IF THEN ELSE ELSIF END_IF
Syntax
IF <BOOL expression> THEN
<statements>
ELSIF <BOOL expression> THEN
<statements>
ELSE
<statements>
END_IF;
Remarks
The IF statement is available in ST"Structured text" A high-level language that is block structured and syntactically resembles Pascal only. The execution of the statements is conditioned by a Boolean expression. ELSIF and ELSE statements are optional. There can be several ELSIF statements.
ST Language
(* simple condition *)
IF bCond THEN
Q1 := IN1;
Q2 := TRUE;
END_IF;
(* binary selection *)
IF bCond THEN
Q1 := IN1;
Q2 := TRUE;
ELSE
Q1 := IN2;
Q2 := FALSE;
END_IF;
(* enumerated conditions *)
IF bCond1 THEN
Q1 := IN1;
ELSIF bCond2 THEN
Q1 := IN2;
ELSIF bCond3 THEN
Q1 := IN3;
ELSE
Q1 := IN4;
END_IF;
FBD Language
Not available
FFLD Language
Not available
IL Language
Not available
See also