External Variables - VAR_EXTERNAL¶
External variables are global variables that are imported into a block.
You declare these variables between the keywords VAR_EXTERNAL
and END_VAR
. If the global variable does not exist, then an error message is printed.
Attention
In CODESYS, it is not necessary to declare variables as external. The keyword exists for maintaining compliance with IEC 61131-3.
Example
VAR_EXTERNAL
\ iVarExt1 : INT; (* 1st external variable *)
See also