→Constant
according to →IEC-standard: language element which declares a data element with a fixed value
In the ST-editor, constant →variables are declared by using the keyword CONSTANT
. This keyword is only allowed for the sections VAR
, VAR_GLOBAL
and VAR_EXTERNAL
.In the FBD-editor, constant variables are declared by using the prefix C
(in particular when creating a value field with a new variable). This prefix is only allowed for internal variables, →global variables and →external variables.