Panasonic FP Series Programming Manual page 543

Bitwise Boolean instructions
Body When the variable start is set to TRUE, the function is carried out.
LD
ST When programming with structured text, enter the following:
IF start THEN
F133_BTT( n:= 0,
d:= value);
IF R900B
bit0_is_TRUE
ELSE
bit0_is_TRUE
END_IF;
END_IF;
542
THEN
:= FALSE;
:= TRUE;