Instructional Process Engineering Labs
Select a guided scenario to auto-configure field devices, load ladder logic templates, and practice real-world automation routines.
Motor Three-Wire Seal-In Circuit (Start/Stop)
Learn how to construct standard industrial latching (seal-in) logic using discrete Normally Open (Start) and Normally Closed (Stop) pushbuttons, implemented here with Set/Reset latching coils, to safely energize and hold a motor starter relay.
Automated Level Control with Hysteresis
Process tank control using an Analog Level Sensor (4-20mA). Two compare blocks set the fill valve on below 25% and reset it off above 85%, so the pump doesn't chatter on and off right at one threshold.
Timed Conveyor Bottle Filling Line
Design a sequential state machine. Proximity switch detects bottle -> Conveyor stops -> Valve opens for 3-second fill timer -> Conveyor resumes -> Counter increments batch tally.
Batch Heating & Agitation Loop
Integrated temperature control. Uses Analog Temp Sensor (RTD/TC) and Modulating Heater Output (AO:0) with timed mixer agitation sequence and safety high-temp interlocks.
Signal Trend Scope & Memory Inspector
Real-time trace visualizer for digital switching waveforms and analog 4-20mA / 0-10V loop currents.
PLC Memory Table & Data Registers
Process Engineering & PLC Fundamentals
Subject Matter Expert (SME) Curriculum Guide
A Programmable Logic Controller (PLC) is an industrial digital computer designed for ruggedized operational technology (OT) applications. PLCs continuously monitor field inputs (sensors, switches, transmitters), execute custom program logic stored in memory, and control field outputs (motors, valves, heaters, alarms) to automate industrial processes.
Discrete signals exist in binary states: ON (1 / HIGH / 24VDC) or OFF (0 / LOW / 0VDC).
- Pushbuttons: NO (Normally Open) or NC (Normally Closed)
- Limit Switches: Physical object position detection
- Solenoid Valves: Open / Close directional control
- Motor Starters: Run / Stop contactors
Analog signals represent continuous physical variables (e.g., Temperature, Pressure, Flow, Level) mapped across standardized electrical ranges.
- Current Loop: 4 - 20 mA (Industry standard; offers live zero detection)
- Voltage Signal: 0 - 10 VDC
- Modulating Control: Control Valve 0-100% opening
- VFD Speed: Motor speed command 0-60 Hz
The Three-Step PLC Scan Cycle
The PLC copies physical signal states from input screw terminals into the Input Image Table memory area.
The CPU solves ladder rungs sequentially from top to bottom, left to right, evaluating Boolean conditions and math blocks.
Evaluated states in the Output Image Table are written to physical output relays and analog channels simultaneously.