Excluding a Portion of Code With IFDEF Statement

GF_ProjectVX code allows you to exclude from the compilation only a specific portion of code and checking if a certain symbol is defined, using the IFDEF feature.First of all, the IFDEF feature needs to be enabled, since it’s not an IEC standard feature.You can do that by selecting Project>options…>Code generation tab and then checking the Enable preprocessor directives checkbox. This feature is available only in ST, LD and FBD languages.This feature will exclude from compilation the selected code only if a specified symbol has not been defined; the symbol to be specified can be any symbol or POU (program, frun- tion, function block, global variable…) but it must be GLOBALLY VISIBLE.