ST language commands
The ST language commands are ending by a semicolon. The EOL character is treated in the same way as the space character.
| Command | Description | Example |
|---|---|---|
| := | Assignment. The value calculated on the right is assigned to the identifier on the left. | A := B; C := SIN(X); My_FB(p1 := 10, p2 := 20); |
| ⇒ | Assignment. Value of the variable declared on the left is assigned to the identifier on the right. | FB1(out1 => my_var); |
| REF= | Reference. Variable on the left is filled with reference to the value on the right. | MyVar := 100; MyRef REF= MyVar; MyRef := 200; |
| IF | Selection command. If the BOOLean condition is met the associated command is executed. | IF A > 10 THEN B := 1; ELSE B := 2; END_IF; |
| CASE | Selection command. Execution of a block of commands if the CASE condition is met. | CASE TW OF 1,5: DISPLAY := OVEN_TEMP; 2: DISPLAY := MOTOR_SPEED; ELSE DISPLAY := STATUS; END_CASE; |
| FOR | Iterative command. A loop of block of commands with an initial value, end condition, and increment value. | FOR I := 0 TO 10 BY 2 DO J := J + 3; END_FOR; |
| WHILE | Iterative command. A loop of block of commands with condition for exiting the loop at the beginning. | WHILE J < 10 DO J := J + 2; END_WHILE; |
| REPEAT | Iterative command. A loop of block of commands with condition for exiting the loop at the end. | REPEAT J := J + 2; UNTIL J > 10; |
| EXIT | Exiting the loop. Premature exiting of the command loop. | EXIT; |
| RETURN | Return. Leaving of the currently executed block. | RETURN; |