Elementary Data Types according to IEC 61131-3

Data type

Size in bits

Range

Default initial value

BOOL

Boolean

TRUE / FALSE

FALSE

SINT

Short integer

-128 to 127

INT

Integer

-32,768 to 32,767

DINT

Double integer

-2,147,483,648 to 2,147,483,647

LINT

Long integer

-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807

USINT

Unsigned short integer

0 to 255

UINT

Unsigned integer

0 to 65,535

UDINT

Unsigned double integer

0 to 4,294,967,295

ULINT

Unsigned long integer

0 to 18,446,744,073,709,551,615

REAL

Real numbers

-3.402823466 E+38 (approx. 7 digits)
to
-1.175494351 E-38 (approx. 7 digits)

and

+1.175494351 E-38 (approx. 7 digits)
to
+3.402823466 E+38 (approx. 7 digits)

See the note below the table concerning REAL and LREAL processing.

0.0

LREAL

Long real numbers

~ -1.798 E+308 (approx. 15 digits)
to
~ -2.225 E-308 (approx. 15 digits)

and

~ +2.225 E-308 (approx. 15 digits)
to
~ +1.798 E+308 (approx. 15 digits)

See the note below the table concerning REAL and LREAL processing.

0.0

TIME

Duration

-24d20h31m23s648ms up to 24d20h31m23s647ms

t#0s

LTIME

Long duration

- 106751d23h47m16s854ms775us808ns up to +106751d23h47m16s854ms775us807ns

LTIME#0ns

BYTE

Bit string of length 8

0 to 255
(16#00...16#FF)

WORD

Bit string of length 16

0 to 65,535
(16#00...16#FFFF)

DWORD

Bit string of length 32

0 to 4,294,967,295
(16#00....16#FFFFFFFF)

LWORD

Bit string of length 64

0 to 18,446,744,073,709,551,615
(16#00....16#FFFFFFFFFFFFFFFF)

LDATE / LD

Long date

min. : 1677-09 -22

max. : 2262-04-11

LDATE#1970-01-01

LTIME_OF_DAY / LTOD

Long time of day

min. : 00:00:00.0

max. : 23:59:59.999999999

See the note below the table concerning LTOD processing.

Note
Although an LTOD value can be calculated with microseconds, nanoseconds parts, the online display is limited to 4 digits.
Only the ms part and 100µs resolution is shown (4 digits; xxx.000_0).

LTOD#00:00:00

LDATE_AND_TIME / LDT

Long date with time of day

min. : 1677-09-21-00:12:43.145224192

max. : 2262-04-11-23:47:16.854775807

Note
Although an LDT value can be calculated with microseconds, nanoseconds parts, the online display is limited to 4 digits.
Only the ms part and 100µs resolution is shown (4 digits; xxx.000_0).

LDT#1970-01-01-00:00:00

Note
If you are using iCube Engineer in another user interface language and/or with another Windows system locale than English you must enter numeric values with a '.' as decimal separator (always according to the English standard). This applies, for example, when entering initial values in variables tables or REAL/LREAL literals in the code.

Note
Processing of REAL and LREAL data types
There is a limited accuracy when processing REAL and LREAL data types. This is caused by the characteristics of the processor architecture and the data type definition according to IEEE. This applies to the positive and also the negative value range.

Note
Processing of LTOD data type
In the event of an overflow (min or max value for the LTOD data type exceeded), the LTOD value is interpreted and displayed as time value in nanoseconds ("xxxxx ns").

Data types STRING and WSTRING
The data types STRING (single byte string) and WSTRING (double byte string) are also elementary data types but do not belong to the above mentioned group. The data types STRING and WSTRING have the following structure:

Byte	Description
STRING data type
0...1	Capacity - Maximum number of characters that the string can hold (from 0 to UINT16.MAX).
2...3	Length - Current number of characters in the string (from 0 to Capacity).
4...84 (for an 80 characters string) 4...124 (for a user-defined string of 120 characters)	String of ANSI characters followed by a trailing zero character. Each character is represented by one byte.
WSTRING data type
0-1	Capacity - Maximum number of characters that the string can hold (from 0 to UINT16.MAX).
2-3	Length - Current number of characters in the string (from 0 to Capacity).
4...165 (for an 80 characters string) 4...245 (for a user-defined string of 120 characters)	String of UTF16 characters followed by a trailling zero character. Each character is represented by two bytes or, for some language characters, by four bytes.