→Input variable

according to →IEC-standard: →variable which is used to supply a value to a →program organization unit except for →class

The ST-syntax for input variables is listed under "Declaration of input variables in ST". 
Information on the declaration of variables in →FBD is listed under "Declaring variables in FBD". Information on the declaration of variables in →LD is listed under "Declaring variables in LD and assigning a variable to contact/coil".