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BAS ACADEMY
WEEK 10 Stage 2 · Hands-on lab 10 hours

Industrial Controls: PLC and Modbus

DELIVERABLE Booster/lift-station PLC logic

Week progress0%
Level 10 badge: PLC Ladder

Learning objectives

  • >Write basic ladder logic with contacts, coils, timers and counters
  • >Program duplex alternation and alarms for a booster or lift station
  • >Read and write Modbus registers from Python
  • >Compare industrial SCADA with commercial BAS

Sessions

Three 2-hour weeknight sessions plus a weekend block. Check each one off as you finish it.

Quiz

Score: 0 / 5 · aim for 4+

Answer in your notebook first, then reveal the answer and grade yourself honestly.

  1. Q1What is the difference between a normally open and a normally closed contact in ladder logic?

    [ reveal answer ]
    A normally open contact passes power when its bit is true. A normally closed contact passes power when its bit is false.

  2. Q2What does a TON timer do?

    [ reveal answer ]
    It's an on-delay timer: its output turns on after the input has been true for the preset time.

  3. Q3In classic Modbus notation, what does address 40001 refer to?

    [ reveal answer ]
    Holding register 1 (protocol offset 0).

  4. Q4Give two differences between wastewater SCADA and a hospital BAS.

    [ reveal answer ]
    Examples: SCADA has stricter redundancy and regulatory requirements, 24/7 operators, historian and reporting duties, and protocols such as DNP3. A hospital BAS focuses on comfort, pressurization and energy.

  5. Q5What does an alternator do in a duplex lift station?

    [ reveal answer ]
    It swaps the lead pump each cycle and brings the lag pump on at high level.

// DONE WHEN

// STRETCH (OPTIONAL)

OpenPLC Editor.