate

The browser runtime joins editable control state to visible I/O and machine or process behavior, allowing the same initial conditions and stimuli to be replayed.

Where simulation stops

The browser model is not a digital twin of a selected sorter and cannot validate physical timing, pneumatic response, guarding or throughput.

Commissioning notebook / 06

Six cases that turn the concepts into evidence

Use these as written briefs rather than click-through instructions. For every case, state the expected condition before acting, retain the first useful observation and explain why the final result proves the requirement. A different program or component choice can still be correct when it produces the same bounded behavior and evidence.

Case 01

predict → observe → prove

Prove define the operating contract

Engineering context. entry edge, product identity, class, conveyor state, travel delay, divert window, actuator feedback, destination sensor, counts and reject state. For sensor-triggered package classification, divert timing, confirmation and count reconciliation, record the initial condition, actor, requested change, observable result and stopping condition before selecting a tool or implementation. Begin with a written normal condition and identify which request, state, physical result or communication value will provide independent confirmation. Do not begin by changing the configuration; the initial state is part of the evidence and should remain reproducible.

Controlled setup. Use the “Write the acceptance case” stage of the workflow: convert entry edge, product identity, class, conveyor state, travel delay, divert window, actuator feedback, destination sensor, counts and reject state into initial conditions, one stimulus and observable pass criteria. The acceptance record should show this result: another person can repeat the case without guessing the intended result. Record initial conditions, the exact stimulus and the observation point so another learner can repeat the case without relying on your memory.

Fault challenge. Introduce or analyse “The expected result is unclear” as one bounded deviation. Inspect requirement, initial state, actor, stimulus, units and pass condition The working interpretation is that the operator, programmer and reviewer may be solving different versions of the task. The next proving action is to rewrite one observable acceptance case before continuing. Change only one condition before observing the result, and preserve timestamps or measurements where timing matters.

Review and recovery. The most common trap here is using page completion or an animation as the acceptance criterion. After restoring the cause, repeat the normal case and at least one stop, timeout, disconnect or restart boundary relevant to this topic. Remove temporary forces and bypasses, return the model to a known state and retain the evidence that both operation and recovery are deliberate.

Explain it aloud: How do I time a PLC conveyor diverter? A defensible short answer is: Measure or model travel from the identification sensor to the diverter, retain the product decision and command inside a window that includes speed and actuator-response tolerances.

Case 02

predict → observe → prove

Prove map the evidence path

Engineering context. sensor event through tracking record, time or position model, classification decision, output command, mechanism response and destination confirmation. Separate request, internal state, output or service, physical or user-visible result and independent feedback so each boundary can be inspected. Begin with a written normal condition and identify which request, state, physical result or communication value will provide independent confirmation. Do not begin by changing the configuration; the initial state is part of the evidence and should remain reproducible.

Controlled setup. Use the “Build the map” stage of the workflow: document sensor event through tracking record, time or position model, classification decision, output command, mechanism response and destination confirmation and name who owns each state or decision. The acceptance record should show this result: every request and result has a source, destination and useful inspection point. Record initial conditions, the exact stimulus and the observation point so another learner can repeat the case without relying on your memory.

Fault challenge. Introduce or analyse “Internal state changes but the outcome does not” as one bounded deviation. Inspect request, final owner, output or service boundary and independent feedback The working interpretation is that a software or interface indication proves intent at one layer, not the complete outcome. The next proving action is to trace the first boundary after the changing state. Change only one condition before observing the result, and preserve timestamps or measurements where timing matters.

Review and recovery. The most common trap here is using the same value as command, status and independent feedback. After restoring the cause, repeat the normal case and at least one stop, timeout, disconnect or restart boundary relevant to this topic. Remove temporary forces and bypasses, return the model to a known state and retain the evidence that both operation and recovery are deliberate.

Explain it aloud: Why does a sortation count drift? A defensible short answer is: Common causes include level-based counting instead of edges, sensor bounce, duplicated writers, missing destination proof, manual product removal and unreconciled restart state.

Case 03

predict → observe → prove

Prove prove normal operation

Engineering context. normal products and divert products each receiving one decision and one confirmed destination without duplicated counts. Run more than one cycle from a known state and retain the values, timings or artifacts that demonstrate repeatability. Begin with a written normal condition and identify which request, state, physical result or communication value will provide independent confirmation. Do not begin by changing the configuration; the initial state is part of the evidence and should remain reproducible.

