Basic Codesys PLC programming in Structured Text

Write your first Codesys program using Structured Text and create a simple web visualization viewable in any browser.

Create a new Codesys project and write a simple structured text program for PLC, declaring a boolean lamp and two pushbuttons, then test the logic in online simulation.

Create your first visualization in codesys by adding a visualization manager, dragging lamp and push switches, and linking variables to elements for online simulation.

Modify the existing and gate to an or gate in the Codexis project, then add a push button with LED, a lamp, and labels, and position elements using the grid.

Master the basics of variables in Codesys PLC programming using structured text, exploring variables of different types to build your automation application.

Explore memory units in CODESYS PLC, from bits and bytes to words and double words, and learn how variables and constants are defined, addressed, and updated during programming.

Declare a boolean variable in Codesys with structured text, using Hungarian notation, set initial value false, and configure it as a local variable via the auto declare window.

Explore how integer data types work in 8, 16, and 32 bits, including signed and unsigned variants, with a 16-bit example and their value ranges.

Declare and manage integer variables across ranges such as integer, double integer, long integer, and unsigned short integer using prefixes. Explore overflow and switching to wider types while considering memory.

Declare byte and word variables in structured text and work with decimal, binary, octal, and hexadecimal constants, converting values with a calculator and switching notations in the PLC simulator.

Learn how to work with real floating point variables in structured text, declaring real values, understanding 32-bit and 64-bit representations, and applying them to physical measurements like temperature and pressure.

Learn to declare and use arrays in codices, with 0 to 10 indices, initialize values, access by index, and perform sums.

Define and use custom data types in the Codex project by creating a structure, declaring its variables, and accessing its fields in the program.

Define an enumeration data type for traffic lights in a codesys structured text project, assign yellow, green, and red as constants, and use the enumeration globally and as local variables.

Learn how to organize a plc project with program organization units, and distinguish local variables, which stay within a program, from global variables accessible project-wide; prefer local variables for readability.

Declare variables with types, assign today's date in decimal, binary, and octal, store day as string and temperature as floating point, and use a three-element array for calculation.

Master operators in Codesys PLC programming to perform arithmetic, logical operations, and value comparisons, enabling efficient code development.

Explore the assignment operator in codesys, comparing ladder language and structured text, showing the value from the button written to the lamp, negation, and move versus assignment with online simulation.

Explore how to perform addition, subtraction, multiplication, and division in Codesys, and manage variable types and type conversion to obtain integer or floating point results.

Master comparison operators in structured text, including greater than, greater or equal, less than, less or equal, equal, and not equal, returning bool values drive lamps in a PLC simulator.

Explore how expressions in plc programming in structured text are evaluated by operator binding, from parentheses to negation and comparisons, processed left to right, shaping results with an or gate.

Apply operators to code a Codesys PLC ventilator control in structured text, switching on/off by comparing set and actual temperatures using start, stop, and sensor inputs.

Explore essential control flow instructions in Codesys, including if else cases and the for loop, to manage program flow and efficiently repeat actions for dynamic automation applications.

Explore using if statements in structured text to control PLC program flow with bool inputs and incrementation, and understand the PLC cycle from input scan to output scan.

Learn how if, else if, and else conditions operate in structured text for Codesys PLC, using a debugger to step through PLC cycle, set breakpoints, and observe i counter behavior.

Explore how the case…of statement controls PLC outputs in structured text, using zero, one, and range conditions, with an else branch to switch off all lamps.

Explore how to implement a for loop in structured text for Codesys PLC, including initializing the counter, iterating from 0 to 9, and using a debugger to observe array values.

Explore Codesys structured text to build industrial automation projects, including a temperature controller for a control cabinet and a pumping station with three pumps, plus tips via the newsletter.