The following strings are reserved as keywords, i.e. they cannot be used as identifiers for variables or POUs:

 

ABS⮫ “ABS”

ACOS ⮫ “ACOS”

ACTION (only used in the Export Format)

ADD⮫ “ADD”

ADR⮫ “ADR”

ADRINST ⮫ “ADRINST”

AND ⮫ “AND”

ANDN

ARRAY⮫ “ARRAY”

ASIN⮫ “ASIN”

AT⮫ “Address”

ATAN⮫ “ATAN”

BITADR⮫ “BITADR”

BOOL⮫ “BOOL”

BY⮫ “FOR loop”

BYTE⮫ “Integer data types”

CAL  

CALC

CALCN

CASE ⮫ “CASE instruction”

CONSTANT⮫ “Constants, typed literals”

COS⮫ “COS” 

DATE ⮫ “Time data types”

DINT ⮫ “Integer data types”

DIV⮫ “DIV”

DO⮫ “FOR loop”

DT⮫ “Time data types”

DWORD⮫ “Integer data types”

ELSE⮫ “IF instruction”

ELSEIF⮫ “IF instruction”

END_ACTION (only used in the Export Format)

END_CASE⮫ “CASE instruction”

END_FOR ⮫ “FOR loop”

END_FUNCTION (only used in the Export Format)

END_FUNCTION_BLOCK (only used in the Export Format)

END_IF⮫ “IF instruction”

END_PROGRAM (only used in the Export Format)

END_REPEAT⮫ “REPEAT loop”

END_STRUCT⮫ “Structures”

END_TYPE⮫ “Enumeration”

END_VAR ⮫ “Local variables”

END_WHILE⮫ “WHILE loop”

EQ ⮫ “EQ”

EXIT ⮫ “EXIT instruction”

EXP⮫ “EXP”

EXPT⮫ “EXPT”

FALSE⮫ “BOOL”

FOR⮫ “FOR loop”

FUNCTION ⮫ “Function”

FUNCTION_BLOCK⮫ “Function block”

GE⮫ “GE”

GT⮫ “GT”

IF⮫ “IF instruction”

INDEXOF⮫ “INDEXOF”

INI⮫ “INI operator”

INT⮫ “Integer data types”

JMP

JMPC

JMPCN

LD

LDN

LE ⮫ “LE”

LINT ⮫ “Integer data types”

LN ⮫ “LN”

LOG ⮫ “LOG”

LREAL ⮫ “REAL / LREAL”

LT ⮫ “LT”

LWORD⮫ “Integer data types”

MAX⮫ “MAX”

MIN ⮫ “MIN”

MOD ⮫ “MOD”

MOVE⮫ “MOVE”

MUL⮫ “MUL”

MUX⮫ “MUX”

NE⮫ “NE”

NOT⮫ “NOT”

OF⮫ “ARRAY”

OR ⮫ “OR”

ORN

PERSISTENT

POINTER⮫ “Pointer”

PROGRAM ⮫ “Program”

R

READ_ONLY

READ_WRITE

REAL ⮫ “REAL / LREAL”

REPEAT⮫ “REPEAT loop”

RET

RETAIN

RETC

RETCN

RETURN⮫ “RETURN instruction”

ROL⮫ “ROL”

ROR⮫ “ROR”

S

SEL⮫ “SEL”

SHL ⮫ “SHL”

SHR⮫ “SHR”

SIN⮫ “SIN”

SINT ⮫ “Integer data types”

SIZEOF⮫ “SIZEOF”

SQRT⮫ “SQRT”

ST

STN

STRING⮫ “STRING”

STRUCT⮫ “Structures”

SUB⮫ “SUB”

TAN ⮫ “TAN”

THEN⮫ “IF instruction”

TIME⮫ “Time data types”

TO ⮫ “FOR loop”

TOD⮫ “Time data types”                 

TRUE⮫ “BOOL”

TRUNC⮫ “TRUNC”

TYPE⮫ “Enumeration”

UDINT⮫ “Integer data types”

UINT⮫ “Integer data types”

ULINT ⮫ “Integer data types”

UNTIL⮫ “REPEAT loop”

USINT⮫ “Integer data types”

VAR⮫ “Local variables”

VAR_ACCESS (only used very specifically, depending on the hardware)

VAR_CONFIG⮫ “Overview”

VAR_CONSTANT⮫ “Constants, typed literals”

VAR_EXTERNAL ⮫ “External variables”

VAR_GLOBAL⮫ “Several variables lists”

VAR_IN_OUT⮫ “Input and output variables”

VAR_INPUT⮫ “Input variable”

VAR_OUTPUT ⮫ “Output variable”

WHILE ⮫ “WHILE loop”

WORD⮫ “Integer data types”

WSTRING (IEC data type is not supported)

XOR⮫ “XOR”

XORN

Additionally all conversion operators as listed in the 'Edit' 'Input assistant' are handled as keywords⮫ “'Edit' 'Input assistant'”.