Mitsubishi MELSEC-q Programming Manual page 26

3 HANDLING OF CHARACTERS AND NUMERIC VALUES IN ST PROGRAMS
3
3 - 2
(2) Character types
The characters used in ST programs can be classified as indicated below.
Classification
Label name
Constant
Comment
Data type
name
Control
syntax
Reserved
word
Device
name
Function
name
Operator
Delimiter
Other symbols
Description
Character string defined as
desired by the user.
It includes a function block
name, array name, structure
name, etc.
Value written directly to a
program.
(Integer, real number,
character string, etc.)
Commentary statement that
is not the processing target
of control in a program.
Word that represents a data
type.
Word whose meaning has
been defined grammatically
for use as a control syntax.
Data name for MELSEC
PLC
MELSEC function/IEC
function name already
defined.
Character code whose
meaning has been defined
for an expression or
assignment statement.
Character code whose
meaning has been defined to
clarify a program structure.
Code for putting a layout in
order.
Example
Switch_A
123, "abc"
(* Turns ON *)
BOOL, DWORD
IF, CASE, WHILE, RETURN
X, Y, M, ZR
OUT_M
REAL_TO_STR_E
+ - < > =
; ( )
Space
Line feed code, TAB
3 - 2