PLC Data Type in TIA Portal

 In TIA Portal (Totally Integrated Automation Portal), the programming environment for Siemens PLCs, there are several data types you can use when creating variables, tags, or defining the structure of your program. The data types specify what kind of data can be stored in a variable or tag and how it can be processed.

Here are the main PLC data types in TIA Portal:

1. Bool (Boolean)

• Description: Represents a binary state, either TRUE (1) or FALSE (0).
• Typical Usage: Used for flags, conditions, or inputs/outputs like switches and sensors.
• Example: LightStatus BOOL

2. Byte

• Description: Represents an 8-bit value ranging from 0 to 255 (unsigned) or -128 to 127 (signed).
• Typical Usage: Used for small integers or byte-wise data.
• Example: TemperatureByte BYTE

3. Word

• Description: Represents a 16-bit value, typically ranging from 0 to 65535 (unsigned) or -32768 to 32767 (signed).
• Typical Usage: Used for integer values in a range of 16-bit.
• Example: Speed WORD

4. DWord (Double Word)

• Description: Represents a 32-bit value, typically ranging from 0 to 4,294,967,295 (unsigned) or -2,147,483,648 to 2,147,483,647 (signed).
• Typical Usage: Used for larger integer values or time-related data (e.g., milliseconds).
• Example: Counter DWord

5. Real

• Description: Represents a 32-bit floating-point value for real numbers with decimal points.
• Typical Usage: Used for measurements or calculations involving fractions.
• Example: TemperatureReal REAL

6. String

• Description: Represents a sequence of characters (text). The length of the string is defined by the user.
• Typical Usage: Used to store text, messages, or labels.
• Example: Message STRING[20]

7. Int (Integer)

• Description: Represents a 16-bit signed integer, with values ranging from -32,768 to 32,767.
• Typical Usage: Used for counting or integer values within the 16-bit range.
• Example: StepNumber INT

8. DInt (Double Integer)

• Description: Represents a 32-bit signed integer, with values ranging from -2,147,483,648 to 2,147,483,647.
• Typical Usage: Used for large integers.
• Example: TotalCount DInt

9. Time

• Description: Used to store time data, expressed in various units like milliseconds, seconds, etc.
• Typical Usage: Used for timers or delays.
• Example: DelayTime TIME

10. Time of Day (TOD)

• Description: Stores the current time of day (HH:MM:SS format).
• Typical Usage: Used to store the current system time.
• Example: CurrentTime TOD

11. Date

• Description: Stores a specific date (YYYY-MM-DD format).
• Typical Usage: Used for date-related information, like logging or scheduling.
• Example: StartDate DATE

12. Date and Time (DT)

• Description: Stores both date and time information in one variable (YYYY-MM-DD HH:MM:SS format).
• Typical Usage: Used for time-stamped data or events.
• Example: LogTimestamp DT

13. Array

• Description: An array is a collection of variables of the same data type, indexed by a numerical value.
• Typical Usage: Used for storing sequences of related data.
• Example: TemperatureArray[10] REAL

14. Structure (Struct)

• Description: A custom data type that combines multiple different data types under one variable. The structure can contain other basic types like BOOL, INT, REAL, etc.
• Typical Usage: Used for organizing complex data into logical groupings.
• Example:

  TYPE MotorStatus :
      STRUCT
          Running : BOOL;
          Speed : REAL;
          Temperature : REAL;
      END_STRUCT;
  END_TYPE
  

15. Pointer

• Description: A pointer stores the address of another variable or data location. This data type is often used in advanced programming.
• Typical Usage: Used for indirect addressing in data manipulation or for more complex memory management tasks.

16. Union

• Description: A data type that allows multiple variables to share the same memory location but store different types of data. It helps to reduce memory usage in some cases.
• Typical Usage: Used in specific applications where different types of data might be interpreted in the same memory space.

Special Data Types in TIA Portal:

• IEC Data Types: These are predefined data types that comply with IEC 61131-3 standards. For example:
  • SINT (Short Integer): 8-bit signed integer.
  • USINT (Unsigned Short Integer): 8-bit unsigned integer.
  • INT (Integer): 16-bit signed integer.
  • DINT (Double Integer): 32-bit signed integer.
  • LINT (Long Integer): 64-bit signed integer.
  • REAL: 32-bit floating-point.
  • STRING: Sequence of characters.

How to Define and Use Data Types in TIA Portal:

1. Create Variable: In your project, under the "PLC" tab, go to "Variables" or "Global Data Blocks". You can create new variables and assign them the appropriate data type.
2. Use in Logic: In your function blocks (FB), functions (FC), or ladder logic (LAD), use the defined variables by referencing their data type. For example:

   VAR
       MotorSpeed : REAL;
       ConveyorStatus : BOOL;
   END_VAR
   

3. Tag Names: The names you define for the variables can also be used as "tags" in HMI or SCADA systems to interact with the PLC.

Summary:

• Basic Types: BOOL, BYTE, WORD, DWord, Int, Real, etc.
• Time Types: TIME, TOD, DT.
• Complex Types: Arrays, Structures, Unions.

By understanding and using these data types, you can design more efficient and effective PLC programs in TIA Portal.