Chapter 4 Variable
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[Description of Dialog Box]
a. Variable kind: VAR, VAR_CONSTANT, VAR_INPUT, VAR_OUTPUT, VAR_IN_OUT, VAR_EXTERNAL and
VAR_EXTERNAL_CONSTANT are available.
- If a variable type is CONSTANT, the initial value is set as the default.
- VAR_INPUT, VAR_OUTPUT and VAR_IN_OUT can not set the initial value.
b. Variable name: The declared variable can not be duplicated with the identical name.
- A figure is unavailable for the first character.
- A special character is unavailable. (However,‘_’ is available.)
- Space is not available as a character.
- A same name with a direct variable is unavailable(i.e. MB4, W4, RW9,…)
-If a line is empty, BOOL is displayed as the default type when entering a variable.
c. Type: 23 types are available; 20 basic types and 3 induced types.
- Basic type(20): (BOOL, BYTE, WORD, DWORD, LWORD, SINT, INT, DINT, LINT, USINT, UINT, UDINT,
ULINT, REAL, LREAL, TIME, DATE, TIME_OF_DAY, DATE_AND_TIME, STRING)
- Induced type(3): ARRAY(예, ARRAY[0..6,0..2,0..4] OF BOOL) => factor limit (up to 3rd), STRUCT(i.e.
STRUCT name display) => STRUCT type is not available in STRUCT(i.e. FB name
display)
d. Trigger: it is VAR_INPUT or VAR_IN_OUT and active only in BOOL type; it can set R and F status.
e. Memory address: it can not be declared as Read Only.
f. Initial Value: it can be set.
- Initial value can not be set if the variable type is VAR_INPUT, VAR_OUTPUT or VAR_IN_OUT.
g. Retain: it can not be declared as Read Only.
h. Used: it can not be declared as Read Only.
i. Comment: every character is available.
- Multi line entry is available by using Ctrl + Enter key.
j. Line validity: To register on global variable window, it needs variable type, variable and type.
- If not registered on global variable, it displays in pink.
Notes
- If any error occurs when editing a cell, it is displayed in pink.
- Press ESC key to recover the previous value during the cell edit.
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