PLC CODESYS - Advanced Software Structural Design | Using ST

Discover how global variables and IO global valuables provide a program-wide mapping between analog and digital inputs and outputs, enabling easy calibration, maintenance, and flexible signal swapping in ST.

Design an analog handler in ST that converts voltage or current signals to a physical value via gain scaling, producing a scaled value with upper and lower limits and warnings.

Design a motor driver block in ST that integrates start, overload, and emergency inputs with a feedback timer to validate coil activation and report status.

design a structured text proximity function block that handles any digital sensor by adding on time and off time delays to filter jitter and noise, yielding a detected output.

Perform a proximity sensor unit test in Codesys by instantiating the proximity function, wiring on-delay and off-delay timers, and simulating input signals to verify correct detect timing.

Introduces a product handler that moves product from the bunker to the mixer using dose control, weight tracking, and max/min limits via a structure text state machine.

Test and validate the product handler by instantiating the function, wiring inputs and outputs, and simulating weight targets, max limits, dosing logic, and state transitions.

Program the calibration board for the dozer by creating a duty, copying parameters, and configuring analog outputs and inputs with gain and limits using prefixes motor, bunker, weight, and way.

Design and implement data structures for read and send ports driven by analog and digital inputs and outputs, including initialization of the virtual control port with motor start.

Instantiate the analog output handler, route the controller-generated frequency through the virtual control board frequency scale, and apply calibrated gain and limits to drive the dozer speed controller.

instantiate the motor and connect the gate motor driver with digital inputs, fault injections, and motor start control, linking sources, sinks, and calibration timeout to enable safe motor operation.

Adapt the dozer frequency logic to the mixer, rename fault injection fields to frequency analog signal, and change the enable type from real to boolean before building the mixer frequency.

Instantiate the mixer timer by dragging a timer handler, wiring inputs and outputs, and using a virtual control board to start and read the mixer preset time from calibration.

Design and implement a mixer gate by building the gates driver, DFA blocks, and inputs and outputs for a virtual control board, including gate open sensor calibration and fault injection.

Create and instantiate global valuables across the Io and parameters folders for calibration, measurement, virtual control, and fault injection, centralizing communication and reading calibration through these assets.

Summarizes creating input/output module mapping in ST, linking each dozer and mixer signals to digital and analog inputs via global variables, and mapping outputs to their coils.

Perform integration testing of the doser system using the dozer component, refactoring test folders, fixing calibration timing, and validating fault injection, motor start, and emergency and overload scenarios.

Test the doser integration by injecting a real load into the load cell and converting the analog input to unsigned values, validating upper and lower limits up to 5000 kg.

Practice mixer integration testing in Codesys by configuring calibration, correcting unit timing from milliseconds to seconds, and validating fault injection, motor start, and emergency scenarios.

Perform integration testing of the mixer frequency control in CODESYS ST, validating frequency injection, analog handler conversion, and unsigned integer handling to achieve correct DAC output.

System test part 1 demonstrates testing after combining multiple components and connecting the control, addressing a bug in controller mapping, fault injection, and a new reset mechanism.