====== Elementary Data Types (BOOL, INT, REAL, STRING, etc.) ======

The EN 61131-3 defines the basic set of data types listed in the table below, including keywords, bit length, range, and initial value.

^Keyword                    ^Type                                    ^Bits^Range                                                                                         ^Initial value         ^
|BOOL                       |Boolean number                          |1   |0, 1                                                                                          |0                     |
|SINT                       |Short integer                           |8   |-128 to 127                                                                                   |0                     |
|INT                        |Integer                                 |16  |-32768 to 32767                                                                               |0                     |
|DINT                       |Integer, double length                  |32  |-2 147 483 648 to 2 147 483 647                                                               |0                     |
|LINT                       |Long integer                            |64  |-9223372036854775808 to 9223372036854775807                                                   |0                     |
|USINT                      |Unsigned short integer                  |8   |0 to 255                                                                                      |0                     |
|UINT                       |Unsigned integer                        |16  |0 to 65535                                                                                    |0                     |
|UDINT                      |Unsigned integer, double length         |32  |0 to 4294967295                                                                               |0                     |
|ULINT                      |Unsigned long integer                   |64  |0 to 18446744073709551615                                                                     |0                     |
|REAL                       |Floating point number (single precision)|32  |-3.40282347E+38 to 3.40282347E+38 (closest to zero is 1.401298E-45)                           |0.0                   |
|LREAL                      |Floating point number (double precision)|64  |-1.7976931348623157E+308 to 1.7976931348623157E+308 (closest to zero is 4.94065645841247E-324)|0.0                   |
|TIME                       |Time period duration                    |64  |-                                                                                             |T#0s (Note 1)         |
|LTIME                      |Time period duration                    |64  |units: ns                                                                                     |T#0s (Note 1)         |
|DATE                       |Date                                    |64  |-                                                                                             |1.1.1970 00:00:00     |
|LDATE                      |Date                                    |64  |units: ns since 1.1. 1970                                                                     |LDATE#1970-01-01      |
|TIME_OF_DAY (short: TOD)   |Time in a day                           |64  |-                                                                                             |TOD#00:00:00          |
|LTIME_OF_DAY (short: LTOD) |Time in a day                           |64  |units: ns since 1.1. 1970                                                                     |LTOD#00:00:00         |
|DATE_AND_TIME (short: DT)  |Absolute time                           |64  |-                                                                                             |-                     |
|LDATE_AND_TIME (short: LDT)|Absolute time                           |64  |units: ns since 1.1. 1970                                                                     |LDT1970-01-01-00:00:00|
|STRING                     |String of characters                    |16  |max. 255 characters                                                                           |'' (empty string)     |
|BYTE                       |Sequence of 8 bits                      |8   |16#FF                                                                                         |16#00                 |
|WORD                       |Sequence of 16 bits                     |16  |16#FFFF                                                                                       |16#0000               |
|DWORD                      |Sequence of 32 bits                     |32  |16#FFFFFFFF                                                                                   |16#00000000           |
|LWORD                      |Sequence of 64 bits                     |64  |16#FFFFFFFFFFFFFFFF                                                                           |16#0000000000000000   |

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Note 1: Format of time is as follows: T# and numeric value in days (d), hours (h), minutes (m), seconds (s), and milliseconds (ms). The units can be combined. Examples: T#1h, T#20m, T#1h10m7s, T#15m1s = T#901s, T#1500ms = T#1s500ms.