01
Логические значения TRUE и FALSE
Что означают TRUE и FALSE в PLC-программах и как они связаны с реальными сигналами.
Read lessonBack to learning catalog
Boolean logic
Logic values, operations, and truth tables
This track explains TRUE/FALSE conditions, why AND needs two active inputs, how OR differs from XOR, and how to move an expression into an FBD diagram.
What you learn
TRUE and FALSE describe condition state: button pressed, sensor active, permissive available.
AND, OR, NOT, and XOR combine simple conditions into expressions.
In FBD each operation becomes a block and connections show signal flow.
A truth table checks every input combination before running the diagram.
Track topics
TRUE / FALSEANDORNOTXORtruth tableslogic expressionspractical tasks
Related lessons
Logic lessons
02
Логическая операция AND
AND включает выход только при одновременном выполнении всех разрешающих условий.
Read lesson03
Логическая операция OR
OR объединяет несколько команд или условий, когда достаточно хотя бы одного активного сигнала.
Read lesson04
Логическая операция NOT
NOT инвертирует сигнал и помогает описывать запреты, аварии и активные низкие сигналы.
Read lesson05
Таблицы истинности
Как проверять поведение логических схем по всем сочетаниям входных сигналов.
Read lesson06
De Morgan's Laws in Logic Diagrams
Transform NOT, AND, and OR expressions, verify equivalence with a truth table, and apply De Morgan's laws in FBD.
Read lesson07
Binary Half Adder
Learn how XOR and AND add two one-bit binary numbers and produce the SUM and CARRY signals.
Read lessonPractice
Basic logic examples
Open an example, toggle inputs, and compare the output with the truth table.
Lamp from one button
A direct input-to-output connection shows the basic meaning of TRUE/FALSE.
Open exampleLamp from two buttons with AND
The lamp turns on only when both buttons are active.
Open exampleLamp from two conditions with OR
One active condition is enough to turn on the output.
Open exampleA AND NOT B
Permissive A works only while blocking condition B is not active.
Open exampleXOR as different states
The output is TRUE when two inputs are in different states.
Open example