Controlled setup. Use the “Run the baseline” stage of the workflow: apply normal products and divert products each receiving one decision and one confirmed destination without duplicated counts from a clean start and record the expected evidence. The acceptance record should show this result: repeated runs produce the same bounded result. Record initial conditions, the exact stimulus and the observation point so another learner can repeat the case without relying on your memory.

Fault challenge. Introduce or analyse “Normal case passes but an edge case fails” as one bounded deviation. Inspect limits, timing, simultaneous events, reset and restart assumptions The working interpretation is that the implementation contains a hidden assumption exposed by the changed condition. The next proving action is to add the failed boundary as a permanent regression case. Change only one condition before observing the result, and preserve timestamps or measurements where timing matters.

Review and recovery. The most common trap here is changing several parameters before a baseline exists. After restoring the cause, repeat the normal case and at least one stop, timeout, disconnect or restart boundary relevant to this topic. Remove temporary forces and bypasses, return the model to a known state and retain the evidence that both operation and recovery are deliberate.

Explain it aloud: What should I learn first about sensor-triggered package classification, divert timing, confirmation and count reconciliation? A defensible short answer is: Start with the operating contract and evidence path: entry edge, product identity, class, conveyor state, travel delay, divert window, actuator feedback, destination sensor, counts and reject state, followed by sensor event through tracking record, time or position model, classification decision, output command, mechanism response and destination confirmation. Add advanced features only after the baseline is predictable.

Case 04

predict → observe → prove

Prove exercise a boundary case

Engineering context. sensor chatter, back-to-back products, missing class, late response, failed confirmation, jam, stop during transit, restart and manual removal. Choose minimum, maximum, simultaneous, delayed or restart conditions that reveal assumptions hidden by the happy path. Begin with a written normal condition and identify which request, state, physical result or communication value will provide independent confirmation. Do not begin by changing the configuration; the initial state is part of the evidence and should remain reproducible.

Controlled setup. Use the “Challenge assumptions” stage of the workflow: test sensor chatter, back-to-back products, missing class, late response, failed confirmation, jam, stop during transit, restart and manual removal without changing the acceptance contract. The acceptance record should show this result: limits, timing and restart behavior reach defined states. Record initial conditions, the exact stimulus and the observation point so another learner can repeat the case without relying on your memory.

Fault challenge. Introduce or analyse “The failure disappears after reset” as one bounded deviation. Inspect original symptom, histories, diagnostics, timestamps and active cause The working interpretation is that reset changed evidence or state without proving the initiating cause. The next proving action is to reproduce under a controlled condition and preserve pre/post-event data. Change only one condition before observing the result, and preserve timestamps or measurements where timing matters.

Review and recovery. The most common trap here is testing only one ideal sequence. After restoring the cause, repeat the normal case and at least one stop, timeout, disconnect or restart boundary relevant to this topic. Remove temporary forces and bypasses, return the model to a known state and retain the evidence that both operation and recovery are deliberate.

Explain it aloud: How do I practise sensor-triggered package classification, divert timing, confirmation and count reconciliation effectively? A defensible short answer is: Use short cases with known initial conditions, a written prediction, one action and an observable result. Then alter a boundary or fault and explain why the evidence changed.

Case 05

predict → observe → prove

Prove diagnose a controlled fault

Engineering context. an event, identity, classification, tracking, timing, output, actuator, destination, count or recovery mismatch. Preserve the first symptom, divide the system at a measurable boundary and change one condition only after predicting the result. Begin with a written normal condition and identify which request, state, physical result or communication value will provide independent confirmation. Do not begin by changing the configuration; the initial state is part of the evidence and should remain reproducible.

Controlled setup. Use the “Isolate one failure” stage of the workflow: introduce or analyse an event, identity, classification, tracking, timing, output, actuator, destination, count or recovery mismatch and locate the first disagreement. The acceptance record should show this result: the proving action distinguishes the leading hypotheses. Record initial conditions, the exact stimulus and the observation point so another learner can repeat the case without relying on your memory.

Fault challenge. Introduce or analyse “Simulator and target disagree” as one bounded deviation. Inspect model boundary, software version, task timing, I/O behavior, data types and configuration The working interpretation is that a learning model and the intended target do not share one of the recorded assumptions. The next proving action is to reduce the case and verify against current target documentation. Change only one condition before observing the result, and preserve timestamps or measurements where timing matters.

