Basic
35 min

Brew Schedule Sequencer

brewingsequencingtemperatureprocess-controlmulti-phase

Ready to build this?

Sign up free — no credit card required. This scenario requires the Basic plan.

Sign up to play this scenario →

Already have an account? Log in

Brew Schedule Sequencer scenario preview

Briefing

A 4-phase brewing sequence controller. Phases: (1) Mash — heat to ~65°C for 60s, (2) Boil — heat to ~100°C for 45s, (3) Whirlpool — run pump for 20s, (4) Transfer — open valve for 15s. Each phase confirms readiness via temperature/flow feedback before timing out. Grain bin empty before mash start latches a pre-run fault.

Objectives

  • Grain bin must NOT be empty (GRAIN_BIN_EMPTY = FALSE) before mash phase starts
  • Phase 1 — Mash: MASH_HEATER on; MASH_TEMP_OK required within phase duration (60s)
  • Phase 2 — Boil: BOIL_HEATER on; BOIL_TEMP_OK required within phase duration (45s)
  • Phase 3 — Whirlpool: WHIRLPOOL_PUMP on for 20s
  • Phase 4 — Transfer: TRANSFER_VALVE on for 15s; FLOW_OK must assert
  • CYCLE_COMPLETE_LAMP pulses when transfer is done; GRAIN_BIN_EMPTY latches fault before mash

Hints

  • Use a PHASE INT (0=IDLE, 1=MASH, 2=BOIL, 3=WHIRLPOOL, 4=TRANSFER, 5=DONE)
  • Each phase has a TON timer; advance on timer expiry AND feedback condition met
  • GRAIN_BIN_EMPTY check: S= FAULT_BIT when GRAIN_BIN_EMPTY at mash start attempt
  • For testing, phase durations are compressed (mash=6s, boil=4.5s, whirlpool=2s, transfer=1.5s)

I/O Table

Inputs

START_PB

Start push-button

BOOL · %I0.0

STOP_PB

Stop / abort push-button

BOOL · %I0.1

MASH_TEMP_OK

Mash temperature at setpoint

BOOL · %I0.2

BOIL_TEMP_OK

Boil temperature at setpoint

BOOL · %I0.3

FLOW_OK

Flow sensor OK during transfer

BOOL · %I0.4

GRAIN_BIN_EMPTY

Grain bin empty sensor

BOOL · %I0.5

Outputs

MASH_HEATER

Mash vessel heater

BOOL · %Q0.0

BOIL_HEATER

Boil kettle heater

BOOL · %Q0.1

WHIRLPOOL_PUMP

Whirlpool pump

BOOL · %Q0.2

TRANSFER_VALVE

Transfer valve

BOOL · %Q0.3

CYCLE_COMPLETE_LAMP

Brew cycle complete lamp

BOOL · %Q0.4

Your program will be tested against:

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

  1. #1GRAIN_BIN_EMPTY blocks mash start

    If grain bin is empty when START_PB pressed, fault latches and mash does not start

  2. #2MASH_HEATER on during mash phase

    After a valid start, MASH_HEATER asserts during phase 1

  3. #3Full 4-phase brew cycle completes

    Physics provides all feedback signals; CYCLE_COMPLETE_LAMP asserts at end

  4. #4STOP_PB aborts cycle mid-phase

    Pressing STOP_PB during any phase halts all outputs

Ready to build this?

Sign up free — no credit card required. This scenario requires the Basic plan.

Sign up to play this scenario →

Already have an account? Log in

Runnable simulator field guide

Brew schedule PLC sequencer scenario: test checklist

Direct answer

The learner can separate schedule intent from current batch state, advance only on proven transition conditions and recover an interrupted batch without guessing material state.

Written for pLC and process-control learners sequencing recipe steps across vessels, pumps, valves, temperatures and durations.

a water-based process skid with vessel, flow transmitter, control valve, pump and observable batch response while studying batch schedule state, equipment allocation, transition proof and interrupted-batch recovery
System map / 02

NODE 01observable

Scenario setup

Batch identity, recipe version, scheduled start, unit availability, material state, step, command, feedback, transition condition, hold and completion record.

NODE 02observable

I/O and state map

Schedule request through batch state and equipment arbitration into valve, pump or temperature commands, physical model feedback and recorded transition evidence.

NODE 03observable

Normal run

One declared recipe advancing through charge, heat, hold, transfer and completion with each transition caused by observable conditions.

NODE 04observable

Boundary run

Late start, unavailable unit, temperature timeout, valve feedback loss, pause, operator hold, restart, schedule conflict and partially transferred material.

NODE 05observable

Injected fault

A schedule, identity, recipe, unit allocation, step, command, equipment, feedback, transition or recovery mismatch.

NODE 06observable

Target check

The control model transferred only after recipe governance, process hazards, equipment limits, records and target-platform behavior are reviewed.

Answer surface / 07

What is the difference between a brew schedule and a PLC sequence?

The schedule says when and which batch should run; the sequence owns the current step and equipment actions. Joining them requires identity, availability and conflict rules.

How should a batch recover after a PLC restart?

Reconcile retained software state with actual vessel contents, temperatures, valve positions and equipment status, then use an approved hold, resume or abort procedure.