Omron CX-PROGRAMMER V8.1, Руководство по эксплуатации

Страница: 184 / 231

159
Statement Descriptions
Section 5-5
• Statements that can be used in the expression are assignment state-
ments, IF, CASE, FOR, WHILE, or REPEAT.
• Multiple statements can be executed in the expression . Be sure to use a
semicolon (;) delimiter between multiple statements in an expression .
• The condition can also be specified as a boolean variable (BOOL data
type) only rather than an equation.
■
Examples
Example 1: Numeric values from 1 through 10 are incremented and the total
is substituted for the variable TOTAL.
A:=1;
TOTAL:=0;
REPEAT
TOTAL:=TOTAL+A;
A:=A+1;
UNTIL A>10
END_REPEAT;
EXIT Statement
■
Summary
This statement is used within iteration statements (FOR, WHILE, REPEAT)
only to force an iteration statement to end. This statement can also be used
within an IF statement to force an iteration statement to end when a specified
condition is met.
■
Reserved Words
EXIT
■
Statement Syntax (Example: Using within IF Statement)
FOR (WHILE, REPEAT)
expression
...
IF
< condition >
THEN EXIT;
END_IF;
...
END_FOR (WHILE, REPEAT);
■
Usage
Use the EXIT statement to force iteration processing to end before the end
condition is met.
■
Description (Example: Using within IF Statement)
When the condition equation is true, the iteration statement (FOR, WHILE,
REPEAT) is forced to end, and any statements after EXIT will not be exe-
cuted.
Note (1) The condition can also be specified as a boolean variable (BOOL data
type) only rather than an equation.
(2) Even if the condition equation is true before the expression has been ex-
ecuted, the expression will be executed.
■
Example
Processing is repeated from when variable n = 1 until 50 in increments of 1
and n is added to array variable DATA[n]. If DATA[n] exceeds 100, however,
processing will end.