Review and recovery. The most common trap here is resetting, forcing or replacing before evidence is retained. After restoring the cause, repeat the normal case and at least one stop, timeout, disconnect or restart boundary relevant to this topic. Remove temporary forces and bypasses, return the model to a known state and retain the evidence that both operation and recovery are deliberate.

Explain it aloud: What counts as proof of competence? A defensible short answer is: A repeatable artifact or system result plus an explanation of the signal path is stronger than time spent, screenshots or a copied answer. Physical competence requires separate supervised evidence.

Case 06

predict → observe → prove

Prove transfer and hand over

Engineering context. the model compared with measured conveyor travel, actuator response, sensor placement and safe recovery on target equipment. Restore normal state, remove temporary changes, repeat affected checks and document which claims remain limited to the learning environment. Begin with a written normal condition and identify which request, state, physical result or communication value will provide independent confirmation. Do not begin by changing the configuration; the initial state is part of the evidence and should remain reproducible.

Controlled setup. Use the “Close the evidence loop” stage of the workflow: complete the model compared with measured conveyor travel, actuator response, sensor placement and safe recovery on target equipment and repeat the affected regression cases. The acceptance record should show this result: a run is complete only when the requested behavior, stop behavior, fault response and recovery are observable from a fresh initial condition. Record initial conditions, the exact stimulus and the observation point so another learner can repeat the case without relying on your memory.

Fault challenge. Introduce or analyse “The result cannot be explained” as one bounded deviation. Inspect prediction, observation, proving action, alternative hypotheses and limitations The working interpretation is that activity occurred but the evidence is not yet transferable or reviewable. The next proving action is to have the learner defend the signal path and repeat a changed case. Change only one condition before observing the result, and preserve timestamps or measurements where timing matters.

Review and recovery. The most common trap here is treating an acknowledged message or one successful rerun as handover. After restoring the cause, repeat the normal case and at least one stop, timeout, disconnect or restart boundary relevant to this topic. Remove temporary forces and bypasses, return the model to a known state and retain the evidence that both operation and recovery are deliberate.

Explain it aloud: Why test faults and restart behavior? A defensible short answer is: Because an event, identity, classification, tracking, timing, output, actuator, destination, count or recovery mismatch or sensor chatter, back-to-back products, missing class, late response, failed confirmation, jam, stop during transit, restart and manual removal can expose assumptions that never appear during ideal startup and steady operation.

Answer surface / 07

Questions people ask about PLC sortation diverter scenario

These concise answers define the operating, training and product boundaries most often missed in broad summaries. The full workflow and diagnostic table above provide the evidence behind them.

How do I time a PLC conveyor diverter?

Measure or model travel from the identification sensor to the diverter, retain the product decision and command inside a window that includes speed and actuator-response tolerances.

Why does a sortation count drift?

Common causes include level-based counting instead of edges, sensor bounce, duplicated writers, missing destination proof, manual product removal and unreconciled restart state.

What should I learn first about sensor-triggered package classification, divert timing, confirmation and count reconciliation?

Start with the operating contract and evidence path: entry edge, product identity, class, conveyor state, travel delay, divert window, actuator feedback, destination sensor, counts and reject state, followed by sensor event through tracking record, time or position model, classification decision, output command, mechanism response and destination confirmation. Add advanced features only after the baseline is predictable.

How do I practise sensor-triggered package classification, divert timing, confirmation and count reconciliation effectively?

Use short cases with known initial conditions, a written prediction, one action and an observable result. Then alter a boundary or fault and explain why the evidence changed.

What counts as proof of competence?

A repeatable artifact or system result plus an explanation of the signal path is stronger than time spent, screenshots or a copied answer. Physical competence requires separate supervised evidence.

Why test faults and restart behavior?

Because an event, identity, classification, tracking, timing, output, actuator, destination, count or recovery mismatch or sensor chatter, back-to-back products, missing class, late response, failed confirmation, jam, stop during transit, restart and manual removal can expose assumptions that never appear during ideal startup and steady operation.

Can browser practice replace official software or hardware?

No. It can build concepts and diagnostic reasoning. Exact firmware, I/O electrical behavior, networking, safety and commissioning require current official tools, documentation and target equipment.

How should progress be documented?

Keep the requirement, initial state, program or configuration, observed values, fault hypothesis, proving action, recovery result and a concise limitations statement.