Attention

IronPLC supports IEC 61131-3 Structured Text excluding I/O mapping.

Functions¶

IEC 61131-3 defines a set of standard functions available in all programming languages. Functions are stateless — they produce the same output for the same inputs every time.

Numeric Functions¶

Function	Description
ABS	Absolute value
SQRT	Square root
LN	Natural logarithm
LOG	Base-10 logarithm
EXP	Natural exponential
EXPT	Exponentiation
TRUNC	Truncate real to integer

Trigonometric Functions¶

Function	Description
SIN	Sine
COS	Cosine
TAN	Tangent
ASIN	Arc sine
ACOS	Arc cosine
ATAN	Arc tangent

Arithmetic Functions¶

Function	Description
ADD	Addition
SUB	Subtraction
MUL	Multiplication
DIV	Division
MOD	Modulo

Comparison Functions¶

Function	Description
GT	Greater than
GE	Greater than or equal
EQ	Equal
LE	Less than or equal
LT	Less than
NE	Not equal

Assignment Functions¶

Function	Description
MOVE	Assignment (copy value)

Selection Functions¶

Function	Description
SEL	Binary selection
MAX	Maximum
MIN	Minimum
LIMIT	Clamp to range
MUX	Multiplexer

Bit String Functions¶

Function	Description
SHL	Shift left
SHR	Shift right
ROL	Rotate left
ROR	Rotate right

String Functions¶

Function	Description
LEN	String length
LEFT	Left substring
RIGHT	Right substring
MID	Middle substring
CONCAT	String concatenation
INSERT	String insertion
DELETE	String deletion
REPLACE	String replacement
FIND	String search

Time and Date Functions¶

Function	Description
ADD_TIME	Add two durations
SUB_TIME	Subtract durations
MUL_TIME	Scale duration by number
DIV_TIME	Divide duration by number
ADD_DT_TIME	Add duration to date-and-time
ADD_TOD_TIME	Add duration to time-of-day
SUB_DT_TIME	Subtract duration from date-and-time
SUB_TOD_TIME	Subtract duration from time-of-day
SUB_DT_DT	Difference between two datetimes
SUB_DATE_DATE	Difference between two dates
SUB_TOD_TOD	Difference between two times-of-day
CONCAT_DATE_TOD	Combine date and time-of-day
DT_TO_DATE	Extract date from datetime
DT_TO_TOD	Extract time-of-day from datetime

Type Conversion Functions¶

Function	Description
Type conversions	Type conversion functions (`_TO_`)
BCD_TO_INT / INT_TO_BCD	BCD conversion functions