ST Supported Datatypes Coming Soon

This section lists all the supported IEC 61131-3 Structured Text datatypes.

Standard Datatypes

Name	Size	Properties
BOOL	8 bit	Signed
BYTE	8 bit	Unsigned
WORD	16 bit	Unsigned
DWORD	32 bit	Unsigned
LWORD	64 bit	unsigned
SINT	8 bit	Signed
USINT	8 bit	Unsigned
INT	16 bit	Signed
UINT	16 bit	Unsigned
DINT	32 bit	Signed
UDINT	32 bit	Unsigned
LINT	64 bit	Signed
ULINT	64 bit	Unsigned
REAL	32 bit	Float
LREAL	64 bit	Float
__VOID	Undefined

Declaration examples

A := BOOL#0
A := TRUE
A := UNIT#2
A := abc=USINT#16#FFFF

Strings

Name	Size	Encoding
STRING	n+1	UTF-8
WSTRING	2n+2	UTF-16

String simple examples

A : STRING;
A : STRING[10];
A : WSTRING := 'Hello World';
A : STRING[20] := 'Hello World';

Date & Time

Name	Size	Internally stored as
TIME	64 bit	Timespan in nanoseconds
TIME_OF_DAY	64 bit	Nanoseconds since Jan 1, 1970 UTC
DATE	64 bit	Nanoseconds since Jan 1, 1970 UTC
DATE_AND_TIME	64 bit	Nanoseconds since Jan 1, 1970 UTC

Date examples

A : DATE := DATE#2024-04-02;
A : DATE := DATE#1-12-24;
A : DATE := D#2024-1-1;

Date & Time examples

A : DATE_AND_TIME := DATE_AND_TIME#2024-05-02-14:20:10.25;
A : DATE_AND_TIME := DATE_AND_TIME#1-11-24-00:00:1;
A : DATE_AND_TIME := DT#2024-11-1-23:59:59.999;

Time Of Day examples

A : TIME_OF_DAY := TIME_OF_DAY#15:06:3.35;
A : TIME_OF_DAY := TIME_OF_DY#1:00:1;
A : TIME_OF_DAY := TOD#23:59:59.999;

Time examples

A : TIME := TIME#4d1h8m8s11ms;
A : TIME := T#3d4.4h;
A : TIME := T#-11s3ms23ns;

Structure type supported

Example

TYPE ANALOG_CHANNEL_CONFIGURATION :
    STRUCT
        RANGE : ANALOG_SIGNAL_RANGE ; MIN_SCALE : ANALOG_DATA ; MAX_SCALE : ANALOG_DATA;
    END_STRUCT; 
ANALOG_16_INPUT_CONFIGURATION :
    STRUCT
        SIGNAL_TYPE : ANALOG_SIGNAL_TYPE;
        FILTER_PARAMETER : SINT (0..99);
        CHANNEL : ARRAY [1..16] OF ANALOG_CHANNEL_CONFIGURATION;
    END_STRUCT ; 
END_TYPE

Enumerated type

Example

TYPE 
    ANALOG_SIGNAL_TYPE : (SINGLE_ENDED, DIFFERENTIAL); 
END_TYPE

Sub-range type

Example

TYPE 
    ANALOG_DATA : INT (-4095..4095); 
END_TYPE

Array type

Example

TYPE ANALOG_16_INPUT_DATA : 
    ARRAY [1..16] OF ANALOG_DATA; 
END_TYPE